3 files changed, 39 insertions, 1 deletions

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 3ad30f0c9..b2714cb69 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -895,4 +895,17 @@ impl TestStruct {
 "#,
         );
     }
+
+    #[test]
+    fn test_single_incorrect_case_diagnostic_in_function_name_issue_6970() {
+        let input = r#"fn FOO<|>() {}"#;
+        let expected = r#"fn foo() {}"#;
+
+        let (analysis, file_position) = fixture::position(input);
+        let diagnostics =
+            analysis.diagnostics(&DiagnosticsConfig::default(), file_position.file_id).unwrap();
+        assert_eq!(diagnostics.len(), 1);
+
+        check_fixes(input, expected);
+    }
 }
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index dbad9a84f..52c7f9775 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -535,6 +535,14 @@ impl Analysis {
         self.with_db(|db| references::rename::prepare_rename(db, position))
     }
 
+    pub fn will_rename_file(
+        &self,
+        file_id: FileId,
+        new_name_stem: &str,
+    ) -> Cancelable<Option<SourceChange>> {
+        self.with_db(|db| references::rename::will_rename_file(db, file_id, new_name_stem))
+    }
+
     pub fn structural_search_replace(
         &self,
         query: &str,
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index cd721b7eb..15c95f239 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -6,7 +6,7 @@ use std::{
 };
 
 use hir::{Module, ModuleDef, ModuleSource, Semantics};
-use ide_db::base_db::{AnchoredPathBuf, FileRange, SourceDatabaseExt};
+use ide_db::base_db::{AnchoredPathBuf, FileId, FileRange, SourceDatabaseExt};
 use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
@@ -110,6 +110,23 @@ pub(crate) fn rename_with_semantics(
     }
 }
 
+pub(crate) fn will_rename_file(
+    db: &RootDatabase,
+    file_id: FileId,
+    new_name_stem: &str,
+) -> Option<SourceChange> {
+    let sema = Semantics::new(db);
+    let module = sema.to_module_def(file_id)?;
+
+    let decl = module.declaration_source(db)?;
+    let range = decl.value.name()?.syntax().text_range();
+
+    let position = FilePosition { file_id: decl.file_id.original_file(db), offset: range.start() };
+    let mut change = rename_mod(&sema, position, module, new_name_stem).ok()?.info;
+    change.file_system_edits.clear();
+    Some(change)
+}
+
 fn find_module_at_offset(
     sema: &Semantics<RootDatabase>,
     position: FilePosition,