feat(adapter): update createConfig helper to use deep merge

[tanner-reits]

What is the current behavior?

With the current API, the process of overriding nested object values in the config is tedious. A user either has to use custom override options we create on a type (like webServerCommand), or use a .then() on the helper to update specific values on the generated config.

GitHub Issue Number: N/A

What is the new behavior?

The helper will now use a "deep merge" approach for overrides so only the specified properties in an object get changed, not the whole object. So, a call to the helper like:

import { expect } from '@playwright/test';
import { matchers, createConfig } from '@stencil/playwright';

expect.extend(matchers);

export default createConfig({
  // Change which test files Playwright will execute
  testMatch: '*.spec.ts',

  webServer: {
    // Only wait max 30 seconds for server to start
    timeout: 30000,
  },
});

Will generate the following config:

{
  testMatch: '*.spec.ts',
  use: {
    baseURL: 'http://localhost:3333',
  },
  webServer: {
    command: 'stencil build --dev --watch --serve --no-open',
    url: 'http://localhost:3333/ping',
    reuseExistingServer: !process.env.CI,
    // Only timeout gets overridden, not the entire object
    timeout: 30000,
  },
}

Documentation

stenciljs/site#1399

Does this introduce a breaking change?

• Yes
• No

Technically a breaking change, but this is a pre-1.0 experimental package.

Testing

Updated automated tests and confirmed the functionality in a Stencil starter project

Other information

[alicewriteswrongs]

I think this is a good and ergonomic change that makes our stuff 'closer' to playwright! I support it. I noticed one thing I think we'll want to adjust with the typing though

[alicewriteswrongs]

lgtm!

[christian-bromann]

One optional suggestion. Given the small impact of this dependency I don't think it will be a problem but still worth to consider.