Add support for Glimmer JS and Glimmer TS

languages.json

@@ -545,6 +545,20 @@
       "quotes": [["\\\"", "\\\""]],
       "extensions": ["gleam"]
     },
+    "GlimmerJs": {
+      "name": "Glimmer JS",
+      "multi_line_comments": [["<!--", "-->"], ["{{!", "}}"], ["/*", "*/"]],
+      "quotes": [["\\\"", "\\\""], ["'", "'"], ["`", "`"]],
+      "extensions": ["gjs"],
+      "line_comment": ["//"]
+    },
+    "GlimmerTs": {
+      "name": "Glimmer TS",
+      "multi_line_comments": [["<!--", "-->"], ["{{!", "}}"], ["/*", "*/"]],
+      "quotes": [["\\\"", "\\\""], ["'", "'"], ["`", "`"]],
+      "extensions": ["gts"],
+      "line_comment": ["//"]
+    },
     "Glsl": {
       "name": "GLSL",
       "line_comment": ["//"],

tests/data/glimmer_js.gjs

@@ -0,0 +1,29 @@
+// 29 lines 17 code 6 comments 5 blanks
+
+import Component from '@glimmer/component';
+
+/** 
+ * @param bar - a thing
+ */
+function foo(bar) {
+  console.log(bar); // we foo'd the bar
+}
+
+const Greet = <template>
+  {{! a Handlebars comment in the template }}
+  <div>A template!</div>
+  <!-- an HTML comment in the template -->
+  <p>{{@greeting}}</p>
+</template>;
+
+class Example extends Component {
+  get greeting() {
+    // counts
+    return `Hello, ${this.args.name}`; // does not count
+  }
+
+  <template>
+    <Greet @greeting={{this.greeting}} /> {{! with an HBS comment }}
+    <div>{{yield @extra}}</div> <!-- with an HTML comment -->
+  </template>
+}

tests/data/glimmer_ts.gts

@@ -0,0 +1,47 @@
+// 47 lines 31 code 9 comments 6 blanks
+
+import Component from '@glimmer/component';
+import type { TOC } from '@ember/component/template-only';
+
+/** 
+ * @param bar - a thing
+ */
+function foo(bar: string): void {
+  console.log(bar); // we foo'd the bar
+}
+
+const Greet: TOC<{
+  Args: {
+    /** the greeting to show */
+    greeting: string;
+  };
+}> = <template>
+  {{! a Handlebars comment in the template }}
+  <div>A template!</div>
+  <!-- an HTML comment in the template -->
+  <p>{{@greeting}}</p>
+</template>;
+
+interface ExampleSig<T> {
+  Args: {
+    /** The name of the person to greet */
+    name: string;
+    /** Extra info to pass along */
+    extra: T;
+  };
+  Blocks: {
+    default: [T];
+  };
+}
+
+class Example extends Component<CommonSig> {
+  get greeting() {
+    // counts
+    return `Hello, ${this.args.name}`; // does not count
+  }
+
+  <template>
+    <Greet @greeting={{this.greeting}} /> {{! with an HBS comment }}
+    <div>{{yield @extra}}</div> <!-- with an HTML comment -->
+  </template>
+}