Merge #5553

5553: Add fix ranges for diagnostics r=matklad a=SomeoneToIgnore

A follow-up of https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0/topic/Less.20red.20in.20the.20code

Now diagnostics can apply fixes in a range that's different from the range used to highlight the diagnostics.
Previous logic did not consider the fix range, having both ranges equal, which could cause a lot of red noise in the editor.
Now, the fix range gets used with the fix, the diagnostics range is used for everything else which allows to improve the error highlighting.

before:
<img width="191" alt="image" src="https://user-images.githubusercontent.com/2690773/88590727-df9a6a00-d063-11ea-97ed-9809c1c5e6e6.png">
after:
<img width="222" alt="image" src="https://user-images.githubusercontent.com/2690773/88590734-e1fcc400-d063-11ea-9b7c-25701cbd5352.png">

`MissingFields` and `MissingPatFields` diagnostics now have the fix range as `ast::RecordFieldList` of the expression with an error (as it was before this PR), and the diagnostics range as a `ast::Path` of the expression, if it's present (do you have any example of `ast::Expr::RecordLit` that has no path btw?).
The rest of the diagnostics have both ranges equal, same as it was before this PR.

Co-authored-by: Kirill Bulatov <[email protected]>

2 files changed, 13 insertions, 9 deletions

diff --git a/crates/ra_hir_ty/src/diagnostics/expr.rs b/crates/ra_hir_ty/src/diagnostics/expr.rs
index 95bbf2d95..51adcecaf 100644
--- a/crates/ra_hir_ty/src/diagnostics/expr.rs
+++ b/crates/ra_hir_ty/src/diagnostics/expr.rs
@@ -100,8 +100,8 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
 
         if let Ok(source_ptr) = source_map.expr_syntax(id) {
             let root = source_ptr.file_syntax(db.upcast());
-            if let ast::Expr::RecordExpr(record_lit) = &source_ptr.value.to_node(&root) {
-                if let Some(field_list) = record_lit.record_expr_field_list() {
+            if let ast::Expr::RecordExpr(record_expr) = &source_ptr.value.to_node(&root) {
+                if let Some(_) = record_expr.record_expr_field_list() {
                     let variant_data = variant_data(db.upcast(), variant_def);
                     let missed_fields = missed_fields
                         .into_iter()
@@ -109,7 +109,8 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                         .collect();
                     self.sink.push(MissingFields {
                         file: source_ptr.file_id,
-                        field_list: AstPtr::new(&field_list),
+                        field_list_parent: AstPtr::new(&record_expr),
+                        field_list_parent_path: record_expr.path().map(|path| AstPtr::new(&path)),
                         missed_fields,
                     })
                 }
@@ -131,7 +132,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             if let Some(expr) = source_ptr.value.as_ref().left() {
                 let root = source_ptr.file_syntax(db.upcast());
                 if let ast::Pat::RecordPat(record_pat) = expr.to_node(&root) {
-                    if let Some(field_list) = record_pat.record_pat_field_list() {
+                    if let Some(_) = record_pat.record_pat_field_list() {
                         let variant_data = variant_data(db.upcast(), variant_def);
                         let missed_fields = missed_fields
                             .into_iter()
@@ -139,7 +140,10 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                             .collect();
                         self.sink.push(MissingPatFields {
                             file: source_ptr.file_id,
-                            field_list: AstPtr::new(&field_list),
+                            field_list_parent: AstPtr::new(&record_pat),
+                            field_list_parent_path: record_pat
+                                .path()
+                                .map(|path| AstPtr::new(&path)),
                             missed_fields,
                         })
                     }
diff --git a/crates/ra_hir_ty/src/diagnostics/match_check.rs b/crates/ra_hir_ty/src/diagnostics/match_check.rs
index 507edcb7d..deca244db 100644
--- a/crates/ra_hir_ty/src/diagnostics/match_check.rs
+++ b/crates/ra_hir_ty/src/diagnostics/match_check.rs
@@ -1161,15 +1161,15 @@ fn main() {
         //^ Missing match arm
     match a {
         Either::A { } => (),
-                //^^^ Missing structure fields:
-                //  | - foo
+      //^^^^^^^^^ Missing structure fields:
+      //        | - foo
         Either::B => (),
     }
     match a {
         //^ Missing match arm
         Either::A { } => (),
-    }           //^^^ Missing structure fields:
-                //  | - foo
+    } //^^^^^^^^^ Missing structure fields:
+      //        | - foo
 
     match a {
         Either::A { foo: true } => (),