Auto merge of rust-lang#8028 - dswij:8016, r=flip1995

Add more descriptive help info for `needless_question_mark`

closes rust-lang#8016

changelog: [`needless_question_mark`] help suggestion now explains what should be changed

Author: bors

clippy_lints/src/needless_question_mark.rs

@@ -93,26 +93,33 @@ impl LateLintPass<'_> for NeedlessQuestionMark {
 }
 
 fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
-    let inner_expr = if_chain! {
+    if_chain! {
         if let ExprKind::Call(path, [arg]) = &expr.kind;
         if let ExprKind::Path(ref qpath) = &path.kind;
-        if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk);
+        let sugg_remove = if is_lang_ctor(cx, qpath, OptionSome) {
+            "Some()"
+        } else if is_lang_ctor(cx, qpath, ResultOk) {
+            "Ok()"
+        } else {
+            return;
+        };
         if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar) = &arg.kind;
         if let ExprKind::Call(called, [inner_expr]) = &inner_expr_with_q.kind;
         if let ExprKind::Path(QPath::LangItem(LangItem::TryTraitBranch, _)) = &called.kind;
         if expr.span.ctxt() == inner_expr.span.ctxt();
         let expr_ty = cx.typeck_results().expr_ty(expr);
         let inner_ty = cx.typeck_results().expr_ty(inner_expr);
         if TyS::same_type(expr_ty, inner_ty);
-        then { inner_expr } else { return; }
-    };
-    span_lint_and_sugg(
-        cx,
-        NEEDLESS_QUESTION_MARK,
-        expr.span,
-        "question mark operator is useless here",
-        "try",
-        format!("{}", snippet(cx, inner_expr.span, r#""...""#)),
-        Applicability::MachineApplicable,
-    );
+        then {
+            span_lint_and_sugg(
+                cx,
+                NEEDLESS_QUESTION_MARK,
+                expr.span,
+                "question mark operator is useless here",
+                &format!("try removing question mark and `{}`", sugg_remove),
+                format!("{}", snippet(cx, inner_expr.span, r#""...""#)),
+                Applicability::MachineApplicable,
+            );
+        }
+    }
 }

tests/ui/needless_question_mark.stderr

@@ -2,75 +2,75 @@ error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:23:12
    |
 LL |     return Some(to.magic?);
-   |            ^^^^^^^^^^^^^^^ help: try: `to.magic`
+   |            ^^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `to.magic`
    |
    = note: `-D clippy::needless-question-mark` implied by `-D warnings`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:31:12
    |
 LL |     return Some(to.magic?)
-   |            ^^^^^^^^^^^^^^^ help: try: `to.magic`
+   |            ^^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `to.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:36:5
    |
 LL |     Some(to.magic?)
-   |     ^^^^^^^^^^^^^^^ help: try: `to.magic`
+   |     ^^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `to.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:41:21
    |
 LL |     to.and_then(|t| Some(t.magic?))
-   |                     ^^^^^^^^^^^^^^ help: try: `t.magic`
+   |                     ^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `t.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:50:9
    |
 LL |         Some(t.magic?)
-   |         ^^^^^^^^^^^^^^ help: try: `t.magic`
+   |         ^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `t.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:55:12
    |
 LL |     return Ok(tr.magic?);
-   |            ^^^^^^^^^^^^^ help: try: `tr.magic`
+   |            ^^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `tr.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:62:12
    |
 LL |     return Ok(tr.magic?)
-   |            ^^^^^^^^^^^^^ help: try: `tr.magic`
+   |            ^^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `tr.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:66:5
    |
 LL |     Ok(tr.magic?)
-   |     ^^^^^^^^^^^^^ help: try: `tr.magic`
+   |     ^^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `tr.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:70:21
    |
 LL |     tr.and_then(|t| Ok(t.magic?))
-   |                     ^^^^^^^^^^^^ help: try: `t.magic`
+   |                     ^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `t.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:78:9
    |
 LL |         Ok(t.magic?)
-   |         ^^^^^^^^^^^^ help: try: `t.magic`
+   |         ^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `t.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:85:16
    |
 LL |         return Ok(t.magic?);
-   |                ^^^^^^^^^^^^ help: try: `t.magic`
+   |                ^^^^^^^^^^^^ help: try removing question mark and `Ok()`: `t.magic`
 
 error: question mark operator is useless here
   --> $DIR/needless_question_mark.rs:120:27
    |
 LL |         || -> Option<_> { Some(Some($expr)?) }()
-   |                           ^^^^^^^^^^^^^^^^^^ help: try: `Some($expr)`
+   |                           ^^^^^^^^^^^^^^^^^^ help: try removing question mark and `Some()`: `Some($expr)`
 ...
 LL |     let _x = some_and_qmark_in_macro!(x?);
    |              ---------------------------- in this macro invocation