3 files changed, 80 insertions, 6 deletions

diff --git a/crates/ide_completion/src/completions/flyimport.rs b/crates/ide_completion/src/completions/flyimport.rs
index eb2cba631..1ad017198 100644
--- a/crates/ide_completion/src/completions/flyimport.rs
+++ b/crates/ide_completion/src/completions/flyimport.rs
@@ -1,8 +1,10 @@
 //! Feature: completion with imports-on-the-fly
 //!
 //! When completing names in the current scope, proposes additional imports from other modules or crates,
-//! if they can be qualified in the scope and their name contains all symbols from the completion input
-//! (case-insensitive, in any order or places).
+//! if they can be qualified in the scope and their name contains all symbols from the completion input.
+//!
+//! To be considered applicable, the name must contain all input symbols in the given order, not necessarily adjacent.
+//! If any input symbol is not lowercased, the name must contain all symbols in exact case; otherwise the contaning is checked case-insensitively.
 //!
 //! ```
 //! fn main() {
@@ -942,7 +944,7 @@ mod foo {
 }
 
 fn main() {
-    bar::Ass$0
+    bar::ASS$0
 }"#,
             expect![[]],
         )
@@ -979,4 +981,57 @@ fn main() {
             expect![[]],
         )
     }
+
+    #[test]
+    fn case_matters() {
+        check(
+            r#"
+mod foo {
+    pub const TEST_CONST: usize = 3;
+    pub fn test_function() -> i32 {
+        4
+    }
+}
+
+fn main() {
+    TE$0
+}"#,
+            expect![[r#"
+        ct foo::TEST_CONST
+    "#]],
+        );
+
+        check(
+            r#"
+mod foo {
+    pub const TEST_CONST: usize = 3;
+    pub fn test_function() -> i32 {
+        4
+    }
+}
+
+fn main() {
+    te$0
+}"#,
+            expect![[r#"
+        ct foo::TEST_CONST
+        fn test_function() (foo::test_function) fn() -> i32
+    "#]],
+        );
+
+        check(
+            r#"
+mod foo {
+    pub const TEST_CONST: usize = 3;
+    pub fn test_function() -> i32 {
+        4
+    }
+}
+
+fn main() {
+    Te$0
+}"#,
+            expect![[]],
+        );
+    }
 }
diff --git a/crates/ide_db/src/items_locator.rs b/crates/ide_db/src/items_locator.rs
index 518cddd74..b9d5852e2 100644
--- a/crates/ide_db/src/items_locator.rs
+++ b/crates/ide_db/src/items_locator.rs
@@ -62,6 +62,8 @@ pub fn items_with_name(
             (local_query, external_query)
         }
         NameToImport::Fuzzy(fuzzy_search_string) => {
+            let mut local_query = symbol_index::Query::new(fuzzy_search_string.clone());
+
             let mut external_query = import_map::Query::new(fuzzy_search_string.clone())
                 .search_mode(import_map::SearchMode::Fuzzy)
                 .name_only();
@@ -75,7 +77,12 @@ pub fn items_with_name(
                 }
             }
 
-            (symbol_index::Query::new(fuzzy_search_string), external_query)
+            if fuzzy_search_string.to_lowercase() != fuzzy_search_string {
+                local_query.case_sensitive();
+                external_query = external_query.case_sensitive();
+            }
+
+            (local_query, external_query)
         }
     };
 
diff --git a/crates/ide_db/src/symbol_index.rs b/crates/ide_db/src/symbol_index.rs
index 9ed9568ce..35e382b5c 100644
--- a/crates/ide_db/src/symbol_index.rs
+++ b/crates/ide_db/src/symbol_index.rs
@@ -52,6 +52,7 @@ pub struct Query {
     only_types: bool,
     libs: bool,
     exact: bool,
+    case_sensitive: bool,
     limit: usize,
 }
 
@@ -64,6 +65,7 @@ impl Query {
             only_types: false,
             libs: false,
             exact: false,
+            case_sensitive: false,
             limit: usize::max_value(),
         }
     }
@@ -80,6 +82,10 @@ impl Query {
         self.exact = true;
     }
 
+    pub fn case_sensitive(&mut self) {
+        self.case_sensitive = true;
+    }
+
     pub fn limit(&mut self, limit: usize) {
         self.limit = limit
     }
@@ -326,8 +332,14 @@ impl Query {
                     if self.only_types && !symbol.kind.is_type() {
                         continue;
                     }
-                    if self.exact && symbol.name != self.query {
-                        continue;
+                    if self.exact {
+                        if symbol.name != self.query {
+                            continue;
+                        }
+                    } else if self.case_sensitive {
+                        if self.query.chars().any(|c| !symbol.name.contains(c)) {
+                            continue;
+                        }
                     }
 
                     res.push(symbol.clone());