Inline all format arguments where possible

This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.

The change was automatically created with, so there are far less change
of an accidental typo.

```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```

crates/base-db/src/fixture.rs

@@ -407,9 +407,9 @@ fn parse_crate(crate_str: String) -> (String, CrateOrigin, Option<String>) {
                 Some((version, url)) => {
                     (version, CrateOrigin::CratesIo { repo: Some(url.to_owned()), name: None })
                 }
-                _ => panic!("Bad crates.io parameter: {}", data),
+                _ => panic!("Bad crates.io parameter: {data}"),
             },
-            _ => panic!("Bad string for crate origin: {}", b),
+            _ => panic!("Bad string for crate origin: {b}"),
         };
         (a.to_owned(), origin, Some(version.to_string()))
     } else {
@@ -439,7 +439,7 @@ impl From<Fixture> for FileMeta {
             introduce_new_source_root: f.introduce_new_source_root.map(|kind| match &*kind {
                 "local" => SourceRootKind::Local,
                 "library" => SourceRootKind::Library,
-                invalid => panic!("invalid source root kind '{}'", invalid),
+                invalid => panic!("invalid source root kind '{invalid}'"),
             }),
             target_data_layout: f.target_data_layout,
         }

crates/base-db/src/input.rs

@@ -618,8 +618,8 @@ impl CyclicDependenciesError {
 impl fmt::Display for CyclicDependenciesError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let render = |(id, name): &(CrateId, Option<CrateDisplayName>)| match name {
-            Some(it) => format!("{}({:?})", it, id),
-            None => format!("{:?}", id),
+            Some(it) => format!("{it}({id:?})"),
+            None => format!("{id:?}"),
         };
         let path = self.path.iter().rev().map(render).collect::<Vec<String>>().join(" -> ");
         write!(

crates/base-db/src/lib.rs

@@ -75,7 +75,7 @@ pub trait SourceDatabase: FileLoader + std::fmt::Debug {
 }
 
 fn parse_query(db: &dyn SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
-    let _p = profile::span("parse_query").detail(|| format!("{:?}", file_id));
+    let _p = profile::span("parse_query").detail(|| format!("{file_id:?}"));
     let text = db.file_text(file_id);
     SourceFile::parse(&text)
 }

crates/cfg/src/cfg_expr.rs

@@ -44,7 +44,7 @@ impl fmt::Display for CfgAtom {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             CfgAtom::Flag(name) => name.fmt(f),
-            CfgAtom::KeyValue { key, value } => write!(f, "{} = {:?}", key, value),
+            CfgAtom::KeyValue { key, value } => write!(f, "{key} = {value:?}"),
         }
     }
 }

crates/cfg/src/lib.rs

@@ -37,7 +37,7 @@ impl fmt::Debug for CfgOptions {
             .iter()
             .map(|atom| match atom {
                 CfgAtom::Flag(it) => it.to_string(),
-                CfgAtom::KeyValue { key, value } => format!("{}={}", key, value),
+                CfgAtom::KeyValue { key, value } => format!("{key}={value}"),
             })
             .collect::<Vec<_>>();
         items.sort();
@@ -175,7 +175,7 @@ impl fmt::Display for InactiveReason {
                 atom.fmt(f)?;
             }
             let is_are = if self.enabled.len() == 1 { "is" } else { "are" };
-            write!(f, " {} enabled", is_are)?;
+            write!(f, " {is_are} enabled")?;
 
             if !self.disabled.is_empty() {
                 f.write_str(" and ")?;
@@ -194,7 +194,7 @@ impl fmt::Display for InactiveReason {
                 atom.fmt(f)?;
             }
             let is_are = if self.disabled.len() == 1 { "is" } else { "are" };
-            write!(f, " {} disabled", is_are)?;
+            write!(f, " {is_are} disabled")?;
         }
 
         Ok(())

crates/flycheck/src/lib.rs

@@ -60,9 +60,9 @@ pub enum FlycheckConfig {
 impl fmt::Display for FlycheckConfig {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            FlycheckConfig::CargoCommand { command, .. } => write!(f, "cargo {}", command),
+            FlycheckConfig::CargoCommand { command, .. } => write!(f, "cargo {command}"),
             FlycheckConfig::CustomCommand { command, args, .. } => {
-                write!(f, "{} {}", command, args.join(" "))
+                write!(f, "{command} {}", args.join(" "))
             }
         }
     }
@@ -474,7 +474,7 @@ impl CargoActor {
         );
         match output {
             Ok(_) => Ok((read_at_least_one_message, error)),
-            Err(e) => Err(io::Error::new(e.kind(), format!("{:?}: {}", e, error))),
+            Err(e) => Err(io::Error::new(e.kind(), format!("{e:?}: {error}"))),
         }
     }
 }

crates/hir-def/src/attr.rs

@@ -712,7 +712,7 @@ impl AttrSourceMap {
         self.source
             .get(ast_idx)
             .map(|it| InFile::new(file_id, it))
-            .unwrap_or_else(|| panic!("cannot find attr at index {:?}", id))
+            .unwrap_or_else(|| panic!("cannot find attr at index {id:?}"))
     }
 }
 

crates/hir-def/src/body/pretty.rs

@@ -32,7 +32,7 @@ pub(super) fn print_body_hir(db: &dyn DefDatabase, body: &Body, owner: DefWithBo
                 Some(name) => name.to_string(),
                 None => "_".to_string(),
             };
-            format!("const {} = ", name)
+            format!("const {name} = ")
         }
         DefWithBodyId::VariantId(it) => {
             needs_semi = false;
@@ -42,7 +42,7 @@ pub(super) fn print_body_hir(db: &dyn DefDatabase, body: &Body, owner: DefWithBo
                 Some(name) => name.to_string(),
                 None => "_".to_string(),
             };
-            format!("{}", name)
+            format!("{name}")
         }
     };
 

crates/hir-def/src/find_path.rs

@@ -512,7 +512,7 @@ mod tests {
     fn check_found_path_(ra_fixture: &str, path: &str, prefix_kind: Option<PrefixKind>) {
         let (db, pos) = TestDB::with_position(ra_fixture);
         let module = db.module_at_position(pos);
-        let parsed_path_file = syntax::SourceFile::parse(&format!("use {};", path));
+        let parsed_path_file = syntax::SourceFile::parse(&format!("use {path};"));
         let ast_path =
             parsed_path_file.syntax_node().descendants().find_map(syntax::ast::Path::cast).unwrap();
         let mod_path = ModPath::from_src(&db, ast_path, &Hygiene::new_unhygienic()).unwrap();
@@ -531,7 +531,7 @@ mod tests {
 
         let found_path =
             find_path_inner(&db, ItemInNs::Types(resolved), module, prefix_kind, false);
-        assert_eq!(found_path, Some(mod_path), "{:?}", prefix_kind);
+        assert_eq!(found_path, Some(mod_path), "{prefix_kind:?}");
     }
 
     fn check_found_path(

crates/hir-def/src/import_map.rs

@@ -243,7 +243,7 @@ impl fmt::Debug for ImportMap {
                     ItemInNs::Values(_) => "v",
                     ItemInNs::Macros(_) => "m",
                 };
-                format!("- {} ({})", info.path, ns)
+                format!("- {} ({ns})", info.path)
             })
             .collect();
 
@@ -398,7 +398,7 @@ pub fn search_dependencies<'a>(
     krate: CrateId,
     query: Query,
 ) -> FxHashSet<ItemInNs> {
-    let _p = profile::span("search_dependencies").detail(|| format!("{:?}", query));
+    let _p = profile::span("search_dependencies").detail(|| format!("{query:?}"));
 
     let graph = db.crate_graph();
     let import_maps: Vec<_> =
@@ -549,7 +549,7 @@ mod tests {
                         None
                     }
                 })?;
-            return Some(format!("{}::{}", dependency_imports.path_of(trait_)?, assoc_item_name));
+            return Some(format!("{}::{assoc_item_name}", dependency_imports.path_of(trait_)?));
         }
         None
     }
@@ -589,7 +589,7 @@ mod tests {
 
                 let map = db.import_map(krate);
 
-                Some(format!("{}:\n{:?}\n", name, map))
+                Some(format!("{name}:\n{map:?}\n"))
             })
             .sorted()
             .collect::<String>();

crates/hir-def/src/item_tree.rs

@@ -105,7 +105,7 @@ pub struct ItemTree {
 
 impl ItemTree {
     pub(crate) fn file_item_tree_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<ItemTree> {
-        let _p = profile::span("file_item_tree_query").detail(|| format!("{:?}", file_id));
+        let _p = profile::span("file_item_tree_query").detail(|| format!("{file_id:?}"));
         let syntax = match db.parse_or_expand(file_id) {
             Some(node) => node,
             None => return Default::default(),
@@ -132,7 +132,7 @@ impl ItemTree {
                     ctx.lower_macro_stmts(stmts)
                 },
                 _ => {
-                    panic!("cannot create item tree from {:?} {}", syntax, syntax);
+                    panic!("cannot create item tree from {syntax:?} {syntax}");
                 },
             }
         };

crates/hir-def/src/macro_expansion_tests.rs

@@ -179,7 +179,7 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
             if tree {
                 let tree = format!("{:#?}", parse.syntax_node())
                     .split_inclusive('\n')
-                    .map(|line| format!("// {}", line))
+                    .map(|line| format!("// {line}"))
                     .collect::<String>();
                 format_to!(expn_text, "\n{}", tree)
             }

crates/hir-def/src/nameres.rs

@@ -461,7 +461,7 @@ impl DefMap {
             for (name, child) in
                 map.modules[module].children.iter().sorted_by(|a, b| Ord::cmp(&a.0, &b.0))
             {
-                let path = format!("{}::{}", path, name);
+                let path = format!("{path}::{name}");
                 buf.push('\n');
                 go(buf, map, &path, *child);
             }

crates/hir-def/src/nameres/collector.rs

@@ -1017,7 +1017,7 @@ impl DefCollector<'_> {
                         None => true,
                         Some(old_vis) => {
                             let max_vis = old_vis.max(vis, &self.def_map).unwrap_or_else(|| {
-                                panic!("`Tr as _` imports with unrelated visibilities {:?} and {:?} (trait {:?})", old_vis, vis, tr);
+                                panic!("`Tr as _` imports with unrelated visibilities {old_vis:?} and {vis:?} (trait {tr:?})");
                             });
 
                             if max_vis == old_vis {

crates/hir-def/src/nameres/mod_resolution.rs

@@ -74,12 +74,12 @@ impl ModDir {
                 candidate_files.push(self.dir_path.join_attr(attr_path, self.root_non_dir_owner))
             }
             None if file_id.is_include_macro(db.upcast()) => {
-                candidate_files.push(format!("{}.rs", name));
-                candidate_files.push(format!("{}/mod.rs", name));
+                candidate_files.push(format!("{name}.rs"));
+                candidate_files.push(format!("{name}/mod.rs"));
             }
             None => {
-                candidate_files.push(format!("{}{}.rs", self.dir_path.0, name));
-                candidate_files.push(format!("{}{}/mod.rs", self.dir_path.0, name));
+                candidate_files.push(format!("{}{name}.rs", self.dir_path.0));
+                candidate_files.push(format!("{}{name}/mod.rs", self.dir_path.0));
             }
         };
 
@@ -91,7 +91,7 @@ impl ModDir {
                 let (dir_path, root_non_dir_owner) = if is_mod_rs || attr_path.is_some() {
                     (DirPath::empty(), false)
                 } else {
-                    (DirPath::new(format!("{}/", name)), true)
+                    (DirPath::new(format!("{name}/")), true)
                 };
                 if let Some(mod_dir) = self.child(dir_path, root_non_dir_owner) {
                     return Ok((file_id, is_mod_rs, mod_dir));
@@ -156,7 +156,7 @@ impl DirPath {
         } else {
             attr
         };
-        let res = format!("{}{}", base, attr);
+        let res = format!("{base}{attr}");
         res
     }
 }

crates/hir-def/src/nameres/path_resolution.rs

@@ -170,8 +170,8 @@ impl DefMap {
     ) -> ResolvePathResult {
         let graph = db.crate_graph();
         let _cx = stdx::panic_context::enter(format!(
-            "DefMap {:?} crate_name={:?} block={:?} path={}",
-            self.krate, graph[self.krate].display_name, self.block, path
+            "DefMap {:?} crate_name={:?} block={:?} path={path}",
+            self.krate, graph[self.krate].display_name, self.block
         ));
 
         let mut segments = path.segments().iter().enumerate();

crates/hir-def/src/nameres/tests/incremental.rs

@@ -13,7 +13,7 @@ fn check_def_map_is_not_recomputed(ra_fixture_initial: &str, ra_fixture_change:
         let events = db.log_executed(|| {
             db.crate_def_map(krate);
         });
-        assert!(format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
+        assert!(format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
     db.set_file_text(pos.file_id, Arc::new(ra_fixture_change.to_string()));
 
@@ -21,7 +21,7 @@ fn check_def_map_is_not_recomputed(ra_fixture_initial: &str, ra_fixture_change:
         let events = db.log_executed(|| {
             db.crate_def_map(krate);
         });
-        assert!(!format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
+        assert!(!format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
 }
 
@@ -94,7 +94,7 @@ fn typing_inside_a_macro_should_not_invalidate_def_map() {
             let (_, module_data) = crate_def_map.modules.iter().last().unwrap();
             assert_eq!(module_data.scope.resolutions().count(), 1);
         });
-        assert!(format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
+        assert!(format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
     db.set_file_text(pos.file_id, Arc::new("m!(Y);".to_string()));
 
@@ -104,7 +104,7 @@ fn typing_inside_a_macro_should_not_invalidate_def_map() {
             let (_, module_data) = crate_def_map.modules.iter().last().unwrap();
             assert_eq!(module_data.scope.resolutions().count(), 1);
         });
-        assert!(!format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
+        assert!(!format!("{events:?}").contains("crate_def_map"), "{events:#?}")
     }
 }
 

crates/hir-def/src/pretty.rs

@@ -92,7 +92,7 @@ pub(crate) fn print_generic_args(generics: &GenericArgs, buf: &mut dyn Write) ->
 pub(crate) fn print_generic_arg(arg: &GenericArg, buf: &mut dyn Write) -> fmt::Result {
     match arg {
         GenericArg::Type(ty) => print_type_ref(ty, buf),
-        GenericArg::Const(c) => write!(buf, "{}", c),
+        GenericArg::Const(c) => write!(buf, "{c}"),
         GenericArg::Lifetime(lt) => write!(buf, "{}", lt.name),
     }
 }
@@ -118,7 +118,7 @@ pub(crate) fn print_type_ref(type_ref: &TypeRef, buf: &mut dyn Write) -> fmt::Re
                 Mutability::Shared => "*const",
                 Mutability::Mut => "*mut",
             };
-            write!(buf, "{} ", mtbl)?;
+            write!(buf, "{mtbl} ")?;
             print_type_ref(pointee, buf)?;
         }
         TypeRef::Reference(pointee, lt, mtbl) => {
@@ -130,13 +130,13 @@ pub(crate) fn print_type_ref(type_ref: &TypeRef, buf: &mut dyn Write) -> fmt::Re
             if let Some(lt) = lt {
                 write!(buf, "{} ", lt.name)?;
             }
-            write!(buf, "{}", mtbl)?;
+            write!(buf, "{mtbl}")?;
             print_type_ref(pointee, buf)?;
         }
         TypeRef::Array(elem, len) => {
             write!(buf, "[")?;
             print_type_ref(elem, buf)?;
-            write!(buf, "; {}]", len)?;
+            write!(buf, "; {len}]")?;
         }
         TypeRef::Slice(elem) => {
             write!(buf, "[")?;

crates/hir-expand/src/db.rs

@@ -444,7 +444,7 @@ fn macro_expand(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<Option<Ar
         // be reported at the definition site (when we construct a def map).
         Err(err) => {
             return ExpandResult::only_err(ExpandError::Other(
-                format!("invalid macro definition: {}", err).into(),
+                format!("invalid macro definition: {err}").into(),
             ))
         }
     };

crates/hir-expand/src/eager.rs

@@ -161,7 +161,7 @@ pub fn expand_eager_macro(
 
         Ok(Ok(db.intern_macro_call(loc)))
     } else {
-        panic!("called `expand_eager_macro` on non-eager macro def {:?}", def);
+        panic!("called `expand_eager_macro` on non-eager macro def {def:?}");
     }
 }
 

crates/hir-expand/src/fixup.rs

@@ -366,7 +366,7 @@ mod tests {
             fixups.append,
         );
 
-        let actual = format!("{}\n", tt);
+        let actual = format!("{tt}\n");
 
         expect.indent(false);
         expect.assert_eq(&actual);

crates/hir-expand/src/quote.rs

@@ -233,7 +233,7 @@ mod tests {
 
         let quoted = quote!(#a);
         assert_eq!(quoted.to_string(), "hello");
-        let t = format!("{:?}", quoted);
+        let t = format!("{quoted:?}");
         assert_eq!(t, "SUBTREE $\n  IDENT   hello 4294967295");
     }
 

crates/hir-ty/src/builder.rs

@@ -142,7 +142,7 @@ impl<D> TyBuilder<D> {
         match (a.data(Interner), e) {
             (chalk_ir::GenericArgData::Ty(_), ParamKind::Type)
             | (chalk_ir::GenericArgData::Const(_), ParamKind::Const(_)) => (),
-            _ => panic!("Mismatched kinds: {:?}, {:?}, {:?}", a, self.vec, self.param_kinds),
+            _ => panic!("Mismatched kinds: {a:?}, {:?}, {:?}", self.vec, self.param_kinds),
         }
     }
 }

crates/hir-ty/src/consteval.rs

@@ -90,14 +90,14 @@ impl Display for ComputedExpr {
             ComputedExpr::Literal(l) => match l {
                 Literal::Int(x, _) => {
                     if *x >= 10 {
-                        write!(f, "{} ({:#X})", x, x)
+                        write!(f, "{x} ({x:#X})")
                     } else {
                         x.fmt(f)
                     }
                 }
                 Literal::Uint(x, _) => {
                     if *x >= 10 {
-                        write!(f, "{} ({:#X})", x, x)
+                        write!(f, "{x} ({x:#X})")
                     } else {
                         x.fmt(f)
                     }

crates/hir-ty/src/consteval/tests.rs

@@ -14,7 +14,7 @@ fn check_number(ra_fixture: &str, answer: i128) {
     match r {
         ComputedExpr::Literal(Literal::Int(r, _)) => assert_eq!(r, answer),
         ComputedExpr::Literal(Literal::Uint(r, _)) => assert_eq!(r, answer as u128),
-        x => panic!("Expected number but found {:?}", x),
+        x => panic!("Expected number but found {x:?}"),
     }
 }
 
@@ -126,7 +126,7 @@ fn enums() {
             assert_eq!(name, "E::A");
             assert_eq!(val, 1);
         }
-        x => panic!("Expected enum but found {:?}", x),
+        x => panic!("Expected enum but found {x:?}"),
     }
 }
 

crates/hir-ty/src/diagnostics/match_check.rs

@@ -386,7 +386,7 @@ impl HirDisplay for Pat {
                 }
                 subpattern.hir_fmt(f)
             }
-            PatKind::LiteralBool { value } => write!(f, "{}", value),
+            PatKind::LiteralBool { value } => write!(f, "{value}"),
             PatKind::Or { pats } => f.write_joined(pats.iter(), " | "),
         }
     }

crates/hir-ty/src/diagnostics/match_check/deconstruct_pat.rs

@@ -372,7 +372,7 @@ impl Constructor {
                     hir_def::AdtId::UnionId(id) => id.into(),
                 }
             }
-            _ => panic!("bad constructor {:?} for adt {:?}", self, adt),
+            _ => panic!("bad constructor {self:?} for adt {adt:?}"),
         }
     }
 

crates/hir-ty/src/display.rs

@@ -176,13 +176,13 @@ impl<'a> HirFormatter<'a> {
         let mut first = true;
         for e in iter {
             if !first {
-                write!(self, "{}", sep)?;
+                write!(self, "{sep}")?;
             }
             first = false;
 
             // Abbreviate multiple omitted types with a single ellipsis.
             if self.should_truncate() {
-                return write!(self, "{}", TYPE_HINT_TRUNCATION);
+                return write!(self, "{TYPE_HINT_TRUNCATION}");
             }
 
             e.hir_fmt(self)?;
@@ -320,7 +320,7 @@ impl<T: HirDisplay + Internable> HirDisplay for Interned<T> {
 impl HirDisplay for ProjectionTy {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+            return write!(f, "{TYPE_HINT_TRUNCATION}");
         }
 
         let trait_ref = self.trait_ref(f.db);
@@ -342,7 +342,7 @@ impl HirDisplay for ProjectionTy {
 impl HirDisplay for OpaqueTy {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+            return write!(f, "{TYPE_HINT_TRUNCATION}");
         }
 
         self.substitution.at(Interner, 0).hir_fmt(f)
@@ -385,7 +385,7 @@ impl HirDisplay for BoundVar {
 impl HirDisplay for Ty {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+            return write!(f, "{TYPE_HINT_TRUNCATION}");
         }
 
         match self.kind(Interner) {
@@ -572,7 +572,7 @@ impl HirDisplay for Ty {
                             hir_def::AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
                             hir_def::AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
                         };
-                        write!(f, "{}", name)?;
+                        write!(f, "{name}")?;
                     }
                     DisplayTarget::SourceCode { module_id } => {
                         if let Some(path) = find_path::find_path(
@@ -581,7 +581,7 @@ impl HirDisplay for Ty {
                             module_id,
                             false,
                         ) {
-                            write!(f, "{}", path)?;
+                            write!(f, "{path}")?;
                         } else {
                             return Err(HirDisplayError::DisplaySourceCodeError(
                                 DisplaySourceCodeError::PathNotFound,
@@ -737,7 +737,7 @@ impl HirDisplay for Ty {
                     if sig.params().is_empty() {
                         write!(f, "||")?;
                     } else if f.should_truncate() {
-                        write!(f, "|{}|", TYPE_HINT_TRUNCATION)?;
+                        write!(f, "|{TYPE_HINT_TRUNCATION}|")?;
                     } else {
                         write!(f, "|")?;
                         f.write_joined(sig.params(), ", ")?;
@@ -928,7 +928,7 @@ pub fn write_bounds_like_dyn_trait_with_prefix(
     default_sized: SizedByDefault,
     f: &mut HirFormatter<'_>,
 ) -> Result<(), HirDisplayError> {
-    write!(f, "{}", prefix)?;
+    write!(f, "{prefix}")?;
     if !predicates.is_empty()
         || predicates.is_empty() && matches!(default_sized, SizedByDefault::Sized { .. })
     {
@@ -1056,7 +1056,7 @@ fn fmt_trait_ref(
     use_as: bool,
 ) -> Result<(), HirDisplayError> {
     if f.should_truncate() {
-        return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        return write!(f, "{TYPE_HINT_TRUNCATION}");
     }
 
     tr.self_type_parameter(Interner).hir_fmt(f)?;
@@ -1083,7 +1083,7 @@ impl HirDisplay for TraitRef {
 impl HirDisplay for WhereClause {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+            return write!(f, "{TYPE_HINT_TRUNCATION}");
         }
 
         match self {
@@ -1197,7 +1197,7 @@ impl HirDisplay for TypeRef {
                     hir_def::type_ref::Mutability::Shared => "*const ",
                     hir_def::type_ref::Mutability::Mut => "*mut ",
                 };
-                write!(f, "{}", mutability)?;
+                write!(f, "{mutability}")?;
                 inner.hir_fmt(f)?;
             }
             TypeRef::Reference(inner, lifetime, mutability) => {
@@ -1209,13 +1209,13 @@ impl HirDisplay for TypeRef {
                 if let Some(lifetime) = lifetime {
                     write!(f, "{} ", lifetime.name)?;
                 }
-                write!(f, "{}", mutability)?;
+                write!(f, "{mutability}")?;
                 inner.hir_fmt(f)?;
             }
             TypeRef::Array(inner, len) => {
                 write!(f, "[")?;
                 inner.hir_fmt(f)?;
-                write!(f, "; {}]", len)?;
+                write!(f, "; {len}]")?;
             }
             TypeRef::Slice(inner) => {
                 write!(f, "[")?;
@@ -1232,7 +1232,7 @@ impl HirDisplay for TypeRef {
                     for index in 0..function_parameters.len() {
                         let (param_name, param_type) = &function_parameters[index];
                         if let Some(name) = param_name {
-                            write!(f, "{}: ", name)?;
+                            write!(f, "{name}: ")?;
                         }
 
                         param_type.hir_fmt(f)?;
@@ -1408,7 +1408,7 @@ impl HirDisplay for hir_def::path::GenericArg {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         match self {
             hir_def::path::GenericArg::Type(ty) => ty.hir_fmt(f),
-            hir_def::path::GenericArg::Const(c) => write!(f, "{}", c),
+            hir_def::path::GenericArg::Const(c) => write!(f, "{c}"),
             hir_def::path::GenericArg::Lifetime(lifetime) => write!(f, "{}", lifetime.name),
         }
     }

crates/hir-ty/src/interner.rs

@@ -143,7 +143,7 @@ impl chalk_ir::interner::Interner for Interner {
 
     fn debug_goal(goal: &Goal<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
         let goal_data = goal.data(Interner);
-        Some(write!(fmt, "{:?}", goal_data))
+        Some(write!(fmt, "{goal_data:?}"))
     }
 
     fn debug_goals(

crates/hir-ty/src/lib.rs

@@ -513,7 +513,7 @@ where
     let mut error_replacer = ErrorReplacer { vars: 0 };
     let value = match t.clone().try_fold_with(&mut error_replacer, DebruijnIndex::INNERMOST) {
         Ok(t) => t,
-        Err(_) => panic!("Encountered unbound or inference vars in {:?}", t),
+        Err(_) => panic!("Encountered unbound or inference vars in {t:?}"),
     };
     let kinds = (0..error_replacer.vars).map(|_| {
         chalk_ir::CanonicalVarKind::new(

crates/hir-ty/src/tests.rs

@@ -105,7 +105,7 @@ fn check_impl(ra_fixture: &str, allow_none: bool, only_types: bool, display_sour
                         .collect(),
                 );
             } else {
-                panic!("unexpected annotation: {}", expected);
+                panic!("unexpected annotation: {expected}");
             }
             had_annotations = true;
         }
@@ -181,11 +181,11 @@ fn check_impl(ra_fixture: &str, allow_none: bool, only_types: bool, display_sour
                         expected,
                         adjustments
                             .iter()
-                            .map(|Adjustment { kind, .. }| format!("{:?}", kind))
+                            .map(|Adjustment { kind, .. }| format!("{kind:?}"))
                             .collect::<Vec<_>>()
                     );
                 } else {
-                    panic!("expected {:?} adjustments, found none", expected);
+                    panic!("expected {expected:?} adjustments, found none");
                 }
             }
         }

crates/hir-ty/src/tests/incremental.rs

@@ -24,7 +24,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
                 db.infer(def);
             });
         });
-        assert!(format!("{:?}", events).contains("infer"))
+        assert!(format!("{events:?}").contains("infer"))
     }
 
     let new_text = "
@@ -46,6 +46,6 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
                 db.infer(def);
             });
         });
-        assert!(!format!("{:?}", events).contains("infer"), "{:#?}", events)
+        assert!(!format!("{events:?}").contains("infer"), "{events:#?}")
     }
 }

crates/hir-ty/src/tests/macros.rs

@@ -849,7 +849,7 @@ fn main() {
   //^^^^^^^^^^^^^^^^^ RegisterBlock
 }
     "#;
-    let fixture = format!("{}\n//- /foo.rs\n{}", fixture, data);
+    let fixture = format!("{fixture}\n//- /foo.rs\n{data}");
 
     {
         let _b = bench("include macro");

crates/hir-ty/src/tls.rs

@@ -67,12 +67,12 @@ impl DebugContext<'_> {
         let trait_ref = projection_ty.trait_ref(self.0);
         let trait_params = trait_ref.substitution.as_slice(Interner);
         let self_ty = trait_ref.self_type_parameter(Interner);
-        write!(fmt, "<{:?} as {}", self_ty, trait_name)?;
+        write!(fmt, "<{self_ty:?} as {trait_name}")?;
         if trait_params.len() > 1 {
             write!(
                 fmt,
                 "<{}>",
-                trait_params[1..].iter().format_with(", ", |x, f| f(&format_args!("{:?}", x))),
+                trait_params[1..].iter().format_with(", ", |x, f| f(&format_args!("{x:?}"))),
             )?;
         }
         write!(fmt, ">::{}", type_alias_data.name)?;
@@ -83,7 +83,7 @@ impl DebugContext<'_> {
             write!(
                 fmt,
                 "<{}>",
-                proj_params.iter().format_with(", ", |x, f| f(&format_args!("{:?}", x))),
+                proj_params.iter().format_with(", ", |x, f| f(&format_args!("{x:?}"))),
             )?;
         }
 
@@ -105,9 +105,9 @@ impl DebugContext<'_> {
             }
         };
         match def {
-            CallableDefId::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
+            CallableDefId::FunctionId(_) => write!(fmt, "{{fn {name}}}"),
             CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {
-                write!(fmt, "{{ctor {}}}", name)
+                write!(fmt, "{{ctor {name}}}")
             }
         }
     }

crates/hir-ty/src/traits.rs

@@ -130,7 +130,7 @@ fn solve(
 
     let mut solve = || {
         let _ctx = if is_chalk_debug() || is_chalk_print() {
-            Some(panic_context::enter(format!("solving {:?}", goal)))
+            Some(panic_context::enter(format!("solving {goal:?}")))
         } else {
             None
         };

crates/hir/src/attrs.rs

@@ -148,7 +148,7 @@ fn resolve_doc_path(
 
     let modpath = {
         // FIXME: this is not how we should get a mod path here
-        let ast_path = ast::SourceFile::parse(&format!("type T = {};", link))
+        let ast_path = ast::SourceFile::parse(&format!("type T = {link};"))
             .syntax_node()
             .descendants()
             .find_map(ast::Path::cast)?;

crates/hir/src/display.rs

@@ -79,7 +79,7 @@ impl HirDisplay for Function {
                 }
             }
             match name {
-                Some(name) => write!(f, "{}: ", name)?,
+                Some(name) => write!(f, "{name}: ")?,
                 None => f.write_str("_: ")?,
             }
             // FIXME: Use resolved `param.ty` or raw `type_ref`?
@@ -327,7 +327,7 @@ fn write_generic_params(
                         continue;
                     }
                     delim(f)?;
-                    write!(f, "{}", name)?;
+                    write!(f, "{name}")?;
                     if let Some(default) = &ty.default {
                         f.write_str(" = ")?;
                         default.hir_fmt(f)?;
@@ -335,7 +335,7 @@ fn write_generic_params(
                 }
                 TypeOrConstParamData::ConstParamData(c) => {
                     delim(f)?;
-                    write!(f, "const {}: ", name)?;
+                    write!(f, "const {name}: ")?;
                     c.ty.hir_fmt(f)?;
                 }
             }
@@ -372,7 +372,7 @@ fn write_where_clause(def: GenericDefId, f: &mut HirFormatter<'_>) -> Result<(),
         WherePredicateTypeTarget::TypeRef(ty) => ty.hir_fmt(f),
         WherePredicateTypeTarget::TypeOrConstParam(id) => {
             match &params.type_or_consts[*id].name() {
-                Some(name) => write!(f, "{}", name),
+                Some(name) => write!(f, "{name}"),
                 None => f.write_str("{unnamed}"),
             }
         }
@@ -424,7 +424,7 @@ fn write_where_clause(def: GenericDefId, f: &mut HirFormatter<'_>) -> Result<(),
                         if idx != 0 {
                             f.write_str(", ")?;
                         }
-                        write!(f, "{}", lifetime)?;
+                        write!(f, "{lifetime}")?;
                     }
                     f.write_str("> ")?;
                     write_target(target, f)?;
@@ -447,7 +447,7 @@ impl HirDisplay for Const {
         let data = f.db.const_data(self.id);
         f.write_str("const ")?;
         match &data.name {
-            Some(name) => write!(f, "{}: ", name)?,
+            Some(name) => write!(f, "{name}: ")?,
             None => f.write_str("_: ")?,
         }
         data.type_ref.hir_fmt(f)?;
@@ -511,9 +511,9 @@ impl HirDisplay for Module {
     fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {
         // FIXME: Module doesn't have visibility saved in data.
         match self.name(f.db) {
-            Some(name) => write!(f, "mod {}", name),
+            Some(name) => write!(f, "mod {name}"),
             None if self.is_crate_root(f.db) => match self.krate(f.db).display_name(f.db) {
-                Some(name) => write!(f, "extern crate {}", name),
+                Some(name) => write!(f, "extern crate {name}"),
                 None => f.write_str("extern crate {unknown}"),
             },
             None => f.write_str("mod {unnamed}"),

crates/hir/src/lib.rs

@@ -813,7 +813,7 @@ fn precise_macro_call_location(
                 .doc_comments_and_attrs()
                 .nth((*invoc_attr_index) as usize)
                 .and_then(Either::left)
-                .unwrap_or_else(|| panic!("cannot find attribute #{}", invoc_attr_index));
+                .unwrap_or_else(|| panic!("cannot find attribute #{invoc_attr_index}"));
 
             (
                 ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&attr))),

crates/hir/src/semantics.rs

@@ -1378,7 +1378,7 @@ impl<'db> SemanticsImpl<'db> {
                 self.cache
                     .borrow()
                     .keys()
-                    .map(|it| format!("{:?}", it))
+                    .map(|it| format!("{it:?}"))
                     .collect::<Vec<_>>()
                     .join(", ")
             )

crates/ide-assists/src/handlers/generate_delegate_methods.rs

@@ -81,7 +81,7 @@ pub(crate) fn generate_delegate_methods(acc: &mut Assists, ctx: &AssistContext<'
         acc.add_group(
             &GroupLabel("Generate delegate methods…".to_owned()),
             AssistId("generate_delegate_methods", AssistKind::Generate),
-            format!("Generate delegate for `{}.{}()`", field_name, method.name(ctx.db())),
+            format!("Generate delegate for `{field_name}.{}()`", method.name(ctx.db())),
             target,
             |builder| {
                 // Create the function

crates/ide-assists/src/handlers/generate_enum_projection_method.rs

@@ -157,7 +157,7 @@ fn generate_enum_projection_method(
         assist_description,
         target,
         |builder| {
-            let vis = parent_enum.visibility().map_or(String::new(), |v| format!("{} ", v));
+            let vis = parent_enum.visibility().map_or(String::new(), |v| format!("{v} "));
 
             let field_type_syntax = field_type.syntax();
 

crates/ide-assists/src/handlers/generate_getter.rs

@@ -235,7 +235,7 @@ fn generate_getter_from_info(
 ) -> String {
     let mut buf = String::with_capacity(512);
 
-    let vis = info.strukt.visibility().map_or(String::new(), |v| format!("{} ", v));
+    let vis = info.strukt.visibility().map_or(String::new(), |v| format!("{v} "));
     let (ty, body) = if info.mutable {
         (
             format!("&mut {}", record_field_info.field_ty),

crates/ide-assists/src/tests.rs

@@ -171,7 +171,7 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult<'_>, assist_la
                     }
                     FileSystemEdit::MoveDir { src, src_id, dst } => {
                         // temporary placeholder for MoveDir since we are not using MoveDir in ide assists yet.
-                        (dst, format!("{:?}\n{:?}", src_id, src))
+                        (dst, format!("{src_id:?}\n{src:?}"))
                     }
                 };
                 let sr = db.file_source_root(dst.anchor);

crates/ide-assists/src/tests/sourcegen.rs

@@ -18,7 +18,7 @@ use super::check_doc_test;
         for assist in assists.iter() {
             for (idx, section) in assist.sections.iter().enumerate() {
                 let test_id =
-                    if idx == 0 { assist.id.clone() } else { format!("{}_{}", &assist.id, idx) };
+                    if idx == 0 { assist.id.clone() } else { format!("{}_{idx}", &assist.id) };
                 let test = format!(
                     r######"
 #[test]
@@ -175,7 +175,7 @@ impl fmt::Display for Assist {
 fn hide_hash_comments(text: &str) -> String {
     text.split('\n') // want final newline
         .filter(|&it| !(it.starts_with("# ") || it == "#"))
-        .map(|it| format!("{}\n", it))
+        .map(|it| format!("{it}\n"))
         .collect()
 }
 
@@ -190,6 +190,6 @@ fn reveal_hash_comments(text: &str) -> String {
                 it
             }
         })
-        .map(|it| format!("{}\n", it))
+        .map(|it| format!("{it}\n"))
         .collect()
 }

crates/ide-completion/src/completions.rs

@@ -133,7 +133,7 @@ impl Completions {
                 if incomplete_let && snippet.ends_with('}') {
                     // complete block expression snippets with a trailing semicolon, if inside an incomplete let
                     cov_mark::hit!(let_semi);
-                    item.insert_snippet(cap, format!("{};", snippet));
+                    item.insert_snippet(cap, format!("{snippet};"));
                 } else {
                     item.insert_snippet(cap, snippet);
                 }

crates/ide-completion/src/completions/attribute/cfg.rs

@@ -11,7 +11,7 @@ use crate::{completions::Completions, context::CompletionContext, CompletionItem
 pub(crate) fn complete_cfg(acc: &mut Completions, ctx: &CompletionContext<'_>) {
     let add_completion = |item: &str| {
         let mut completion = CompletionItem::new(SymbolKind::BuiltinAttr, ctx.source_range(), item);
-        completion.insert_text(format!(r#""{}""#, item));
+        completion.insert_text(format!(r#""{item}""#));
         acc.add(completion.build());
     };
 
@@ -29,7 +29,7 @@ pub(crate) fn complete_cfg(acc: &mut Completions, ctx: &CompletionContext<'_>) {
         Some("target_vendor") => KNOWN_VENDOR.iter().copied().for_each(add_completion),
         Some("target_endian") => ["little", "big"].into_iter().for_each(add_completion),
         Some(name) => ctx.krate.potential_cfg(ctx.db).get_cfg_values(name).cloned().for_each(|s| {
-            let insert_text = format!(r#""{}""#, s);
+            let insert_text = format!(r#""{s}""#);
             let mut item = CompletionItem::new(SymbolKind::BuiltinAttr, ctx.source_range(), s);
             item.insert_text(insert_text);
 

crates/ide-completion/src/completions/attribute/lint.rs

@@ -51,7 +51,7 @@ pub(super) fn complete_lint(
             continue;
         }
         let label = match qual {
-            Some(qual) if !is_qualified => format!("{}::{}", qual, name),
+            Some(qual) if !is_qualified => format!("{qual}::{name}"),
             _ => name.to_owned(),
         };
         let mut item = CompletionItem::new(SymbolKind::Attribute, ctx.source_range(), label);

crates/ide-completion/src/completions/env_vars.rs

@@ -112,7 +112,7 @@ mod tests {
         "#;
 
         let completions = completion_list(fixture);
-        assert!(completions.is_empty(), "Completions weren't empty: {}", completions);
+        assert!(completions.is_empty(), "Completions weren't empty: {completions}");
     }
 
     #[test]
@@ -129,7 +129,7 @@ mod tests {
         "#;
 
         let completions = completion_list(fixture);
-        assert!(completions.is_empty(), "Completions weren't empty: {}", completions);
+        assert!(completions.is_empty(), "Completions weren't empty: {completions}");
     }
 
     #[test]
@@ -145,6 +145,6 @@ mod tests {
         "#;
 
         let completions = completion_list(fixture);
-        assert!(completions.is_empty(), "Completions weren't empty: {}", completions)
+        assert!(completions.is_empty(), "Completions weren't empty: {completions}")
     }
 }

crates/ide-completion/src/completions/fn_param.rs

@@ -192,5 +192,5 @@ fn comma_wrapper(ctx: &CompletionContext<'_>) -> Option<(impl Fn(&str) -> String
         matches!(prev_token_kind, SyntaxKind::COMMA | SyntaxKind::L_PAREN | SyntaxKind::PIPE);
     let leading = if has_leading_comma { "" } else { ", " };
 
-    Some((move |label: &_| (format!("{}{}{}", leading, label, trailing)), param.text_range()))
+    Some((move |label: &_| (format!("{leading}{label}{trailing}")), param.text_range()))
 }

crates/ide-completion/src/completions/item_list/trait_impl.rs

@@ -190,7 +190,7 @@ fn add_function_impl(
     };
 
     let mut item = CompletionItem::new(completion_kind, replacement_range, label);
-    item.lookup_by(format!("fn {}", fn_name))
+    item.lookup_by(format!("fn {fn_name}"))
         .set_documentation(func.docs(ctx.db))
         .set_relevance(CompletionRelevance { is_item_from_trait: true, ..Default::default() });
 
@@ -205,11 +205,11 @@ fn add_function_impl(
             let function_decl = function_declaration(&transformed_fn, source.file_id.is_macro());
             match ctx.config.snippet_cap {
                 Some(cap) => {
-                    let snippet = format!("{} {{\n    $0\n}}", function_decl);
+                    let snippet = format!("{function_decl} {{\n    $0\n}}");
                     item.snippet_edit(cap, TextEdit::replace(replacement_range, snippet));
                 }
                 None => {
-                    let header = format!("{} {{", function_decl);
+                    let header = format!("{function_decl} {{");
                     item.text_edit(TextEdit::replace(replacement_range, header));
                 }
             };
@@ -249,10 +249,10 @@ fn add_type_alias_impl(
 ) {
     let alias_name = type_alias.name(ctx.db).unescaped().to_smol_str();
 
-    let label = format!("type {} =", alias_name);
+    let label = format!("type {alias_name} =");
 
     let mut item = CompletionItem::new(SymbolKind::TypeAlias, replacement_range, label);
-    item.lookup_by(format!("type {}", alias_name))
+    item.lookup_by(format!("type {alias_name}"))
         .set_documentation(type_alias.docs(ctx.db))
         .set_relevance(CompletionRelevance { is_item_from_trait: true, ..Default::default() });
 
@@ -290,7 +290,7 @@ fn add_type_alias_impl(
 
             match ctx.config.snippet_cap {
                 Some(cap) => {
-                    let snippet = format!("{}$0;", decl);
+                    let snippet = format!("{decl}$0;");
                     item.snippet_edit(cap, TextEdit::replace(replacement_range, snippet));
                 }
                 None => {
@@ -321,10 +321,10 @@ fn add_const_impl(
                 };
 
                 let label = make_const_compl_syntax(&transformed_const, source.file_id.is_macro());
-                let replacement = format!("{} ", label);
+                let replacement = format!("{label} ");
 
                 let mut item = CompletionItem::new(SymbolKind::Const, replacement_range, label);
-                item.lookup_by(format!("const {}", const_name))
+                item.lookup_by(format!("const {const_name}"))
                     .set_documentation(const_.docs(ctx.db))
                     .set_relevance(CompletionRelevance {
                         is_item_from_trait: true,
@@ -333,7 +333,7 @@ fn add_const_impl(
                 match ctx.config.snippet_cap {
                     Some(cap) => item.snippet_edit(
                         cap,
-                        TextEdit::replace(replacement_range, format!("{}$0;", replacement)),
+                        TextEdit::replace(replacement_range, format!("{replacement}$0;")),
                     ),
                     None => item.text_edit(TextEdit::replace(replacement_range, replacement)),
                 };

crates/ide-completion/src/completions/postfix.rs

@@ -61,7 +61,7 @@ pub(crate) fn complete_postfix(
                 let mut item = postfix_snippet(
                     "drop",
                     "fn drop(&mut self)",
-                    &format!("drop($0{})", receiver_text),
+                    &format!("drop($0{receiver_text})"),
                 );
                 item.set_documentation(drop_fn.docs(ctx.db));
                 item.add_to(acc);
@@ -76,14 +76,14 @@ pub(crate) fn complete_postfix(
                 postfix_snippet(
                     "ifl",
                     "if let Ok {}",
-                    &format!("if let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                    &format!("if let Ok($1) = {receiver_text} {{\n    $0\n}}"),
                 )
                 .add_to(acc);
 
                 postfix_snippet(
                     "while",
                     "while let Ok {}",
-                    &format!("while let Ok($1) = {} {{\n    $0\n}}", receiver_text),
+                    &format!("while let Ok($1) = {receiver_text} {{\n    $0\n}}"),
                 )
                 .add_to(acc);
             }
@@ -91,41 +91,37 @@ pub(crate) fn complete_postfix(
                 postfix_snippet(
                     "ifl",
                     "if let Some {}",
-                    &format!("if let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                    &format!("if let Some($1) = {receiver_text} {{\n    $0\n}}"),
                 )
                 .add_to(acc);
 
                 postfix_snippet(
                     "while",
                     "while let Some {}",
-                    &format!("while let Some($1) = {} {{\n    $0\n}}", receiver_text),
+                    &format!("while let Some($1) = {receiver_text} {{\n    $0\n}}"),
                 )
                 .add_to(acc);
             }
         }
     } else if receiver_ty.is_bool() || receiver_ty.is_unknown() {
-        postfix_snippet("if", "if expr {}", &format!("if {} {{\n    $0\n}}", receiver_text))
+        postfix_snippet("if", "if expr {}", &format!("if {receiver_text} {{\n    $0\n}}"))
             .add_to(acc);
-        postfix_snippet(
-            "while",
-            "while expr {}",
-            &format!("while {} {{\n    $0\n}}", receiver_text),
-        )
+        postfix_snippet("while", "while expr {}", &format!("while {receiver_text} {{\n    $0\n}}"))
             .add_to(acc);
-        postfix_snippet("not", "!expr", &format!("!{}", receiver_text)).add_to(acc);
+        postfix_snippet("not", "!expr", &format!("!{receiver_text}")).add_to(acc);
     } else if let Some(trait_) = ctx.famous_defs().core_iter_IntoIterator() {
         if receiver_ty.impls_trait(ctx.db, trait_, &[]) {
             postfix_snippet(
                 "for",
                 "for ele in expr {}",
-                &format!("for ele in {} {{\n    $0\n}}", receiver_text),
+                &format!("for ele in {receiver_text} {{\n    $0\n}}"),
             )
             .add_to(acc);
         }
     }
 
-    postfix_snippet("ref", "&expr", &format!("&{}", receiver_text)).add_to(acc);
-    postfix_snippet("refm", "&mut expr", &format!("&mut {}", receiver_text)).add_to(acc);
+    postfix_snippet("ref", "&expr", &format!("&{receiver_text}")).add_to(acc);
+    postfix_snippet("refm", "&mut expr", &format!("&mut {receiver_text}")).add_to(acc);
 
     // The rest of the postfix completions create an expression that moves an argument,
     // so it's better to consider references now to avoid breaking the compilation
@@ -148,7 +144,7 @@ pub(crate) fn complete_postfix(
                 postfix_snippet(
                     "match",
                     "match expr {}",
-                    &format!("match {} {{\n    Ok(${{1:_}}) => {{$2}},\n    Err(${{3:_}}) => {{$0}},\n}}", receiver_text),
+                    &format!("match {receiver_text} {{\n    Ok(${{1:_}}) => {{$2}},\n    Err(${{3:_}}) => {{$0}},\n}}"),
                 )
                 .add_to(acc);
             }
@@ -168,21 +164,21 @@ pub(crate) fn complete_postfix(
             postfix_snippet(
                 "match",
                 "match expr {}",
-                &format!("match {} {{\n    ${{1:_}} => {{$0}},\n}}", receiver_text),
+                &format!("match {receiver_text} {{\n    ${{1:_}} => {{$0}},\n}}"),
             )
             .add_to(acc);
         }
     }
 
-    postfix_snippet("box", "Box::new(expr)", &format!("Box::new({})", receiver_text)).add_to(acc);
-    postfix_snippet("dbg", "dbg!(expr)", &format!("dbg!({})", receiver_text)).add_to(acc); // fixme
-    postfix_snippet("dbgr", "dbg!(&expr)", &format!("dbg!(&{})", receiver_text)).add_to(acc);
-    postfix_snippet("call", "function(expr)", &format!("${{1}}({})", receiver_text)).add_to(acc);
+    postfix_snippet("box", "Box::new(expr)", &format!("Box::new({receiver_text})")).add_to(acc);
+    postfix_snippet("dbg", "dbg!(expr)", &format!("dbg!({receiver_text})")).add_to(acc); // fixme
+    postfix_snippet("dbgr", "dbg!(&expr)", &format!("dbg!(&{receiver_text})")).add_to(acc);
+    postfix_snippet("call", "function(expr)", &format!("${{1}}({receiver_text})")).add_to(acc);
 
     if let Some(parent) = dot_receiver.syntax().parent().and_then(|p| p.parent()) {
         if matches!(parent.kind(), STMT_LIST | EXPR_STMT) {
-            postfix_snippet("let", "let", &format!("let $0 = {};", receiver_text)).add_to(acc);
-            postfix_snippet("letm", "let mut", &format!("let mut $0 = {};", receiver_text))
+            postfix_snippet("let", "let", &format!("let $0 = {receiver_text};")).add_to(acc);
+            postfix_snippet("letm", "let mut", &format!("let mut $0 = {receiver_text};"))
                 .add_to(acc);
         }
     }
@@ -300,7 +296,7 @@ fn add_custom_postfix_completions(
             let body = snippet.postfix_snippet(receiver_text);
             let mut builder =
                 postfix_snippet(trigger, snippet.description.as_deref().unwrap_or_default(), &body);
-            builder.documentation(Documentation::new(format!("```rust\n{}\n```", body)));
+            builder.documentation(Documentation::new(format!("```rust\n{body}\n```")));
             for import in imports.into_iter() {
                 builder.add_import(import);
             }

crates/ide-completion/src/completions/postfix/format_like.rs

@@ -54,7 +54,7 @@ pub(crate) fn add_format_like_completions(
     if let Ok((out, exprs)) = parse_format_exprs(receiver_text.text()) {
         let exprs = with_placeholders(exprs);
         for (label, macro_name) in KINDS {
-            let snippet = format!(r#"{}({}, {})"#, macro_name, out, exprs.join(", "));
+            let snippet = format!(r#"{macro_name}({out}, {})"#, exprs.join(", "));
 
             postfix_snippet(label, macro_name, &snippet).add_to(acc);
         }
@@ -81,7 +81,7 @@ mod tests {
         for (kind, input, output) in test_vector {
             let (parsed_string, exprs) = parse_format_exprs(input).unwrap();
             let exprs = with_placeholders(exprs);
-            let snippet = format!(r#"{}("{}", {})"#, kind, parsed_string, exprs.join(", "));
+            let snippet = format!(r#"{kind}("{parsed_string}", {})"#, exprs.join(", "));
             assert_eq!(&snippet, output);
         }
     }

crates/ide-completion/src/completions/snippet.rs

@@ -141,7 +141,7 @@ fn add_custom_completions(
             };
             let body = snip.snippet();
             let mut builder = snippet(ctx, cap, trigger, &body);
-            builder.documentation(Documentation::new(format!("```rust\n{}\n```", body)));
+            builder.documentation(Documentation::new(format!("```rust\n{body}\n```")));
             for import in imports.into_iter() {
                 builder.add_import(import);
             }

crates/ide-completion/src/context/tests.rs

@@ -19,7 +19,7 @@ fn check_expected_type_and_name(ra_fixture: &str, expect: Expect) {
     let name =
         completion_context.expected_name.map_or_else(|| "?".to_owned(), |name| name.to_string());
 
-    expect.assert_eq(&format!("ty: {}, name: {}", ty, name));
+    expect.assert_eq(&format!("ty: {ty}, name: {name}"));
 }
 
 #[test]

crates/ide-completion/src/item.rs

@@ -453,10 +453,10 @@ impl Builder {
             // snippets can have multiple imports, but normal completions only have up to one
             if let Some(original_path) = import_edit.original_path.as_ref() {
                 lookup = lookup.or_else(|| Some(label.clone()));
-                label = SmolStr::from(format!("{} (use {})", label, original_path));
+                label = SmolStr::from(format!("{label} (use {original_path})"));
             }
         } else if let Some(trait_name) = self.trait_name {
-            label = SmolStr::from(format!("{} (as {})", label, trait_name));
+            label = SmolStr::from(format!("{label} (as {trait_name})"));
         }
 
         let text_edit = match self.text_edit {

crates/ide-completion/src/render.rs

@@ -144,8 +144,7 @@ pub(crate) fn render_field(
 }
 
 fn field_with_receiver(receiver: Option<&hir::Name>, field_name: &str) -> SmolStr {
-    receiver
-        .map_or_else(|| field_name.into(), |receiver| format!("{}.{}", receiver, field_name).into())
+    receiver.map_or_else(|| field_name.into(), |receiver| format!("{receiver}.{field_name}").into())
 }
 
 pub(crate) fn render_tuple_field(
@@ -306,7 +305,7 @@ fn render_resolution_path(
                 item.lookup_by(name.clone())
                     .label(SmolStr::from_iter([&name, "<…>"]))
                     .trigger_call_info()
-                    .insert_snippet(cap, format!("{}<$0>", local_name));
+                    .insert_snippet(cap, format!("{local_name}<$0>"));
             }
         }
     }
@@ -528,13 +527,13 @@ mod tests {
 
                 let tag = it.kind().tag();
                 let relevance = display_relevance(it.relevance());
-                items.push(format!("{} {} {}\n", tag, it.label(), relevance));
+                items.push(format!("{tag} {} {relevance}\n", it.label()));
 
                 if let Some((mutability, _offset, relevance)) = it.ref_match() {
                     let label = format!("&{}{}", mutability.as_keyword_for_ref(), it.label());
                     let relevance = display_relevance(relevance);
 
-                    items.push(format!("{} {} {}\n", tag, label, relevance));
+                    items.push(format!("{tag} {label} {relevance}\n"));
                 }
 
                 items
@@ -563,7 +562,7 @@ mod tests {
             .filter_map(|(cond, desc)| if cond { Some(desc) } else { None })
             .join("+");
 
-            format!("[{}]", relevance_factors)
+            format!("[{relevance_factors}]")
         }
     }
 

crates/ide-completion/src/render/function.rs

@@ -53,7 +53,7 @@ fn render(
     let (call, escaped_call) = match &func_kind {
         FuncKind::Method(_, Some(receiver)) => (
             format!("{}.{}", receiver.unescaped(), name.unescaped()).into(),
-            format!("{}.{}", receiver, name).into(),
+            format!("{receiver}.{name}").into(),
         ),
         _ => (name.unescaped().to_smol_str(), name.to_smol_str()),
     };
@@ -162,7 +162,7 @@ pub(super) fn add_call_parens<'b>(
     cov_mark::hit!(inserts_parens_for_function_calls);
 
     let (snippet, label_suffix) = if self_param.is_none() && params.is_empty() {
-        (format!("{}()$0", escaped_name), "()")
+        (format!("{escaped_name}()$0"), "()")
     } else {
         builder.trigger_call_info();
         let snippet = if let Some(CallableSnippets::FillArguments) = ctx.config.callable {
@@ -174,7 +174,7 @@ pub(super) fn add_call_parens<'b>(
                             let smol_str = n.to_smol_str();
                             let text = smol_str.as_str().trim_start_matches('_');
                             let ref_ = ref_of_param(ctx, text, param.ty());
-                            f(&format_args!("${{{}:{}{}}}", index + offset, ref_, text))
+                            f(&format_args!("${{{}:{ref_}{text}}}", index + offset))
                         }
                         None => {
                             let name = match param.ty().as_adt() {
@@ -185,7 +185,7 @@ pub(super) fn add_call_parens<'b>(
                                     .map(|s| to_lower_snake_case(s.as_str()))
                                     .unwrap_or_else(|| "_".to_string()),
                             };
-                            f(&format_args!("${{{}:{}}}", index + offset, name))
+                            f(&format_args!("${{{}:{name}}}", index + offset))
                         }
                     }
                 });
@@ -200,12 +200,12 @@ pub(super) fn add_call_parens<'b>(
                     )
                 }
                 None => {
-                    format!("{}({})$0", escaped_name, function_params_snippet)
+                    format!("{escaped_name}({function_params_snippet})$0")
                 }
             }
         } else {
             cov_mark::hit!(suppress_arg_snippets);
-            format!("{}($0)", escaped_name)
+            format!("{escaped_name}($0)")
         };
 
         (snippet, "(…)")

crates/ide-completion/src/render/macro_.rs

@@ -66,7 +66,7 @@ fn render(
 
     match ctx.snippet_cap() {
         Some(cap) if needs_bang && !has_call_parens => {
-            let snippet = format!("{}!{}$0{}", escaped_name, bra, ket);
+            let snippet = format!("{escaped_name}!{bra}$0{ket}");
             let lookup = banged_name(&name);
             item.insert_snippet(cap, snippet).lookup_by(lookup);
         }

crates/ide-completion/src/render/variant.rs

@@ -35,8 +35,8 @@ pub(crate) fn render_record_lit(
     });
 
     RenderedLiteral {
-        literal: format!("{} {{ {} }}", path, completions),
-        detail: format!("{} {{ {} }}", path, types),
+        literal: format!("{path} {{ {completions} }}"),
+        detail: format!("{path} {{ {types} }}"),
     }
 }
 
@@ -49,7 +49,7 @@ pub(crate) fn render_tuple_lit(
     path: &str,
 ) -> RenderedLiteral {
     if snippet_cap.is_none() {
-        return RenderedLiteral { literal: format!("{}", path), detail: format!("{}", path) };
+        return RenderedLiteral { literal: format!("{path}"), detail: format!("{path}") };
     }
     let completions = fields.iter().enumerate().format_with(", ", |(idx, _), f| {
         if snippet_cap.is_some() {
@@ -62,8 +62,8 @@ pub(crate) fn render_tuple_lit(
     let types = fields.iter().format_with(", ", |field, f| f(&field.ty(db).display(db)));
 
     RenderedLiteral {
-        literal: format!("{}({})", path, completions),
-        detail: format!("{}({})", path, types),
+        literal: format!("{path}({completions})"),
+        detail: format!("{path}({types})"),
     }
 }
 

crates/ide-completion/src/snippet.rs

@@ -199,7 +199,7 @@ fn validate_snippet(
 ) -> Option<(Box<[GreenNode]>, String, Option<Box<str>>)> {
     let mut imports = Vec::with_capacity(requires.len());
     for path in requires.iter() {
-        let use_path = ast::SourceFile::parse(&format!("use {};", path))
+        let use_path = ast::SourceFile::parse(&format!("use {path};"))
             .syntax_node()
             .descendants()
             .find_map(ast::Path::cast)?;

crates/ide-completion/src/tests.rs

@@ -153,7 +153,7 @@ fn render_completion_list(completions: Vec<CompletionItem>) -> String {
         .into_iter()
         .map(|it| {
             let tag = it.kind().tag();
-            let var_name = format!("{} {}", tag, it.label());
+            let var_name = format!("{tag} {}", it.label());
             let mut buf = var_name;
             if let Some(detail) = it.detail() {
                 let width = label_width.saturating_sub(monospace_width(it.label()));
@@ -188,7 +188,7 @@ pub(crate) fn check_edit_with_config(
         .iter()
         .filter(|it| it.lookup() == what)
         .collect_tuple()
-        .unwrap_or_else(|| panic!("can't find {:?} completion in {:#?}", what, completions));
+        .unwrap_or_else(|| panic!("can't find {what:?} completion in {completions:#?}"));
     let mut actual = db.file_text(position.file_id).to_string();
 
     let mut combined_edit = completion.text_edit().to_owned();

crates/ide-completion/src/tests/expression.rs

@@ -4,7 +4,7 @@ use expect_test::{expect, Expect};
 use crate::tests::{check_edit, completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-completion/src/tests/item.rs

@@ -7,7 +7,7 @@ use expect_test::{expect, Expect};
 use crate::tests::{completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-completion/src/tests/item_list.rs

@@ -4,7 +4,7 @@ use expect_test::{expect, Expect};
 use crate::tests::{check_edit, completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-completion/src/tests/pattern.rs

@@ -9,7 +9,7 @@ fn check_empty(ra_fixture: &str, expect: Expect) {
 }
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}\n{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}\n{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-completion/src/tests/predicate.rs

@@ -4,7 +4,7 @@ use expect_test::{expect, Expect};
 use crate::tests::{completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}\n{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}\n{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-completion/src/tests/type_pos.rs

@@ -4,7 +4,7 @@ use expect_test::{expect, Expect};
 use crate::tests::{completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
-    let actual = completion_list(&format!("{}\n{}", BASE_ITEMS_FIXTURE, ra_fixture));
+    let actual = completion_list(&format!("{BASE_ITEMS_FIXTURE}\n{ra_fixture}"));
     expect.assert_eq(&actual)
 }
 

crates/ide-db/src/assists.rs

@@ -88,7 +88,7 @@ impl FromStr for AssistKind {
             "RefactorExtract" => Ok(AssistKind::RefactorExtract),
             "RefactorInline" => Ok(AssistKind::RefactorInline),
             "RefactorRewrite" => Ok(AssistKind::RefactorRewrite),
-            unknown => Err(format!("Unknown AssistKind: '{}'", unknown)),
+            unknown => Err(format!("Unknown AssistKind: '{unknown}'")),
         }
     }
 }

crates/ide-db/src/imports/import_assets.rs

@@ -367,7 +367,7 @@ fn import_for_item(
     let expected_import_end = if item_as_assoc(db, original_item).is_some() {
         unresolved_qualifier.to_string()
     } else {
-        format!("{}::{}", unresolved_qualifier, item_name(db, original_item)?)
+        format!("{unresolved_qualifier}::{}", item_name(db, original_item)?)
     };
     if !import_path_string.contains(unresolved_first_segment)
         || !import_path_string.ends_with(&expected_import_end)

crates/ide-db/src/imports/insert_use/tests.rs

@@ -1014,7 +1014,7 @@ fn check_with_config(
         .and_then(|it| ImportScope::find_insert_use_container(&it, sema))
         .or_else(|| ImportScope::from(syntax))
         .unwrap();
-    let path = ast::SourceFile::parse(&format!("use {};", path))
+    let path = ast::SourceFile::parse(&format!("use {path};"))
         .tree()
         .syntax()
         .descendants()

crates/ide-db/src/rename.rs

@@ -197,7 +197,7 @@ fn rename_mod(
 
         // Module exists in a named file
         if !is_mod_rs {
-            let path = format!("{}.rs", new_name);
+            let path = format!("{new_name}.rs");
             let dst = AnchoredPathBuf { anchor, path };
             source_change.push_file_system_edit(FileSystemEdit::MoveFile { src: anchor, dst })
         }
@@ -207,9 +207,7 @@ fn rename_mod(
         //  - Module has submodules defined in separate files
         let dir_paths = match (is_mod_rs, has_detached_child, module.name(sema.db)) {
             // Go up one level since the anchor is inside the dir we're trying to rename
-            (true, _, Some(mod_name)) => {
-                Some((format!("../{}", mod_name), format!("../{}", new_name)))
-            }
+            (true, _, Some(mod_name)) => Some((format!("../{mod_name}"), format!("../{new_name}"))),
             // The anchor is on the same level as target dir
             (false, true, Some(mod_name)) => Some((mod_name.to_string(), new_name.to_string())),
             _ => None,
@@ -356,7 +354,7 @@ fn source_edit_from_name(edit: &mut TextEditBuilder, name: &ast::Name, new_name:
 
             // FIXME: instead of splitting the shorthand, recursively trigger a rename of the
             // other name https://github.com/rust-lang/rust-analyzer/issues/6547
-            edit.insert(ident_pat.syntax().text_range().start(), format!("{}: ", new_name));
+            edit.insert(ident_pat.syntax().text_range().start(), format!("{new_name}: "));
             return true;
         }
     }
@@ -414,7 +412,7 @@ fn source_edit_from_name_ref(
                 // Foo { field } -> Foo { new_name: field }
                 //       ^ insert `new_name: `
                 let offset = name_ref.syntax().text_range().start();
-                edit.insert(offset, format!("{}: ", new_name));
+                edit.insert(offset, format!("{new_name}: "));
                 return true;
             }
             (None, Some(_)) if matches!(def, Definition::Local(_)) => {
@@ -422,7 +420,7 @@ fn source_edit_from_name_ref(
                 // Foo { field } -> Foo { field: new_name }
                 //            ^ insert `: new_name`
                 let offset = name_ref.syntax().text_range().end();
-                edit.insert(offset, format!(": {}", new_name));
+                edit.insert(offset, format!(": {new_name}"));
                 return true;
             }
             _ => (),

crates/ide-db/src/symbol_index.rs

@@ -206,7 +206,7 @@ pub fn world_symbols(db: &RootDatabase, query: Query) -> Vec<FileSymbol> {
 }
 
 pub fn crate_symbols(db: &RootDatabase, krate: Crate, query: Query) -> Vec<FileSymbol> {
-    let _p = profile::span("crate_symbols").detail(|| format!("{:?}", query));
+    let _p = profile::span("crate_symbols").detail(|| format!("{query:?}"));
 
     let modules = krate.modules(db);
     let indices: Vec<_> = modules

crates/ide-db/src/syntax_helpers/format_string_exprs.rs

@@ -205,7 +205,7 @@ mod tests {
     fn check(input: &str, expect: &Expect) {
         let (output, exprs) = parse_format_exprs(input).unwrap_or(("-".to_string(), vec![]));
         let outcome_repr = if !exprs.is_empty() {
-            format!("{}; {}", output, with_placeholders(exprs).join(", "))
+            format!("{output}; {}", with_placeholders(exprs).join(", "))
         } else {
             output
         };

crates/ide-db/src/tests/sourcegen_lints.rs

@@ -241,9 +241,9 @@ fn generate_descriptor_clippy(buf: &mut String, path: &Path) {
 
     buf.push_str(r#"pub const CLIPPY_LINT_GROUPS: &[LintGroup] = &["#);
     for (id, children) in clippy_groups {
-        let children = children.iter().map(|id| format!("clippy::{}", id)).collect::<Vec<_>>();
+        let children = children.iter().map(|id| format!("clippy::{id}")).collect::<Vec<_>>();
         if !children.is_empty() {
-            let lint_ident = format!("clippy::{}", id);
+            let lint_ident = format!("clippy::{id}");
             let description = format!("lint group for: {}", children.iter().join(", "));
             push_lint_group(buf, &lint_ident, &description, &children);
         }
@@ -273,7 +273,7 @@ fn push_lint_group(buf: &mut String, label: &str, description: &str, children: &
 
     push_lint_completion(buf, label, description);
 
-    let children = format!("&[{}]", children.iter().map(|it| format!("\"{}\"", it)).join(", "));
+    let children = format!("&[{}]", children.iter().map(|it| format!("\"{it}\"")).join(", "));
     format_to!(
         buf,
         r###"

crates/ide-diagnostics/src/handlers/mismatched_arg_count.rs

@@ -13,7 +13,7 @@ pub(crate) fn mismatched_arg_count(
     d: &hir::MismatchedArgCount,
 ) -> Diagnostic {
     let s = if d.expected == 1 { "" } else { "s" };
-    let message = format!("expected {} argument{}, found {}", d.expected, s, d.found);
+    let message = format!("expected {} argument{s}, found {}", d.expected, d.found);
     Diagnostic::new("mismatched-arg-count", message, invalid_args_range(ctx, d))
 }
 

crates/ide-diagnostics/src/handlers/no_such_field.rs

@@ -78,13 +78,13 @@ fn missing_record_expr_field_fixes(
 
     let mut new_field = new_field.to_string();
     if usage_file_id != def_file_id {
-        new_field = format!("pub(crate) {}", new_field);
+        new_field = format!("pub(crate) {new_field}");
     }
-    new_field = format!("\n{}{}", indent, new_field);
+    new_field = format!("\n{indent}{new_field}");
 
     let needs_comma = !last_field_syntax.to_string().ends_with(',');
     if needs_comma {
-        new_field = format!(",{}", new_field);
+        new_field = format!(",{new_field}");
     }
 
     let source_change = SourceChange::from_text_edit(

crates/ide-diagnostics/src/handlers/type_mismatch.rs

@@ -106,11 +106,11 @@ fn add_missing_ok_or_some(
     }
 
     let mut builder = TextEdit::builder();
-    builder.insert(expr.syntax().text_range().start(), format!("{}(", variant_name));
+    builder.insert(expr.syntax().text_range().start(), format!("{variant_name}("));
     builder.insert(expr.syntax().text_range().end(), ")".to_string());
     let source_change =
         SourceChange::from_text_edit(d.expr.file_id.original_file(ctx.sema.db), builder.finish());
-    let name = format!("Wrap in {}", variant_name);
+    let name = format!("Wrap in {variant_name}");
     acc.push(fix("wrap_in_constructor", &name, source_change, expr_range));
     Some(())
 }

crates/ide-diagnostics/src/handlers/unlinked_file.rs

@@ -64,7 +64,7 @@ fn fixes(ctx: &DiagnosticsContext<'_>, file_id: FileId) -> Option<Vec<Assist>> {
         // `submod/bla.rs` -> `submod.rs`
         let parent_mod = (|| {
             let (name, _) = parent.name_and_extension()?;
-            parent.parent()?.join(&format!("{}.rs", name))
+            parent.parent()?.join(&format!("{name}.rs"))
         })();
         paths.extend(parent_mod);
         paths
@@ -99,8 +99,8 @@ fn make_fixes(
         matches!(item, ast::Item::Module(m) if m.item_list().is_none())
     }
 
-    let mod_decl = format!("mod {};", new_mod_name);
-    let pub_mod_decl = format!("pub mod {};", new_mod_name);
+    let mod_decl = format!("mod {new_mod_name};");
+    let pub_mod_decl = format!("pub mod {new_mod_name};");
 
     let ast: ast::SourceFile = db.parse(parent_file_id).tree();
 
@@ -125,8 +125,8 @@ fn make_fixes(
         Some(last) => {
             cov_mark::hit!(unlinked_file_append_to_existing_mods);
             let offset = last.syntax().text_range().end();
-            mod_decl_builder.insert(offset, format!("\n{}", mod_decl));
-            pub_mod_decl_builder.insert(offset, format!("\n{}", pub_mod_decl));
+            mod_decl_builder.insert(offset, format!("\n{mod_decl}"));
+            pub_mod_decl_builder.insert(offset, format!("\n{pub_mod_decl}"));
         }
         None => {
             // Prepend before the first item in the file.
@@ -134,15 +134,15 @@ fn make_fixes(
                 Some(item) => {
                     cov_mark::hit!(unlinked_file_prepend_before_first_item);
                     let offset = item.syntax().text_range().start();
-                    mod_decl_builder.insert(offset, format!("{}\n\n", mod_decl));
-                    pub_mod_decl_builder.insert(offset, format!("{}\n\n", pub_mod_decl));
+                    mod_decl_builder.insert(offset, format!("{mod_decl}\n\n"));
+                    pub_mod_decl_builder.insert(offset, format!("{pub_mod_decl}\n\n"));
                 }
                 None => {
                     // No items in the file, so just append at the end.
                     cov_mark::hit!(unlinked_file_empty_file);
                     let offset = ast.syntax().text_range().end();
-                    mod_decl_builder.insert(offset, format!("{}\n", mod_decl));
-                    pub_mod_decl_builder.insert(offset, format!("{}\n", pub_mod_decl));
+                    mod_decl_builder.insert(offset, format!("{mod_decl}\n"));
+                    pub_mod_decl_builder.insert(offset, format!("{pub_mod_decl}\n"));
                 }
             }
         }
@@ -152,13 +152,13 @@ fn make_fixes(
     Some(vec![
         fix(
             "add_mod_declaration",
-            &format!("Insert `{}`", mod_decl),
+            &format!("Insert `{mod_decl}`"),
             SourceChange::from_text_edit(parent_file_id, mod_decl_builder.finish()),
             trigger_range,
         ),
         fix(
             "add_pub_mod_declaration",
-            &format!("Insert `{}`", pub_mod_decl),
+            &format!("Insert `{pub_mod_decl}`"),
             SourceChange::from_text_edit(parent_file_id, pub_mod_decl_builder.finish()),
             trigger_range,
         ),

crates/ide-diagnostics/src/handlers/unresolved_macro_call.rs

@@ -13,7 +13,7 @@ pub(crate) fn unresolved_macro_call(
     let bang = if d.is_bang { "!" } else { "" };
     Diagnostic::new(
         "unresolved-macro-call",
-        format!("unresolved macro `{}{}`", d.path, bang),
+        format!("unresolved macro `{}{bang}`", d.path),
         display_range,
     )
     .experimental()

crates/ide-diagnostics/src/handlers/unresolved_module.rs

@@ -16,7 +16,7 @@ pub(crate) fn unresolved_module(
         "unresolved-module",
         match &*d.candidates {
             [] => "unresolved module".to_string(),
-            [candidate] => format!("unresolved module, can't find module file: {}", candidate),
+            [candidate] => format!("unresolved module, can't find module file: {candidate}"),
             [candidates @ .., last] => {
                 format!(
                     "unresolved module, can't find module file: {}, or {}",

crates/ide-diagnostics/src/handlers/unresolved_proc_macro.rs

@@ -26,7 +26,7 @@ pub(crate) fn unresolved_proc_macro(
     };
 
     let message = match &d.macro_name {
-        Some(name) => format!("proc macro `{}` not expanded", name),
+        Some(name) => format!("proc macro `{name}` not expanded"),
         None => "proc macro not expanded".to_string(),
     };
     let severity = if config_enabled { Severity::Error } else { Severity::WeakWarning };

crates/ide-diagnostics/src/lib.rs

@@ -218,7 +218,7 @@ pub fn diagnostics(
     // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
     res.extend(
         parse.errors().iter().take(128).map(|err| {
-            Diagnostic::new("syntax-error", format!("Syntax Error: {}", err), err.range())
+            Diagnostic::new("syntax-error", format!("Syntax Error: {err}"), err.range())
         }),
     );
 

crates/ide-diagnostics/src/tests.rs

@@ -75,7 +75,7 @@ pub(crate) fn check_no_fix(ra_fixture: &str) {
     )
     .pop()
     .unwrap();
-    assert!(diagnostic.fixes.is_none(), "got a fix when none was expected: {:?}", diagnostic);
+    assert!(diagnostic.fixes.is_none(), "got a fix when none was expected: {diagnostic:?}");
 }
 
 pub(crate) fn check_expect(ra_fixture: &str, expect: Expect) {

crates/ide-diagnostics/src/tests/sourcegen.rs

@@ -39,7 +39,7 @@ impl Diagnostic {
             for block in comment_blocks {
                 let id = block.id;
                 if let Err(msg) = is_valid_diagnostic_name(&id) {
-                    panic!("invalid diagnostic name: {:?}:\n  {}", id, msg)
+                    panic!("invalid diagnostic name: {id:?}:\n  {msg}")
                 }
                 let doc = block.contents.join("\n");
                 let location = sourcegen::Location { file: path.clone(), line: block.line };

crates/ide-ssr/src/parsing.rs

@@ -352,7 +352,7 @@ impl NodeKind {
 impl Placeholder {
     fn new(name: SmolStr, constraints: Vec<Constraint>) -> Self {
         Self {
-            stand_in_name: format!("__placeholder_{}", name),
+            stand_in_name: format!("__placeholder_{name}"),
             constraints,
             ident: Var(name.to_string()),
         }

crates/ide-ssr/src/tests.rs

@@ -121,7 +121,7 @@ fn print_match_debug_info(match_finder: &MatchFinder<'_>, file_id: FileId, snipp
         snippet
     );
     for (index, d) in debug_info.iter().enumerate() {
-        println!("Node #{}\n{:#?}\n", index, d);
+        println!("Node #{index}\n{d:#?}\n");
     }
 }
 
@@ -144,7 +144,7 @@ fn assert_no_match(pattern: &str, code: &str) {
     let matches = match_finder.matches().flattened().matches;
     if !matches.is_empty() {
         print_match_debug_info(&match_finder, position.file_id, &matches[0].matched_text());
-        panic!("Got {} matches when we expected none: {:#?}", matches.len(), matches);
+        panic!("Got {} matches when we expected none: {matches:#?}", matches.len());
     }
 }
 

crates/ide/src/doc_links.rs

@@ -453,7 +453,7 @@ fn get_doc_base_url(db: &RootDatabase, def: Definition) -> Option<Url> {
             })?
         }
     };
-    Url::parse(&base).ok()?.join(&format!("{}/", display_name)).ok()
+    Url::parse(&base).ok()?.join(&format!("{display_name}/")).ok()
 }
 
 /// Get the filename and extension generated for a symbol by rustdoc.
@@ -488,7 +488,7 @@ fn filename_and_frag_for_def(
                 Some(kw) => {
                     format!("keyword.{}.html", kw.trim_matches('"'))
                 }
-                None => format!("{}/index.html", name),
+                None => format!("{name}/index.html"),
             },
             None => String::from("index.html"),
         },

crates/ide/src/doc_links/intra_doc_links.rs

@@ -63,8 +63,8 @@ mod tests {
 
     fn check(link: &str, expected: Expect) {
         let (l, a) = parse_intra_doc_link(link);
-        let a = a.map_or_else(String::new, |a| format!(" ({:?})", a));
-        expected.assert_eq(&format!("{}{}", l, a));
+        let a = a.map_or_else(String::new, |a| format!(" ({a:?})"));
+        expected.assert_eq(&format!("{l}{a}"));
     }
 
     #[test]

crates/ide/src/doc_links/tests.rs

@@ -40,7 +40,7 @@ fn check_doc_links(ra_fixture: &str) {
         .into_iter()
         .map(|(_, link, ns)| {
             let def = resolve_doc_path_for_def(sema.db, cursor_def, &link, ns)
-                .unwrap_or_else(|| panic!("Failed to resolve {}", link));
+                .unwrap_or_else(|| panic!("Failed to resolve {link}"));
             let nav_target = def.try_to_nav(sema.db).unwrap();
             let range =
                 FileRange { file_id: nav_target.file_id, range: nav_target.focus_or_full_range() };

crates/ide/src/goto_definition.rs

@@ -187,7 +187,7 @@ mod tests {
         let (analysis, position) = fixture::position(ra_fixture);
         let navs = analysis.goto_definition(position).unwrap().expect("no definition found").info;
 
-        assert!(navs.is_empty(), "didn't expect this to resolve anywhere: {:?}", navs)
+        assert!(navs.is_empty(), "didn't expect this to resolve anywhere: {navs:?}")
     }
 
     #[test]

crates/ide/src/hover.rs

@@ -163,7 +163,7 @@ pub(crate) fn hover(
                 .filter_map(|(def, node)| hover_for_definition(sema, file_id, def, &node, config))
                 .reduce(|mut acc: HoverResult, HoverResult { markup, actions }| {
                     acc.actions.extend(actions);
-                    acc.markup = Markup::from(format!("{}\n---\n{}", acc.markup, markup));
+                    acc.markup = Markup::from(format!("{}\n---\n{markup}", acc.markup));
                     acc
                 })
         })

crates/ide/src/hover/render.rs

@@ -417,8 +417,8 @@ pub(super) fn definition(
         Definition::Variant(it) => label_value_and_docs(db, it, |&it| {
             if !it.parent_enum(db).is_data_carrying(db) {
                 match it.eval(db) {
-                    Ok(x) => Some(format!("{}", x)),
-                    Err(_) => it.value(db).map(|x| format!("{:?}", x)),
+                    Ok(x) => Some(format!("{x}")),
+                    Err(_) => it.value(db).map(|x| format!("{x:?}")),
                 }
             } else {
                 None
@@ -427,7 +427,7 @@ pub(super) fn definition(
         Definition::Const(it) => label_value_and_docs(db, it, |it| {
             let body = it.eval(db);
             match body {
-                Ok(x) => Some(format!("{}", x)),
+                Ok(x) => Some(format!("{x}")),
                 Err(_) => {
                     let source = it.source(db)?;
                     let mut body = source.value.body()?.syntax().clone();
@@ -483,7 +483,7 @@ pub(super) fn definition(
 
 fn render_builtin_attr(db: &RootDatabase, attr: hir::BuiltinAttr) -> Option<Markup> {
     let name = attr.name(db);
-    let desc = format!("#[{}]", name);
+    let desc = format!("#[{name}]");
 
     let AttributeTemplate { word, list, name_value_str } = match attr.template(db) {
         Some(template) => template,
@@ -522,7 +522,7 @@ where
     V: Display,
 {
     let label = if let Some(value) = value_extractor(&def) {
-        format!("{} // {}", def.display(db), value)
+        format!("{} // {value}", def.display(db))
     } else {
         def.display(db).to_string()
     };
@@ -541,7 +541,7 @@ where
     V: Display,
 {
     let label = if let Some(value) = value_extractor(&def) {
-        format!("{} = {}", def.display(db), value)
+        format!("{} = {value}", def.display(db))
     } else {
         def.display(db).to_string()
     };
@@ -605,9 +605,9 @@ fn local(db: &RootDatabase, it: hir::Local) -> Option<Markup> {
             } else {
                 ""
             };
-            format!("{}{}{}: {}", let_kw, is_mut, name, ty)
+            format!("{let_kw}{is_mut}{name}: {ty}")
         }
-        Either::Right(_) => format!("{}self: {}", is_mut, ty),
+        Either::Right(_) => format!("{is_mut}self: {ty}"),
     };
     markup(None, desc, None)
 }

crates/ide/src/hover/tests.rs

@@ -37,7 +37,7 @@ fn check(ra_fixture: &str, expect: Expect) {
     let content = analysis.db.file_text(position.file_id);
     let hovered_element = &content[hover.range];
 
-    let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+    let actual = format!("*{hovered_element}*\n{}\n", hover.info.markup);
     expect.assert_eq(&actual)
 }
 
@@ -58,7 +58,7 @@ fn check_hover_no_links(ra_fixture: &str, expect: Expect) {
     let content = analysis.db.file_text(position.file_id);
     let hovered_element = &content[hover.range];
 
-    let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+    let actual = format!("*{hovered_element}*\n{}\n", hover.info.markup);
     expect.assert_eq(&actual)
 }
 
@@ -79,7 +79,7 @@ fn check_hover_no_markdown(ra_fixture: &str, expect: Expect) {
     let content = analysis.db.file_text(position.file_id);
     let hovered_element = &content[hover.range];
 
-    let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+    let actual = format!("*{hovered_element}*\n{}\n", hover.info.markup);
     expect.assert_eq(&actual)
 }
 

crates/ide/src/inlay_hints.rs

@@ -468,7 +468,7 @@ mod tests {
             .collect::<Vec<_>>();
         expected.sort_by_key(|(range, _)| range.start());
 
-        assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
+        assert_eq!(expected, actual, "\nExpected:\n{expected:#?}\n\nActual:\n{actual:#?}");
     }
 
     #[track_caller]

crates/ide/src/inlay_hints/bind_pat.rs

@@ -160,7 +160,7 @@ fn is_named_constructor(
     let ctor_name = match qual_seg.kind()? {
         ast::PathSegmentKind::Name(name_ref) => {
             match qual_seg.generic_arg_list().map(|it| it.generic_args()) {
-                Some(generics) => format!("{}<{}>", name_ref, generics.format(", ")),
+                Some(generics) => format!("{name_ref}<{}>", generics.format(", ")),
                 None => name_ref.to_string(),
             }
         }
@@ -473,7 +473,7 @@ fn main() {
             .unwrap();
         let actual =
             inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
-        assert_eq!(expected, actual, "\nExpected:\n{:#?}\n\nActual:\n{:#?}", expected, actual);
+        assert_eq!(expected, actual, "\nExpected:\n{expected:#?}\n\nActual:\n{actual:#?}");
     }
 
     #[test]

crates/ide/src/markup.rs

@@ -33,6 +33,6 @@ impl Markup {
         self.text.as_str()
     }
     pub fn fenced_block(contents: &impl fmt::Display) -> Markup {
-        format!("```rust\n{}\n```", contents).into()
+        format!("```rust\n{contents}\n```").into()
     }
 }

crates/ide/src/moniker.rs

@@ -273,7 +273,7 @@ mod tests {
     fn no_moniker(ra_fixture: &str) {
         let (analysis, position) = fixture::position(ra_fixture);
         if let Some(x) = analysis.moniker(position).unwrap() {
-            assert_eq!(x.info.len(), 0, "Moniker founded but no moniker expected: {:?}", x);
+            assert_eq!(x.info.len(), 0, "Moniker founded but no moniker expected: {x:?}");
         }
     }
 

crates/ide/src/navigation_target.rs

@@ -117,10 +117,10 @@ impl NavigationTarget {
             self.full_range
         );
         if let Some(focus_range) = self.focus_range {
-            buf.push_str(&format!(" {:?}", focus_range))
+            buf.push_str(&format!(" {focus_range:?}"))
         }
         if let Some(container_name) = &self.container_name {
-            buf.push_str(&format!(" {}", container_name))
+            buf.push_str(&format!(" {container_name}"))
         }
         buf
     }

crates/ide/src/rename.rs

@@ -345,7 +345,7 @@ mod tests {
         let (analysis, position) = fixture::position(ra_fixture_before);
         let rename_result = analysis
             .rename(position, new_name)
-            .unwrap_or_else(|err| panic!("Rename to '{}' was cancelled: {}", new_name, err));
+            .unwrap_or_else(|err| panic!("Rename to '{new_name}' was cancelled: {err}"));
         match rename_result {
             Ok(source_change) => {
                 let mut text_edit_builder = TextEdit::builder();
@@ -371,7 +371,7 @@ mod tests {
                         .collect::<String>();
                     assert_eq!(error_message.trim(), err.to_string());
                 } else {
-                    panic!("Rename to '{}' failed unexpectedly: {}", new_name, err)
+                    panic!("Rename to '{new_name}' failed unexpectedly: {err}")
                 }
             }
         };
@@ -397,11 +397,11 @@ mod tests {
         let (analysis, position) = fixture::position(ra_fixture);
         let result = analysis
             .prepare_rename(position)
-            .unwrap_or_else(|err| panic!("PrepareRename was cancelled: {}", err));
+            .unwrap_or_else(|err| panic!("PrepareRename was cancelled: {err}"));
         match result {
             Ok(RangeInfo { range, info: () }) => {
                 let source = analysis.file_text(position.file_id).unwrap();
-                expect.assert_eq(&format!("{:?}: {}", range, &source[range]))
+                expect.assert_eq(&format!("{range:?}: {}", &source[range]))
             }
             Err(RenameError(err)) => expect.assert_eq(&err),
         };

crates/ide/src/runnables.rs

@@ -66,12 +66,12 @@ impl Runnable {
     // test package::module::testname
     pub fn label(&self, target: Option<String>) -> String {
         match &self.kind {
-            RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
-            RunnableKind::TestMod { path } => format!("test-mod {}", path),
-            RunnableKind::Bench { test_id } => format!("bench {}", test_id),
-            RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
+            RunnableKind::Test { test_id, .. } => format!("test {test_id}"),
+            RunnableKind::TestMod { path } => format!("test-mod {path}"),
+            RunnableKind::Bench { test_id } => format!("bench {test_id}"),
+            RunnableKind::DocTest { test_id, .. } => format!("doctest {test_id}"),
             RunnableKind::Bin => {
-                target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
+                target.map_or_else(|| "run binary".to_string(), |t| format!("run {t}"))
             }
         }
     }
@@ -377,7 +377,7 @@ pub(crate) fn runnable_impl(
     } else {
         String::new()
     };
-    let mut test_id = format!("{}{}", adt_name, params);
+    let mut test_id = format!("{adt_name}{params}");
     test_id.retain(|c| c != ' ');
     let test_id = TestId::Path(test_id);