Test transform from media to embed blocks

[draganescu]

Closes #11901

Added e2e tests to test the transform of audio, video and image blocks in to embeds when embeddable URLs are provided

Description

Added e2e tests to test the transform of audio, video and image blocks in to embeds when embeddable URLs are provided

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.

[draganescu]

I added the mocking of audio and image test URLs and also used the video URL which was already mocked.

[draganescu]

The undo tests seem to fail for everyone on travis, for some they work on local.

Ran locally they fail because of a timeout. Interestingly, setting the timeout to be higher using both jest.setTimeout( 100000 ); and PUPPETEER_TIMEOUT=10000 has no effect.

Running in playback mode results in the same timeout, although visual inspection shows undo does work!

[aduth]

Yes, the Undo tests are very unstable at the moment. I'm hoping this is improved with #14108.

[draganescu]

rebased and changed @noisysocks requested changes

[noisysocks]

Looks like Travis might be reporting a legitimate test failure:

FAIL specs/embedding.test.js (62.532s)
  ● Embedding content › should transform from audio to embed block when Soundcloud URL is pasted
    waiting for selector ".wp-block-embed-soundcloud" failed: timeout 30000ms exceeded
      271 | 		await page.keyboard.type( 'https://soundcloud.com/a-boogie-wit-da-hoodie/swervin' );
      272 | 		await page.keyboard.press( 'Enter' );
    > 273 | 		await page.waitForSelector( '.wp-block-embed-soundcloud' );
          | 		           ^
      274 | 	} );
      275 | } );
      276 | 
      at new WaitTask (../../node_modules/puppeteer/lib/FrameManager.js:840:28)
      at Frame._waitForSelectorOrXPath (../../node_modules/puppeteer/lib/FrameManager.js:731:12)
      at Frame.waitForSelector (../../node_modules/puppeteer/lib/FrameManager.js:690:17)
      at Page.waitForSelector (../../node_modules/puppeteer/lib/Page.js:1008:29)
      at Object.waitForSelector (specs/embedding.test.js:273:14)
      at tryCatch (../../node_modules/regenerator-runtime/runtime.js:62:40)
      at Generator.invoke [as _invoke] (../../node_modules/regenerator-runtime/runtime.js:288:22)
      at Generator.prototype.(anonymous function) [as next] (../../node_modules/regenerator-runtime/runtime.js:114:21)
      at asyncGeneratorStep (specs/embedding.test.js:9:103)
      at _next (specs/embedding.test.js:11:194)

[draganescu]

@noisysocks @youknowriad this now passes all checks.

[gziolo]

Looks good, I trust Travis it works :)