fix(parser): adds TTY check before logging the version mismatch warning (#1121)

Author: FabioAntunes

Diff for: packages/typescript-estree/src/parser.ts

@@ -224,7 +224,11 @@ function applyParserOptionsToExtra(options: TSESTreeOptions): void {
 }
 
 function warnAboutTSVersion(): void {
-  if (!isRunningSupportedTypeScriptVersion && !warnedAboutTSVersion) {
+  if (
+    !isRunningSupportedTypeScriptVersion &&
+    !warnedAboutTSVersion &&
+    process.stdout.isTTY
+  ) {
     const border = '=============';
     const versionWarning = [
       border,

Diff for: packages/typescript-estree/tests/lib/warn-on-unsupported-ts.ts

@@ -3,20 +3,34 @@ import * as parser from '../../src/parser';
 
 jest.mock('semver');
 
+const resetIsTTY = process.stdout.isTTY;
+
 describe('Warn on unsupported TypeScript version', () => {
   afterEach(() => {
     jest.resetModules();
     jest.resetAllMocks();
+    process.stdout.isTTY = resetIsTTY;
   });
 
   it('should warn the user if they are using an unsupported TypeScript version', () => {
     (semver.satisfies as jest.Mock).mockReturnValue(false);
     jest.spyOn(console, 'log').mockImplementation();
+    process.stdout.isTTY = true;
+
     parser.parse('');
     expect(console.log).toHaveBeenCalledWith(
       expect.stringContaining(
         'WARNING: You are currently running a version of TypeScript which is not officially supported by @typescript-eslint/typescript-estree',
       ),
     );
   });
+
+  it('should not warn the user when the user is running on a non TTY process', () => {
+    (semver.satisfies as jest.Mock).mockReturnValue(false);
+    jest.spyOn(console, 'log').mockImplementation();
+    process.stdout.isTTY = false;
+
+    parser.parse('');
+    expect(console.log).not.toHaveBeenCalled();
+  });
 });