Merge #4851

4851: Add quickfix to add a struct field r=TimoFreiberg a=TimoFreiberg

Related to #4563 
I created a quickfix for record literals first because the NoSuchField diagnostic was already there.
To offer that quickfix for FieldExprs with unknown fields I'd need to add a new diagnostic (or create a `NoSuchField` diagnostic for those cases)

I think it'd make sense to make this a snippet completion (to select the generated type), but this would require changing the `Analysis` API and I'd like some feedback before I touch that.

Co-authored-by: Timo Freiberg <[email protected]>

2 files changed, 23 insertions, 2 deletions

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index a232a5856..6a49c424a 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -6,9 +6,9 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use hir_def::{
     resolver::{self, HasResolver, Resolver},
-    AsMacroCall, TraitId,
+    AsMacroCall, TraitId, VariantId,
 };
-use hir_expand::{hygiene::Hygiene, ExpansionInfo};
+use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
 use itertools::Itertools;
 use ra_db::{FileId, FileRange};
@@ -104,6 +104,13 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         tree
     }
 
+    pub fn ast<T: AstDiagnostic + Diagnostic>(&self, d: &T) -> <T as AstDiagnostic>::AST {
+        let file_id = d.source().file_id;
+        let root = self.db.parse_or_expand(file_id).unwrap();
+        self.cache(root, file_id);
+        d.ast(self.db)
+    }
+
     pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
         let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
@@ -247,6 +254,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.analyze(path.syntax()).resolve_path(self.db, path)
     }
 
+    pub fn resolve_variant(&self, record_lit: ast::RecordLit) -> Option<VariantId> {
+        self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
+    }
+
     pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
         let src = self.find_file(path.syntax().clone());
         Path::from_src(path.clone(), &Hygiene::new(self.db.upcast(), src.file_id.into()))
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index 7c6bbea13..757d1e397 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -313,6 +313,16 @@ impl SourceAnalyzer {
         })?;
         Some(macro_call_id.as_file())
     }
+
+    pub(crate) fn resolve_variant(
+        &self,
+        db: &dyn HirDatabase,
+        record_lit: ast::RecordLit,
+    ) -> Option<VariantId> {
+        let infer = self.infer.as_ref()?;
+        let expr_id = self.expr_id(db, &record_lit.into())?;
+        infer.variant_resolution_for_expr(expr_id)
+    }
 }
 
 fn scope_for(