diff --git a/test/kernel/src/syntax/language_map_test.dart b/test/kernel/src/syntax/language_map_test.dart
new file mode 100644
index 00000000..e88064d7
--- /dev/null
+++ b/test/kernel/src/syntax/language_map_test.dart
@@ -0,0 +1,48 @@
+/// Pure-Dart tests for `grammarForPath` in
+/// `lib/kernel/src/syntax/language_map.dart`.
+library;
+
+import 'package:clide/kernel/src/syntax/language_map.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('grammarForPath', () {
+    test('maps common file extensions to grammar names', () {
+      expect(grammarForPath('foo.dart'), 'dart');
+      expect(grammarForPath('a/b/c.go'), 'go');
+      expect(grammarForPath('script.py'), 'python');
+      expect(grammarForPath('view.tsx'), 'typescript');
+      expect(grammarForPath('config.yaml'), 'yaml');
+      expect(grammarForPath('config.yml'), 'yaml');
+      expect(grammarForPath('readme.md'), 'markdown');
+    });
+
+    test('extension match is case-insensitive', () {
+      expect(grammarForPath('a.R'), 'r');
+      expect(grammarForPath('Q.PY'), 'python');
+    });
+
+    test('special filenames bypass the extension lookup', () {
+      expect(grammarForPath('Makefile'), 'make');
+      expect(grammarForPath('a/b/Dockerfile'), 'dockerfile');
+      expect(grammarForPath('.gitignore'), 'gitignore');
+      expect(grammarForPath('justfile'), 'just');
+    });
+
+    test('special filename + recognised extension still picks the special name', () {
+      // Makefile has no '.' so the extension branch wouldn't fire anyway —
+      // this just locks in that the filename map runs first.
+      expect(grammarForPath('Makefile'), 'make');
+    });
+
+    test('returns null when there is no dot and no special filename match', () {
+      expect(grammarForPath('README'), isNull);
+      expect(grammarForPath('a/b/UNKNOWNFILE'), isNull);
+    });
+
+    test('returns null for an unknown extension', () {
+      expect(grammarForPath('foo.unknownextension'), isNull);
+      expect(grammarForPath('a/b/c.xyz'), isNull);
+    });
+  });
+}
diff --git a/test/kernel/src/syntax/tree_sitter_service_test.dart b/test/kernel/src/syntax/tree_sitter_service_test.dart
new file mode 100644
index 00000000..c917f864
--- /dev/null
+++ b/test/kernel/src/syntax/tree_sitter_service_test.dart
@@ -0,0 +1,66 @@
+/// Tests the graceful-fallback paths of `TreeSitterService` when the
+/// native `libtree-sitter` library isn't dlopen-resolvable. In that
+/// environment the service short-circuits every public method without
+/// throwing — which is also how the running app behaves on platforms
+/// where the library hasn't been bundled.
+library;
+
+import 'package:clide/kernel/src/syntax/tree_sitter_service.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  group('TreeSitterService — fallback paths', () {
+    final svc = TreeSitterService.shared;
+
+    test('hasGrammar(path) returns false for an unknown extension', () async {
+      expect(await svc.hasGrammar('foo.unknownextension'), isFalse);
+    });
+
+    test('hasGrammar(path) returns false when the library cannot load', () async {
+      // 'foo.dart' resolves to grammar "dart", which still requires the
+      // native library + asset to actually load. In the test runner the
+      // native lib isn't on the dlopen search path, so _init() fails and
+      // hasGrammar reports false.
+      expect(await svc.hasGrammar('foo.dart'), isFalse);
+    });
+
+    test('languageFor(path) returns null when the language is unknown', () async {
+      expect(await svc.languageFor('foo.unknownextension'), isNull);
+    });
+
+    test('languageFor(path) returns null when the library cannot load', () async {
+      expect(await svc.languageFor('foo.dart'), isNull);
+    });
+
+    test('highlight returns an empty result for unknown extensions', () async {
+      final r = await svc.highlight('foo.unknownextension', 'whatever');
+      expect(r.spans, isEmpty);
+    });
+
+    test('highlight returns an empty result when the library cannot load', () async {
+      final r = await svc.highlight('foo.dart', 'void main() {}');
+      expect(r.spans, isEmpty);
+    });
+
+    test('loadedLanguages getter returns a list (may be empty)', () {
+      // Just exercise the getter — the actual contents depend on the
+      // environment.
+      expect(svc.loadedLanguages, isA<List<String>>());
+    });
+  });
+
+  group('SyntaxResult / SyntaxSpan', () {
+    test('SyntaxResult.empty has no spans', () {
+      expect(SyntaxResult.empty.spans, isEmpty);
+    });
+
+    test('SyntaxSpan stores start / end / role', () {
+      const s = SyntaxSpan(start: 3, end: 7, role: 'keyword');
+      expect(s.start, 3);
+      expect(s.end, 7);
+      expect(s.role, 'keyword');
+    });
+  });
+}