rails_helper.rb's only logic was to require
spec_helper.rb.

Using the sed script from
https://gitlab.com/gitlab-org/gitlab-ce/issues/59758

The issue arose when the branch name contained Vue template
JavaScript. The fix is to use `v-pre` which disables Vue
compilation in a template.

https://gitlab.com/gitlab-org/gitlab-ce/issues/48034

First, transitions between can_be_merged & cannot_be_merged are removed,
as they are currently blocked in `check_if_can_be_merged`.
`can_be_merge` always returns to `unchecked` first,
before it can transition to `cannot_be_merged` (and vice versa).

We want to avoid repeated notification triggered by repeated transition
between `cannot_be_merged` & `unchecked`.

So we added `cannot_be_merged_recheck` state, similar to `unchecked`,
but as a mean to remember it’s from cannot_be_merged.

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18042/#note_65945407

Since `unchecked` and `cannot_be_merged_recheck` both mean
“we are in the middle of checking if it is mergeable”,
quite often we need to see if merge_status is in either one of them,
so `check_state?` is added to achieve this.

Signed-off-by: NRémy Coutable <remy@rymai.me>

Tip from
https://robots.thoughtbot.com/write-reliable-asynchronous-integration-tests-with-capybara#directly-interacting-with-javascript

Tip from
https://robots.thoughtbot.com/write-reliable-asynchronous-integration-tests-with-capybara#directly-interacting-with-javascript

Replaces all the explicit include metadata syntax in the specs (tag:
true) into the implicit one (:tag).
Added a cop to prevent future errors and handle autocorrection.

The dispatcher was trying to create a new instance of a class that is loaded in a file after main.js which would cause the filtered search to not work on issues. This would only happen on the first load when the JS is not cached. If the JS is cached, then everything will be fine.

Signed-off-by: NRémy Coutable <remy@rymai.me>

Otherwise some features would go untested in non-specific contexts

I did need to disable the
`gitlab_git_diff_size_limit_increase`-feature in some specs since we
depend on diffs being expandable while the file we are testing on is
smaller than the increased limit.

This is controlled with the feature flag gitlab_git_diff_size_limit_increase.
Both of these limits were basically picked arbitrarily in the first place;
disabling the feature flag reverts to the old limits.

Use the EnforcedStyleForMultiline: no_comma option.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Removed all the unnecessary include of `WaitForAjax` and `ApiHelpers` in the specs.
Removed unnecessary usage of `api:true`

- Use a store base object to manage application state.
- Add a service to handle ajax requests.
- Load code only when needed