[Bug]: Fixture array parameter error

[mkrakker]

Version

1.46.1

Steps to reproduce

poc.ts:

import { expect, test as base } from '@playwright/test';

type FixtureOptions = {
  data: { foo: string, bar: string }[];
};

const testFixture = base.extend<FixtureOptions>({
  data: [[], { option: false }],
  page: async ({ page, data }, use) => {
    if (!data || !data.length) {
      // data is just { "foo": "foo", "bar": "bar" } instead of an array at this point
      throw new Error(':(');
    }

    await use(page);
  }
});

testFixture.describe('POC', () => {
  testFixture.use({
    data: [
      { foo: 'foo', bar: 'bar'},
      { foo: 'bar', bar: 'foo'}
    ]
  });

  testFixture('Should pass', async ({ page }) => {
    expect(true).toBeTruthy();
  });
});

playwright.config.ts:

import { defineConfig, devices } from '@playwright/test';
export default defineConfig({
  testDir: './tests',
  fullyParallel: false,
  forbidOnly: !!process.env.CI,
  retries: 0,
  workers: 1,
  reporter: 'html',
  use: {
    trace: 'on',
  },

  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    }
  ],
});

Expected behavior

The test passes, as the passed data fixture parameter is an array

Actual behavior

The test fails in the fixture o nthe parameter validation, as data has no length property - in fact it is the first element of the array passed in in use

Additional context

Works fine with 1.45.3

Environment

System:
    OS: Windows 11 10.0.22631
    CPU: (12) x64 13th Gen Intel(R) Core(TM) i5-1335U
    Memory: 17.32 GB / 31.69 GB
  Binaries:
    Node: 20.12.2 - C:\Program Files\nodejs\node.EXE
    npm: 10.2.4 - C:\Program Files\nodejs\npm.CMD
    pnpm: 8.14.0 - ~\AppData\Roaming\npm\pnpm.CMD
  IDEs:
    VSCode: 1.92.2 - C:\Program Files\Microsoft VS Code\bin\code.CMD
  Languages:
    Bash: 5.1.16 - C:\Windows\system32\bash.EXE
  npmPackages:
    @playwright/test: 1.46.1 => 1.46.1
    playwright: 1.46.1 => 1.46.1

[Skn0tt]

Hi there! Passing an array is a common footgun that others have seen before - #32033 is a similar report. We added a note about this to the docs just yesterday, so they're not yet live. But you can take a look here: https://github.com/microsoft/playwright/pull/32261/files#diff-39680f5caa0a24f2a0eaa7c7313f170b4e2d2e15d451d4d47f026bfea933b57fR554

Let me know if that solves it for you!

[mkrakker]

Hi @Skn0tt ! Indeed wrapping the input array in another array is a feasible workaround, I can confirm this. (also wrapping the array in an object seems to work just fine)
Thanks a lot :)

[MindaugasMateika]

Hi there! Passing an array is a common footgun that others have seen before - #32033 is a similar report. We added a note about this to the docs just yesterday, so they're not yet live. But you can take a look here: https://github.com/microsoft/playwright/pull/32261/files#diff-39680f5caa0a24f2a0eaa7c7313f170b4e2d2e15d451d4d47f026bfea933b57fR554

Let me know if that solves it for you!

Hi there! Passing an array is a common footgun that others have seen before - #32033 is a similar report. We added a note about this to the docs just yesterday, so they're not yet live. But you can take a look here: https://github.com/microsoft/playwright/pull/32261/files#diff-39680f5caa0a24f2a0eaa7c7313f170b4e2d2e15d451d4d47f026bfea933b57fR554

Let me know if that solves it for you!

Why it was not listed as a breaking change anywhere in the release notes? I'm upgrading from 1.45 to 1.48.2 and spent like half a day figuring out why TypeError: someOptionArray is not iterable error and why array option is suddenly an object.