adding runPipeline tests

[ppisljar]

Summary

resolves #22139

• as mentioned in the ticket, we would prefer to test against real es (as that would be hard to mock)
• for testing quite some functions we actually need kibana running (as we need access to few kibana services which we would also prefer not to mock)

this implements runPipeline tests as selenium test:

• with selenium tests we have es and kibana running
• we create a simple plugin, which exposes the runPipeline wrapper on the window object
• we use executeAsync inside selenium tests to run that function with parameters we provide

the result is a simple framework that allows us to test pipeline expressions with real es and kibana running.

• its quite fast, once the page is loaded expressions can be executed in a breeze.
• debugging is simple. if a test failed, copy the expression and run it in canvas.

in long term we probably want this to be more lightweight -- hopefully jest tests, but until we get there this could serve us well, and moving to jest once we have the infrastructure ready should not be a problem as we could implement a very similar wrapper there.

Running tests

node scripts/functional_tests_server --config test/interpreter_functional/config.js
node scripts/functional_test_runner --config test/interpreter_functional/config.js

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

• [ ] This was checked for cross-browser compatibility, including a check against IE11
• [ ] Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• [ ] Unit or functional tests were updated or added to match the most common scenarios
• ~`[ ] This was checked for keyboard-only and screenreader accessibility~~

For maintainers

• [ ] This was checked for breaking API changes and was labeled appropriately
• [ ] This includes a feature addition or change that requires a release note and was labeled appropriately

[elasticmachine]

Pinging @elastic/kibana-app

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[ppisljar]

we are gonna try with a different approach

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[lukeelmers]

Nice, this is looking good to me!

2 build failures: the first will be fixed with a rebase on master, and the second is screenshot flakiness.

Sounds like we just have to discuss what to do about those screenshots... #33187 is a related issue I ran into recently that would likely be solved by this too

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[stacey-gammon]

Keep in mind we'll be getting screenshot tests with Applitools ( cc @liza-mae ). That might be a better route to verify the rendering and keep these tests just for testing the data output?

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[ppisljar]

I talked with spencer, he is ok with the partial screenshot approach, but suggested to use png resizing lib instead of canvas which requires native modules. I was suggested to use https://github.com/lovell/sharp and am giving it a try now.

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[ppisljar]

I tested new png cropping on windows and linux

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[lukeelmers]

LGTM! Tested and the new screenshots work great on OSX. Only caveat is that I don't know if the new library is really going to be helpful for maps, since it doesn't capture any of the tiles. But it certainly solves the problem for everything else.

I did notice a new console error from kbn_chrome.js, but after looking into it, I think it's likely due 4f0a57a, and the tests are still working either way.

TypeError: Cannot read property 'slice' of null
    at eval (kbn_chrome.js:80)
    at Scope.$broadcast (angular.js:18869)
    at eval (angular.js:14600)
    at Scope.$digest (angular.js:18352)
    at Scope.$apply (angular.js:18649)
    at bootstrapApply (angular.js:1958)
    at Object.invoke (angular.js:5106)
    at doBootstrap (angular.js:1956)
    at Object.bootstrap (angular.js:1976)
    at Object.chrome.bootstrap (chrome.js:96)

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request