[Aug. 9 2018] Format core JavaScript using recently add Prettier

Doing this results in a linting issue...

$ node ./node_modules/eslint/bin/eslint.js --quiet --config=.eslintrc.passing.json .

/Volumes/devdisk/dev/sites/drupal8alt.dev/core/modules/editor/js/editor.admin.es6.js
  294:13  error  'findPropertyValuesOnTag' was used before it was defined  no-use-before-define

✖ 1 problem (1 error, 0 warnings)

error Command failed with exit code 1.

:(

This patch includes only files which were changed by prettier (#2978964: Use Prettier for formatting core JavaScript).
No lint issues so far :)

yarn run v1.7.0
$ node ./node_modules/eslint/bin/eslint.js --quiet --config=.eslintrc.passing.json .
✨  Done in 12.35s.

I think we need to ignore prettier formatting in this file (locale_test.es6.js), because some test cases won't work (prettier reformats double quote to single quote or vise versa):

Before prettier:

Drupal.t('Single Quote t');
Drupal.t('Single Quote \'Escaped\' t');
Drupal.t('Single Quote ' + 'Concat ' + 'strings ' + 't');

Drupal.t("Double Quote t");
Drupal.t("Double Quote \"Escaped\" t");
Drupal.t("Double Quote " + "Concat " + "strings " + "t");

After prettier:

Drupal.t('Single Quote t');
Drupal.t("Single Quote 'Escaped' t");
Drupal.t('Single Quote ' + 'Concat ' + 'strings ' + 't');

Drupal.t('Double Quote t');
Drupal.t('Double Quote "Escaped" t');
Drupal.t('Double Quote ' + 'Concat ' + 'strings ' + 't');

Of course we need to have these test cases - because not everyone uses prettier for custom code :)

So, I've reverted ./core/modules/locale/tests/locale_test.es6.js and added it to .prettierignore

Mhh, doesn't this effects basically every kind of Drupal.t string in core?

I've found out,
we have 8 usages which start with Drupal.t("

1) 7 occurrences in locale_test.es6.js - now, it's ignored by prettier.
2) 1 occurrence in content_types.es6.js - no changes after reformat by prettier

so, we are safe.

Thank you @ApacheEx, that sounds sensible. In the future we can avoid changes, as we use prettier for new things.

Rerolled with the latest 8.6.x changes.

Forgot to run yarn run build:js.
Should be good now.

This is the sort of change we generally schedule in advance for during the beta phase of a minor, to minimize disruption to development and keep the minor branches from diverging in a way that adds merge conflicts. If #2978964: Use Prettier for formatting core JavaScript is completed in time to be backported prior to the beta (week of July 30th) then I would recommend scheduling this issue for ~Aug. 6.

Here we go (what was done in this patch):
1. Rerolled with this task: #2978964: Use Prettier for formatting core JavaScript
2. Included #2978964-38: Use Prettier for formatting core JavaScript to avoid failure tests.
3. Applied #2978964-36: Use Prettier for formatting core JavaScript (see 2978964-36-apply-after-prettier.txt) after run prettier.

now eslint rules are passed.

I'm planning to commit this on Thursday 9th. Let's try to make sure we have a patch that is committable tomorrow around 2 pm UTC.

Has #2978964-38: Use Prettier for formatting core JavaScript been addressed?

@xjm - yes, yes.
I've added ./core/modules/locale/tests/locale_test.es6.js to the .prettierignore

Confirmed the same steps and skimmed through the patch quickly to see that it looks correct. Committed to 8.7.x and backported to 8.6.x. Thank you for everyone involved!