fix(engine): correct default regex flag

Author: antfu

.gitignore

@@ -16,3 +16,4 @@ packages/shiki/src/assets/*.json
 cache
 .eslintcache
 report-engine-js-compat.json
+scripts/compares

packages/core/src/engines/javascript.ts

@@ -27,7 +27,7 @@ export class JavaScriptScanner implements PatternScanner {
           p
             // YAML specific handling; TODO: move to tm-grammars
             .replaceAll('[^\\s[-?:,\\[\\]{}#&*!|>\'"%@`]]', '[^\\s\\-?:,\\[\\]{}#&*!|>\'"%@`]'),
-          { flags: 'dg' },
+          { flags: 'dgm' },
         )
         cache?.set(p, regex)
         return regex

packages/shiki/test/engine-js/compare.test.ts

@@ -69,6 +69,14 @@ const cases: Cases[] = [
       'const foo: string = "bar"',
     ],
   },
+  {
+    name: 'jsonc',
+    theme: () => import('../../src/assets/themes/nord'),
+    lang: () => import('../../src/assets/langs/jsonc'),
+    cases: [
+      '// comment\n{"foo":"bar"}',
+    ],
+  },
 ]
 
 describe('cases', async () => {