fix isTestFile (#2147)

Author: NullVoxPopuli

lib/utils/ember.js

@@ -175,8 +175,10 @@ function isModuleByFilePath(filePath, module) {
   );
 }
 
+const validFileExtensions = ['js', 'ts', 'gjs', 'gts'];
+
 function isTestFile(fileName) {
-  return fileName.endsWith('-test.js') || fileName.endsWith('-test.ts');
+  return validFileExtensions.some((ext) => fileName.endsWith(`-test.${ext}`));
 }
 
 function isMirageDirectory(fileName) {

tests/lib/utils/ember-test.js

@@ -139,6 +139,8 @@ describe('isTestFile', () => {
   it('detects test files', () => {
     expect(emberUtils.isTestFile('some-test.js')).toBeTruthy();
     expect(emberUtils.isTestFile('some-test.ts')).toBeTruthy();
+    expect(emberUtils.isTestFile('some-test.gjs')).toBeTruthy();
+    expect(emberUtils.isTestFile('some-test.gts')).toBeTruthy();
   });
 
   it('does not detect other files', () => {