Auto merge of #9479 - kraktus:manual_assert2, r=llogiq

[`manual_assert`]: Preserve comments in the suggestion

close https://github.com/rust-lang/rust-clippy/issues/7730

changelog: [`manual_assert`]: Preserve comments in the suggestion

clippy_lints/src/manual_assert.rs

@@ -1,7 +1,8 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use crate::rustc_lint::LintContext;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::macros::{root_macro_call, FormatArgsExpn};
 use clippy_utils::source::snippet_with_applicability;
-use clippy_utils::{peel_blocks_with_stmt, sugg};
+use clippy_utils::{peel_blocks_with_stmt, span_extract_comment, sugg};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
@@ -50,20 +51,36 @@ impl<'tcx> LateLintPass<'tcx> for ManualAssert {
                 let mut applicability = Applicability::MachineApplicable;
                 let format_args_snip = snippet_with_applicability(cx, format_args.inputs_span(), "..", &mut applicability);
                 let cond = cond.peel_drop_temps();
+                let mut comments = span_extract_comment(cx.sess().source_map(), expr.span);
+                if !comments.is_empty() {
+                    comments += "\n";
+                }
                 let (cond, not) = match cond.kind {
                     ExprKind::Unary(UnOp::Not, e) => (e, ""),
                     _ => (cond, "!"),
                 };
                 let cond_sugg = sugg::Sugg::hir_with_applicability(cx, cond, "..", &mut applicability).maybe_par();
                 let sugg = format!("assert!({not}{cond_sugg}, {format_args_snip});");
-                span_lint_and_sugg(
+                // we show to the user the suggestion without the comments, but when applicating the fix, include the comments in the block
+                span_lint_and_then(
                     cx,
                     MANUAL_ASSERT,
                     expr.span,
                     "only a `panic!` in `if`-then statement",
-                    "try",
+                    |diag| {
+                        // comments can be noisy, do not show them to the user
+                        diag.tool_only_span_suggestion(
+                                    expr.span.shrink_to_lo(),
+                                    "add comments back",
+                                    comments,
+                                    applicability);
+                        diag.span_suggestion(
+                                    expr.span,
+                                    "try instead",
                                     sugg,
-                    Applicability::MachineApplicable,
+                                    applicability);
+                                     }
+
                 );
             }
         }

clippy_utils/src/lib.rs

@@ -2295,6 +2295,29 @@ pub fn span_contains_comment(sm: &SourceMap, span: Span) -> bool {
     });
 }
 
+/// Return all the comments a given span contains
+/// Comments are returned wrapped with their relevant delimiters
+pub fn span_extract_comment(sm: &SourceMap, span: Span) -> String {
+    let snippet = sm.span_to_snippet(span).unwrap_or_default();
+    let mut comments_buf: Vec<String> = Vec::new();
+    let mut index: usize = 0;
+
+    for token in tokenize(&snippet) {
+        let token_range = index..(index + token.len as usize);
+        index += token.len as usize;
+        match token.kind {
+            TokenKind::BlockComment { .. } | TokenKind::LineComment { .. } => {
+                if let Some(comment) = snippet.get(token_range) {
+                    comments_buf.push(comment.to_string());
+                }
+            },
+            _ => (),
+        }
+    }
+
+    comments_buf.join("\n")
+}
+
 macro_rules! op_utils {
     ($($name:ident $assign:ident)*) => {
         /// Binary operation traits like `LangItem::Add`

tests/ui/manual_assert.edition2018.fixed

@@ -4,7 +4,7 @@
 // run-rustfix
 
 #![warn(clippy::manual_assert)]
-#![allow(clippy::nonminimal_bool)]
+#![allow(dead_code, unused_doc_comments, clippy::nonminimal_bool)]
 
 macro_rules! one {
     () => {
@@ -50,3 +50,14 @@ fn main() {
     assert!(!(a.is_empty() || !b.is_empty()), "panic5");
     assert!(!a.is_empty(), "with expansion {}", one!());
 }
+
+fn issue7730(a: u8) {
+    // Suggestion should preserve comment
+    // comment
+/* this is a
+        multiline
+        comment */
+/// Doc comment
+// comment after `panic!`
+assert!(!(a > 2), "panic with comment");
+}

tests/ui/manual_assert.edition2018.stderr

@@ -4,9 +4,13 @@ error: only a `panic!` in `if`-then statement
 LL | /     if !a.is_empty() {
 LL | |         panic!("qaqaq{:?}", a);
 LL | |     }
-   | |_____^ help: try: `assert!(a.is_empty(), "qaqaq{:?}", a);`
+   | |_____^
    |
    = note: `-D clippy::manual-assert` implied by `-D warnings`
+help: try instead
+   |
+LL |     assert!(a.is_empty(), "qaqaq{:?}", a);
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:33:5
@@ -14,7 +18,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if !a.is_empty() {
 LL | |         panic!("qwqwq");
 LL | |     }
-   | |_____^ help: try: `assert!(a.is_empty(), "qwqwq");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(a.is_empty(), "qwqwq");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:50:5
@@ -22,7 +31,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() {
 LL | |         panic!("panic1");
 LL | |     }
-   | |_____^ help: try: `assert!(!b.is_empty(), "panic1");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!b.is_empty(), "panic1");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:53:5
@@ -30,7 +44,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() && a.is_empty() {
 LL | |         panic!("panic2");
 LL | |     }
-   | |_____^ help: try: `assert!(!(b.is_empty() && a.is_empty()), "panic2");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(b.is_empty() && a.is_empty()), "panic2");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:56:5
@@ -38,7 +57,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() && !b.is_empty() {
 LL | |         panic!("panic3");
 LL | |     }
-   | |_____^ help: try: `assert!(!(a.is_empty() && !b.is_empty()), "panic3");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a.is_empty() && !b.is_empty()), "panic3");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:59:5
@@ -46,7 +70,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() || a.is_empty() {
 LL | |         panic!("panic4");
 LL | |     }
-   | |_____^ help: try: `assert!(!(b.is_empty() || a.is_empty()), "panic4");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(b.is_empty() || a.is_empty()), "panic4");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:62:5
@@ -54,7 +83,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() || !b.is_empty() {
 LL | |         panic!("panic5");
 LL | |     }
-   | |_____^ help: try: `assert!(!(a.is_empty() || !b.is_empty()), "panic5");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a.is_empty() || !b.is_empty()), "panic5");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:65:5
@@ -62,7 +96,29 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() {
 LL | |         panic!("with expansion {}", one!())
 LL | |     }
-   | |_____^ help: try: `assert!(!a.is_empty(), "with expansion {}", one!());`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!a.is_empty(), "with expansion {}", one!());
+   |
 
-error: aborting due to 8 previous errors
+error: only a `panic!` in `if`-then statement
+  --> $DIR/manual_assert.rs:72:5
+   |
+LL | /     if a > 2 {
+LL | |         // comment
+LL | |         /* this is a
+LL | |         multiline
+...  |
+LL | |         panic!("panic with comment") // comment after `panic!`
+LL | |     }
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a > 2), "panic with comment");
+   |
+
+error: aborting due to 9 previous errors
 

tests/ui/manual_assert.edition2021.fixed

@@ -4,7 +4,7 @@
 // run-rustfix
 
 #![warn(clippy::manual_assert)]
-#![allow(clippy::nonminimal_bool)]
+#![allow(dead_code, unused_doc_comments, clippy::nonminimal_bool)]
 
 macro_rules! one {
     () => {
@@ -50,3 +50,14 @@ fn main() {
     assert!(!(a.is_empty() || !b.is_empty()), "panic5");
     assert!(!a.is_empty(), "with expansion {}", one!());
 }
+
+fn issue7730(a: u8) {
+    // Suggestion should preserve comment
+    // comment
+/* this is a
+        multiline
+        comment */
+/// Doc comment
+// comment after `panic!`
+assert!(!(a > 2), "panic with comment");
+}

tests/ui/manual_assert.edition2021.stderr

@@ -4,9 +4,13 @@ error: only a `panic!` in `if`-then statement
 LL | /     if !a.is_empty() {
 LL | |         panic!("qaqaq{:?}", a);
 LL | |     }
-   | |_____^ help: try: `assert!(a.is_empty(), "qaqaq{:?}", a);`
+   | |_____^
    |
    = note: `-D clippy::manual-assert` implied by `-D warnings`
+help: try instead
+   |
+LL |     assert!(a.is_empty(), "qaqaq{:?}", a);
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:33:5
@@ -14,7 +18,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if !a.is_empty() {
 LL | |         panic!("qwqwq");
 LL | |     }
-   | |_____^ help: try: `assert!(a.is_empty(), "qwqwq");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(a.is_empty(), "qwqwq");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:50:5
@@ -22,7 +31,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() {
 LL | |         panic!("panic1");
 LL | |     }
-   | |_____^ help: try: `assert!(!b.is_empty(), "panic1");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!b.is_empty(), "panic1");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:53:5
@@ -30,7 +44,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() && a.is_empty() {
 LL | |         panic!("panic2");
 LL | |     }
-   | |_____^ help: try: `assert!(!(b.is_empty() && a.is_empty()), "panic2");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(b.is_empty() && a.is_empty()), "panic2");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:56:5
@@ -38,7 +57,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() && !b.is_empty() {
 LL | |         panic!("panic3");
 LL | |     }
-   | |_____^ help: try: `assert!(!(a.is_empty() && !b.is_empty()), "panic3");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a.is_empty() && !b.is_empty()), "panic3");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:59:5
@@ -46,7 +70,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if b.is_empty() || a.is_empty() {
 LL | |         panic!("panic4");
 LL | |     }
-   | |_____^ help: try: `assert!(!(b.is_empty() || a.is_empty()), "panic4");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(b.is_empty() || a.is_empty()), "panic4");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:62:5
@@ -54,7 +83,12 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() || !b.is_empty() {
 LL | |         panic!("panic5");
 LL | |     }
-   | |_____^ help: try: `assert!(!(a.is_empty() || !b.is_empty()), "panic5");`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a.is_empty() || !b.is_empty()), "panic5");
+   |
 
 error: only a `panic!` in `if`-then statement
   --> $DIR/manual_assert.rs:65:5
@@ -62,7 +96,29 @@ error: only a `panic!` in `if`-then statement
 LL | /     if a.is_empty() {
 LL | |         panic!("with expansion {}", one!())
 LL | |     }
-   | |_____^ help: try: `assert!(!a.is_empty(), "with expansion {}", one!());`
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!a.is_empty(), "with expansion {}", one!());
+   |
 
-error: aborting due to 8 previous errors
+error: only a `panic!` in `if`-then statement
+  --> $DIR/manual_assert.rs:72:5
+   |
+LL | /     if a > 2 {
+LL | |         // comment
+LL | |         /* this is a
+LL | |         multiline
+...  |
+LL | |         panic!("panic with comment") // comment after `panic!`
+LL | |     }
+   | |_____^
+   |
+help: try instead
+   |
+LL |     assert!(!(a > 2), "panic with comment");
+   |
+
+error: aborting due to 9 previous errors
 

tests/ui/manual_assert.rs

@@ -4,7 +4,7 @@
 // run-rustfix
 
 #![warn(clippy::manual_assert)]
-#![allow(clippy::nonminimal_bool)]
+#![allow(dead_code, unused_doc_comments, clippy::nonminimal_bool)]
 
 macro_rules! one {
     () => {
@@ -66,3 +66,15 @@ fn main() {
         panic!("with expansion {}", one!())
     }
 }
+
+fn issue7730(a: u8) {
+    // Suggestion should preserve comment
+    if a > 2 {
+        // comment
+        /* this is a
+        multiline
+        comment */
+        /// Doc comment
+        panic!("panic with comment") // comment after `panic!`
+    }
+}