Test flow types are stripped before class properties are transformed

fixtures/smoke/issue-5176-flow-class-properties/index.test.js

+const { bootstrap, isSuccessfulTest } = require('../../utils');
+beforeEach(async () => {
+  await bootstrap({ directory: global.testDirectory, template: __dirname });
+});
+
+describe('issue #5176 (flow class properties interaction)', () => {
+  it('passes tests', async () => {
+    await isSuccessfulTest({
+      directory: global.testDirectory,
+      jestEnvironment: 'node',
+    });
+  });
+});

fixtures/smoke/issue-5176-flow-class-properties/package.json

+{}

fixtures/smoke/issue-5176-flow-class-properties/src/App.js

+class App {
+  constructor(props) {
+    super(props);
+    this.foo = this.foo.bind(this);
+  }
+  foo: void => void;
+  foo() {
+    return 'bar';
+  }
+}
+
+export default App;

fixtures/smoke/issue-5176-flow-class-properties/src/App.test.js

+import App from './App';
+
+it('creates instance without', () => {
+  const app = new App();
+  expect(app.foo()).toBe('bar');
+});

fixtures/utils.js

@@ -67,6 +67,21 @@ async function isSuccessfulProduction({ directory }) {
   }
 }
 
+async function isSuccessfulTest({ directory, jestEnvironment = 'jsdom' }) {
+  const { status, stdout, stderr } = await execa(
+    './node_modules/.bin/react-scripts',
+    ['test', '--env', jestEnvironment, '--ci'],
+    {
+      cwd: directory,
+      env: { CI: 'true' },
+    }
+  );
+
+  if (status !== 0) {
+    throw new Error(`stdout: ${stdout}${os.EOL + os.EOL}stderr: ${stderr}`);
+  }
+}
+
 async function getOutputDevelopment({ directory, env = {} }) {
   try {
     const { stdout, stderr } = await execa(
@@ -128,6 +143,7 @@ module.exports = {
   bootstrap,
   isSuccessfulDevelopment,
   isSuccessfulProduction,
+  isSuccessfulTest,
   getOutputDevelopment,
   getOutputProduction,
 };