[gjs] Fix bug with regex issues when parsing GLIMMER_TEMPLATE (#1793)

* failing test case for regex issues when parsing GLIMMER_TEMPLATE

* update test assertion to be correct once fix is applied

* fix test by properly escaping text before constructing regex

* rename test

---------

Co-authored-by: Henry Majoros <hmajoros@linkedin.com>

Author: hmajoros

lib/preprocessors/glimmer.js

@@ -9,6 +9,11 @@ const util = require('ember-template-imports/src/util');
 const TRANSFORM_CACHE = new Map();
 const TEXT_CACHE = new Map();
 
+// source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#escaping
+function escapeRegExp(string) {
+  return string.replace(/[$()*+.?[\\\]^{|}]/g, '\\$&'); // $& means the whole matched string
+}
+
 /**
  * This function is responsible for running the embedded templates transform
  * from ember-template-imports.
@@ -122,7 +127,7 @@ function mapRange(messages, filename) {
     let originalColumnNumber = 0;
 
     for (const [index, line] of originalLines.entries()) {
-      const column = line.search(new RegExp(`\\b${token}\\b`));
+      const column = line.search(new RegExp(`\\b${escapeRegExp(token)}\\b`));
       if (column > -1) {
         originalLineNumber = index + 1;
         originalColumnNumber = column + 1;

tests/lib/rules-preprocessor/gjs-gts-processor-test.js

@@ -35,6 +35,7 @@ function initESLint(options) {
       plugins: ['ember'],
       extends: ['plugin:ember/recommended'],
       rules: {
+        'lines-between-class-members': 'error',
         'no-undef': 'error',
         'ember/no-get': 'off',
         'ember/no-array-prototype-extensions': 'error',
@@ -254,3 +255,30 @@ describe('line/col numbers should be correct', () => {
     });
   });
 });
+
+describe('lint errors on the exact line as the <template> tag', () => {
+  it('correctly outputs the lint error', async () => {
+    const eslint = initESLint();
+    const code = `
+    import Component from '@glimmer/component';
+
+    export default class MyComponent extends Component {
+      constructor() {
+        super(...arguments);
+      }
+
+      foo = 'bar';
+      <template>
+        <div>
+          some totally random, non-meaningful text 
+        </div>
+      </template>
+    }
+    `;
+    const results = await eslint.lintText(code, { filePath: 'my-component.gjs' });
+
+    const resultErrors = results.flatMap((result) => result.messages);
+    expect(resultErrors).toHaveLength(1);
+    expect(resultErrors[0].message).toBe('Expected blank line between class members.');
+  });
+});