feat(cwts): Add CWTS to the /signup page in Sync optional flow

[shane-tomlinson]

Add CWTS on the /signup page as an experiment, 20% total,
10% in each bucket.

If user deselects all of the buckets, then does not send
Sync information to the browser in the login message.

As part of this, did a little refactor to how WebChannel
events are stored for testing, instead of always storing
them, store events only if in an automated testing
environment. This made me feel more comfortable storing
the event metadata into sessionStorage too, where it can
be queried from within the functional tests.

fixes #3490

@vladikoff and @mozilla/fxa-devs - r?

[shane-tomlinson]

[shane-tomlinson]

Hmm, these two tests are failing in all of my PRs right now:

Screenshot saved at: https://screencap.co.uk/images/077a1ae07983deac32f5a17cae54dad8075484e4.png
× firefox on linux 4.15.0-1052-aws - support form with an active subscription - go to support form, submits the form (28.028s)
NoSuchElement: [POST http://localhost:4444/wd/hub/session/f96b4743-3740-45bb-9597-0e385c0bb7dd/element / {"using":"css selector","value":"#splash header h1"}] Unable to locate element: #splash header h1
For documentation on this error, please visit: https://www.seleniumhq.org/exceptions/no_such_element.html
Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:25:53'
System info: host: '9b4e2edac972', ip: '172.27.0.3', os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-1052-aws', java.version: '11.0.5'
Driver info: driver.version: unknown
at Command. @ tests/functional/lib/helpers.js:2044:6
at Command. @ tests/functional/lib/helpers.js:61:10
at Command. @ tests/functional/lib/helpers.js:75:18
at Command. @ tests/functional/lib/helpers.js:69:10
at Command. @ tests/functional/lib/helpers.js:2463:6
at Command. @ tests/functional/lib/helpers.js:61:10
at Command. @ tests/functional/lib/helpers.js:69:10
at Test.go to support form, submits the form [as test] @ tests/functional/support.js:65:10
@ src/lib/Test.ts:263:51

Screenshot saved at: https://screencap.co.uk/images/077a1ae07983deac32f5a17cae54dad8075484e4.png
× firefox on linux 4.15.0-1052-aws - support form with an active subscription - go to support form, cancel, redirects to subscription management (26.866s)
NoSuchElement: [POST http://localhost:4444/wd/hub/session/f96b4743-3740-45bb-9597-0e385c0bb7dd/element / {"using":"css selector","value":"#splash header h1"}] Unable to locate element: #splash header h1
For documentation on this error, please visit: https://www.seleniumhq.org/exceptions/no_such_element.html
Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:25:53'
System info: host: '9b4e2edac972', ip: '172.27.0.3', os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-1052-aws', java.version: '11.0.5'
Driver info: driver.version: unknown
at Command. @ tests/functional/lib/helpers.js:2044:6
at Command. @ tests/functional/lib/helpers.js:61:10
at Command. @ tests/functional/lib/helpers.js:75:18
at Command. @ tests/functional/lib/helpers.js:69:10
at Command. @ tests/functional/lib/helpers.js:2463:6
at Command. @ tests/functional/lib/helpers.js:61:10
at Command. @ tests/functional/lib/helpers.js:69:10
at Test.go to support form, cancel, redirects to subscription management [as test] @ tests/functional/support.js:94:10
@ src/lib/Test.ts:263:51

[vbudhram]

@shane-tomlinson This LGTM 👍🏽, should we target 151?

[vladikoff]

works well in my testing.

At what point are we gonna clean up the logic for this and remove the experiment (so this is the only code path)?

[shane-tomlinson]

At what point are we gonna clean up the logic for this and remove the experiment (so this is the only code path)?

I'd like to as soon as we are confident we aren't going to roll back. Seems like it should be somewhat straight forward.

[shane-tomlinson]

@sv-sdeiac - this can be tested on https://stomlinson.dev.lcip.org

To test:

1. Use either Fx 71 or Fx 72.
2. Create a new profile
3. Open about:config:

• edit identity.fxaccounts.autoconfig.uri to https://stomlinson.dev.lcip.org
• edit browser.newtabpage.activity-stream.fxaccounts.endpoint to https://stomlinson.dev.lcip.org/ (note the trailing slash)

4. Restart the browser.
5. Click the "FxA toolbar icon" and click "Sign in to Firefox" (this initializes the rest of the about:config values)
6. open about:welcome
7. Sign up for a new account, on /signup, deselect all of the buckets
8. After verifying, in the FxA toolbar icon, ensure it says "Setup Sync" instead of "Sync now"
9. Sign out
10. Open "https://stomlinson.dev.lcip.org/clear"
11. Click the FxA toolbar icon again and click "Sign in to Firefox" (this re-initializes the about:config values, they were reset on signout).
12. Open about:welcome
13. Sign up for another new account, this time, deselect a few buckets but not all.
14. Verify the account, ensure "Sync now" shows in the FxA toolbar.
15. Open sync preferences and ensure only the expected buckets are enabled.

[vasilicatamas]

I'm removing the needs:qa label considering that this implementation has been verified by the QA team and the signoff mail, with the testing results, was sent yesterday.