feat: improve name generation in destructure_tuple_binding

crates/ide-assists/src/assist_context.rs

@@ -3,6 +3,7 @@
 use hir::{FileRange, Semantics};
 use ide_db::EditionedFileId;
 use ide_db::{label::Label, FileId, RootDatabase};
+use syntax::Edition;
 use syntax::{
     algo::{self, find_node_at_offset, find_node_at_range},
     AstNode, AstToken, Direction, SourceFile, SyntaxElement, SyntaxKind, SyntaxToken, TextRange,
@@ -94,6 +95,10 @@ impl<'a> AssistContext<'a> {
         self.frange.file_id
     }
 
+    pub(crate) fn edition(&self) -> Edition {
+        self.frange.file_id.edition()
+    }
+
     pub(crate) fn has_empty_selection(&self) -> bool {
         self.trimmed_range.is_empty()
     }

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

@@ -1,10 +1,12 @@
-use ide_db::text_edit::TextRange;
 use ide_db::{
     assists::{AssistId, AssistKind},
     defs::Definition,
     search::{FileReference, SearchScope, UsageSearchResult},
+    syntax_helpers::suggest_name,
+    text_edit::TextRange,
 };
 use itertools::Itertools;
+use syntax::SmolStr;
 use syntax::{
     ast::{self, make, AstNode, FieldExpr, HasName, IdentPat},
     ted,
@@ -131,24 +133,31 @@ fn collect_data(ident_pat: IdentPat, ctx: &AssistContext<'_>) -> Option<TupleDat
             .all()
     });
 
-    let field_names = (0..field_types.len())
-        .map(|i| generate_name(ctx, i, &name, &ident_pat, &usages))
+    let mut name_generator = {
+        let mut names = vec![];
+        ctx.sema.scope(ident_pat.syntax())?.process_all_names(&mut |name, scope| {
+            if let hir::ScopeDef::Local(_) = scope {
+                names.push(name.as_str().into())
+            }
+        });
+        suggest_name::NameGenerator::new_with_names(names.iter().map(|s: &SmolStr| s.as_str()))
+    };
+
+    let field_names = field_types
+        .into_iter()
+        .enumerate()
+        .map(|(id, ty)| {
+            match name_generator.for_type(&ty, ctx.db(), ctx.edition()) {
+                Some(name) => name,
+                None => name_generator.suggest_name(&format!("_{}", id)),
+            }
+            .to_string()
+        })
         .collect::<Vec<_>>();
 
     Some(TupleData { ident_pat, ref_type, field_names, usages })
 }
 
-fn generate_name(
-    _ctx: &AssistContext<'_>,
-    index: usize,
-    _tuple_name: &str,
-    _ident_pat: &IdentPat,
-    _usages: &Option<UsageSearchResult>,
-) -> String {
-    // FIXME: detect if name already used
-    format!("_{index}")
-}
-
 enum RefType {
     ReadOnly,
     Mutable,
@@ -1769,14 +1778,14 @@ struct S4 {
 }
 
 fn foo() -> Option<()> {
-    let ($0_0, _1, _2, _3, _4, _5) = &(0, (1,"1"), Some(2), [3;3], S4 { value: 4 }, &5);
+    let ($0_0, _1, _2, _3, s4, _5) = &(0, (1,"1"), Some(2), [3;3], S4 { value: 4 }, &5);
     let v: i32 = *_0;           // deref, no parens
     let v: &i32 = _0;         // no deref, no parens, remove `&`
     f1(*_0);                    // deref, no parens
     f2(_0);                   // `&*` -> cancel out -> no deref, no parens
     // https://github.com/rust-lang/rust-analyzer/issues/1109#issuecomment-658868639
     // let v: i32 = t.1.0;      // no deref, no parens
-    let v: i32 = _4.value;     // no deref, no parens
+    let v: i32 = s4.value;     // no deref, no parens
     (*_0).do_stuff();             // deref, parens
     let v: i32 = (*_2)?;          // deref, parens
     let v: i32 = _3[0];        // no deref, no parens
@@ -1815,8 +1824,8 @@ impl S {
 }
 
 fn main() {
-    let ($0_0, _1) = &(S,2);
-    let s = _0.f();
+    let ($0s, _1) = &(S,2);
+    let s = s.f();
 }
                 "#,
             )
@@ -1845,8 +1854,8 @@ impl S {
 }
 
 fn main() {
-    let ($0_0, _1) = &(S,2);
-    let s = (*_0).f();
+    let ($0s, _1) = &(S,2);
+    let s = (*s).f();
 }
                 "#,
             )
@@ -1882,8 +1891,8 @@ impl T for &S {
 }
 
 fn main() {
-    let ($0_0, _1) = &(S,2);
-    let s = (*_0).f();
+    let ($0s, _1) = &(S,2);
+    let s = (*s).f();
 }
                 "#,
             )
@@ -1923,8 +1932,8 @@ impl T for &S {
 }
 
 fn main() {
-    let ($0_0, _1) = &(S,2);
-    let s = (*_0).f();
+    let ($0s, _1) = &(S,2);
+    let s = (*s).f();
 }
                 "#,
             )
@@ -1951,8 +1960,8 @@ impl S {
     fn do_stuff(&self) -> i32 { 42 }
 }
 fn main() {
-    let ($0_0, _1) = &(S,&S);
-    let v = _0.do_stuff();
+    let ($0s, s1) = &(S,&S);
+    let v = s.do_stuff();
 }
                 "#,
             )
@@ -1973,7 +1982,7 @@ fn main() {
     // `t.0` gets auto-refed -> no deref needed -> no parens
     let v = t.0.do_stuff();         // no deref, no parens
     let v = &t.0.do_stuff();        // `&` is for result -> no deref, no parens
-    // deref: `_1` is `&&S`, but method called is on `&S` -> there might be a method accepting `&&S`
+    // deref: `s1` is `&&S`, but method called is on `&S` -> there might be a method accepting `&&S`
     let v = t.1.do_stuff();         // deref, parens
 }
                 "#,
@@ -1984,13 +1993,13 @@ impl S {
     fn do_stuff(&self) -> i32 { 42 }
 }
 fn main() {
-    let ($0_0, _1) = &(S,&S);
-    let v = _0.do_stuff();      // no deref, remove parens
+    let ($0s, s1) = &(S,&S);
+    let v = s.do_stuff();      // no deref, remove parens
     // `t.0` gets auto-refed -> no deref needed -> no parens
-    let v = _0.do_stuff();         // no deref, no parens
-    let v = &_0.do_stuff();        // `&` is for result -> no deref, no parens
-    // deref: `_1` is `&&S`, but method called is on `&S` -> there might be a method accepting `&&S`
-    let v = (*_1).do_stuff();         // deref, parens
+    let v = s.do_stuff();         // no deref, no parens
+    let v = &s.do_stuff();        // `&` is for result -> no deref, no parens
+    // deref: `s1` is `&&S`, but method called is on `&S` -> there might be a method accepting `&&S`
+    let v = (*s1).do_stuff();         // deref, parens
 }
                 "#,
             )

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

@@ -377,6 +377,8 @@ fn name_of_type(ty: &hir::Type, db: &RootDatabase, edition: Edition) -> Option<S
             return None;
         }
         name
+    } else if let Some(inner_ty) = ty.remove_ref() {
+        return name_of_type(&inner_ty, db, edition);
     } else {
         return None;
     };