Use prettier to format source files

[mesaugat]

• Added prettier and tslint-config-prettier as dev dependencies
• Added a npm script to run prettier from the CLI: npm run prettier
• Formats .js, .ts, .tsx, .json and .md files
• Added .prettierrc file with a basic configuration
• Included a .prettierignore for ignoring files that don't require prettier
• tslint-config-prettier has been added to tslint.json. It helps in the removal of conflicts between tslint rules and prettier
• Another npm script has been added to check for conflicting rules npm run tslint:check. The following rules were detected as conflicts by tslint-config-prettier and have been removed from tslint.json

  max-line-length
  no-irregular-whitespace
  no-unnecessary-semicolons
  number-literal-format
  object-literal-key-quotes
  quotemark
  space-within-parens
  trailing-comma
  whitespace

• tslint:check has been added to the test script
• recommended_ruleset.js is now generated using single quotes. Also, to avoid conflicts with prettier, recommended_ruleset.js has been added to .prettierignore
• All files have been formatted using prettier
• Updated tests after running prettier
• Added husky and lint-staged to run prettier as a pre-commit hook

Fixes #558

[mesaugat]

I forgot to run the tests, it's failing. 😞

[IllusionMH]

Fitrst of all - thanks for efforts and PR, unified formatting is great.

This project used single quotes that were enforced with TSLint and as I can see - there are many files with only quotes changes.
IMHO it makes sense to add singleQuote: true to .prettierrc file.

Other things to consider:

• add prettier to the end of test script.
  There are several files that are created during npm test that will have conflicting formatting (rule-metadata.json, recommended_ruleset.js) and would be great to have them formatted accordingly.
  Do you know how long npm run prettier takes?

• Update build-tasks/templates/rule.template.js to match formatting or run prettier after it (I can help with passing arguments to scripts within npm-run-all).

• Update build tasks to output JSON with 4 spaces instead of 2 (not necessary if prettier script will be added to test and create-rule but nice to have)

[mesaugat]

I'll fix the tests too.

[JoshuaKGoldberg]

Awesome, this'll make our code a lot cleaner! A few small comments on top of IllusionMH's, then this should be good to merge!

[JoshuaKGoldberg]

Yes please, a pre-commit hook would be best. Husky is pretty great.

[JoshuaKGoldberg]

Waiting on a pre-commit hook and recommending the VS Code extension.

[IllusionMH]

Checked everything except test-data and src/test.
There are 2 comments that should be fixed.

[IllusionMH]

Also concatenation can be removed in next lines, since now that are on one line anyway (probably in follow up PR)

build-tasks/generate-sdl-report.js:13
src/chaiVagueErrorsRule.ts:10
src/chaiVagueErrorsRule.ts:12
src/insecureRandomRule.ts:7
src/insecureRandomRule.ts:9
src/jqueryDeferredMustCompleteRule.ts:26
src/missingJsdocRule.ts:28
src/noDuplicateCaseRule.ts:30
src/reactA11yRoleSupportsAriaPropsRule.ts:43
src/reactA11yRoleSupportsAriaPropsRule.ts:12

[mesaugat]

@IllusionMH I've removed the concatenations too. These were just some aesthetic changes thus pushed it here.

[IllusionMH]

I've removed the concatenations too.
Great!

I've checked on Windows in VS Code. Both pre-commit and "editor.formatOnSave": true, works great with Prettier.

@mesaugat Thanks! There are no more notes from my side 👍

[JoshuaKGoldberg]

Ahh, merge conflicts. I'll try to get to these tonight if I have permissions for the branch.

[IllusionMH]

👍 That was fast conflict resolving 😮

[mesaugat]

Didn't have to do anything, just git pull origin master -X theirs ¯\(ツ)/¯

[JoshuaKGoldberg]

Tested this out locally and it works like a charm. Thanks so much @mesaugat for sending this in and working on it, and @IllusionMH for the great reviews! 🙌

[mesaugat]

@IllusionMH @JoshuaKGoldberg Thank you guys! 🥇

Also, I forgot to mention but I had a hard time making changes to the tests when doing this. Somehow, the tests showed an old snapshot of expected/actual even though I changed some of the tests.

I've not looked into the test utils but maybe the test results were being cached or something. These tests used to fail even though I changed it to make them green.