🏗🚀 Significantly speed up gulp prettify

[rsimha]

PR Highlights:

• No longer invokes node_modules/.bin/prettier once per file
• Uses the gulp-prettier package to stream all files
• Continues to print all formatting errors after execution

Time to check / fix ~300 files:

• Before: ~1m 30s
• After: ~5s

[estherkim]

Was curious so I checked gulp-prettier. Looks like we will have version mismatches if we use this.
https://github.com/bhargavrpatel/gulp-prettier/blob/master/package.json#L31

Do we need to use this gulp plugin? Can we use prettier directly?

[rsimha]

Worthwhile question to ask, but this isn't a problem. With node's semantic versioning, the plugin will continue to use our version until the major version of prettier changes. At that point, the renovate upgrade PR for prettier will catch any resulting errors.

amphtml: 1.18.2
gulp-prettier: ^1.5.3

This means the plugin will use the latest available version that doesn't change the major version 1.

Sanity check 1: yarn.lock confirms that only version 1.18 is installed to node_modules.

Sanity check 2: The quoteProps option (that we rely on) was only added in version 1.17. If gulp-prettier were using version 1.5, it wouldn't be able to parse .prettierrc.

[estherkim]

TIL. Thanks for the detailed explanation!