Network mocking for all UI and screenshot tests

[jtreanor]

This PR updates all of our UI and screenshot tests to use mocked networking using WireMock. The mocking functionality is shared with WPAndroid from the WordPressMocks repo.

It relies on the following open PRs:

• Mocking changes for WordPress iOS UI and screenshot tests WordPressMocks#3

Other related PRs:

• Allow WordPress.com API URLs to be overridden with a launch argument #11655
• Fix some WordPress.com API injection issues #11717
• Use Environment.current.wordPressComApiBase when initializing WPStatsService #11762
• Fix WordPressScreenshotGeneration build errors #11807
• Add network mocking for end to end tests WordPress-Android#9422
• Make WordPress.com base urls configurable WordPressKit-iOS#141
• Make WordPress.com URLs configurable through WordPressAuthenticatorConfiguration WordPressAuthenticator-iOS#93
• Add scripts and files to allow running WireMock standalone WordPressMocks#1

To test:

• Check out this branch. Run rake dependencies as usual.
• Run rake mocks to start the mock server.
• Run the UI tests in the WordPressUITests target with Xcode.
• All tests should pass and there should be no errors/warnings in the terminal when you ran the mock server.

Note: The screenshot tests are broken in develop due to the recent stats changes. I think we should fix that in a separate change.

Update release notes:

• If there are user facing changes, I have added an item to RELEASE-NOTES.txt.

[rachelmcr]

I confirmed the tests in the WordPressUITests target all pass. Thanks for finishing the magic link test with the mocking!

However, I did get this warning in the terminal when I started the mock server:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

And while running the UI tests on an iPad simulator (iPad Pro, 12.9-inch, 3rd Generation), I saw a number of "Request was not matched" errors (although the tests still pass). These didn't show up when running the tests on an iPhone simulator. Here were the requests without a matching stub:

/rest/v1.2/read/sites/53424024?locale=en
/rest/v1.1/sites/158396482/stats//?locale=en&max=10
/v1.1/users/suggest?locale=en&site_id=158396482

Let me know if you need more details or can't reproduce that on your end.

Note: The screenshot tests are broken in develop due to the recent stats changes. I think we should fix that in a separate change.

Agreed, I think that's fine to address separately.

[jtreanor]

Thanks @rachelmcr!

However, I did get this warning in the terminal when I started the mock server:

This is expected and fine. It doesn't affect us.

And while running the UI tests on an iPad simulator (iPad Pro, 12.9-inch, 3rd Generation), I saw a number of "Request was not matched" errors (although the tests still pass).

Oh great, thank you! These should all be quick to fix.

[jtreanor]

Okay, I've updated wordpress-mobile/WordPressMocks#3 with the missing requests.

@rachelmcr It should all be working now. Once you pull, you will need to run rake dependencies and then rake mocks again.

[rachelmcr]

Looks great now!

[jtreanor]

Thanks, @rachelmcr! Could you also take a quick look at wordpress-mobile/WordPressMocks#3? That's where the mocks live and you have already effectively tested them by reviewing this 😄

Once that is merged, we can merge this PR and get these tests running on CI.

[jtreanor]

Okay, I have updated to the release version of WordPressMocks. There are no changes, so I will merge when green.