playwright/tests/playwright-test/expect-poll.spec.ts

/**
 * Copyright Microsoft Corporation. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { test, expect } from './playwright-test-fixtures';

test('should poll predicate', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should poll sync predicate', async () => {
        let i = 0;
        await test.expect.poll(() => ++i).toBe(3);
      });
      test('should poll async predicate', async () => {
        let i = 0;
        await test.expect.poll(async () => {
          await new Promise(x => setTimeout(x, 50));
          return ++i;
        }).toBe(3);
      });
      test('should poll predicate that returns a promise', async () => {
        let i = 0;
        await test.expect.poll(() => Promise.resolve(++i)).toBe(3);
      });
    `
  });
  expect(result.exitCode).toBe(0);
  expect(result.passed).toBe(3);
});

test('should compile', async ({ runTSC }) => {
  const result = await runTSC({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should poll sync predicate', async ({ page }) => {
        let i = 0;
        test.expect.poll(() => ++i).toBe(3);
        test.expect.poll(() => ++i, 'message').toBe(3);
        test.expect.poll(() => ++i, { message: 'message' }).toBe(3);
        test.expect.poll(() => ++i, { timeout: 100 }).toBe(3);
        test.expect.poll(() => ++i, { message: 'message', timeout: 100 }).toBe(3);
        test.expect.poll(async () => {
          await new Promise(x => setTimeout(x, 50));
          return ++i;
        }).toBe(3);
        test.expect.poll(() => Promise.resolve(++i)).toBe(3);

        // @ts-expect-error
        await test.expect.poll(() => page.locator('foo')).toBeEnabled();
        // @ts-expect-error
        await test.expect.poll(() => page.locator('foo')).not.toBeEnabled();
      });
    `
  });
  expect(result.exitCode).toBe(0);
});

test('should respect timeout', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async () => {
        await test.expect.poll(() => false, { timeout: 100 }).toBe(3);
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('Timeout 100ms exceeded while waiting on the predicate');
  expect(result.output).toContain('Received: false');
  expect(result.output).toContain(`
  4 |         await test.expect.poll(() => false, { timeout: 100 }).
  `.trim());
});

test('should fail when passed in non-function', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async () => {
        await test.expect.poll(false).toBe(3);
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('Error: `expect.poll()` accepts only function as a first argument');
});

test('should fail when used with web-first assertion', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async ({ page }) => {
        await test.expect.poll(() => page.locator('body')).toHaveText('foo');
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('Error: `expect.poll()` does not support "toHaveText" matcher');
});

test('should time out when running infinite predicate', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async ({ page }) => {
        await test.expect.poll(() => new Promise(x => {}), { timeout: 100 }).toBe(42);
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('Timeout 100ms exceeded');
});

test('should show error that is thrown from predicate', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async ({ page }) => {
        await test.expect.poll(() => { throw new Error('foo bar baz'); }, { timeout: 100 }).toBe(42);
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('foo bar baz');
});

test('should not retry predicate that threw an error', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async ({ page }) => {
        let iteration = 0;
        await test.expect.poll(() => {
          if (iteration++ === 0)
            throw new Error('foo bar baz');
          return 42;
        }).toBe(42);
      });
    `
  });
  expect(result.exitCode).toBe(1);
  expect(result.output).toContain('foo bar baz');
});

test('should support .not predicate', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async ({ page }) => {
        let i = 0;
        await test.expect.poll(() => ++i).not.toBeLessThan(3);
        expect(i).toBe(3);
      });
    `
  });
  expect(result.exitCode).toBe(0);
});

test('should support custom matchers', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      expect.extend({
        toBeWithinRange(received, floor, ceiling) {
          const pass = received >= floor && received <= ceiling;
          if (pass) {
            return {
              message: () =>
                "expected " + received + " not to be within range " + floor + " - " + ceiling,
              pass: true,
            };
          } else {
            return {
              message: () =>
                "expected " + received + " to be within range " + floor + " - " + ceiling,
              pass: false,
            };
          }
        },
      });

      import { test, expect } from '@playwright/test';
      test('should poll', async () => {
        let i = 0;
        await test.expect.poll(() => ++i).toBeWithinRange(3, Number.MAX_VALUE);
      });
    `
  });
  expect(result.exitCode).toBe(0);
  expect(result.passed).toBe(1);
});

test('should respect interval', async ({ runInlineTest }) => {
  const result = await runInlineTest({
    'a.spec.ts': `
      import { test, expect } from '@playwright/test';
      test('should fail', async () => {
        let probes = 0;
        const startTime = Date.now();
        await test.expect.poll(() => ++probes, { timeout: 1000, intervals: [0, 10000] }).toBe(3).catch(() => {});
        // Probe at 0 and epsilon.
        expect(probes).toBe(2);
        expect(Date.now() - startTime).toBeLessThan(5000);
      });
    `
  });
  expect(result.exitCode).toBe(0);
});