Support Rome as a formatter

[blutorange]

Add Rome as a formatter for JavaScript and TypeScript code, #1651

A few notes regarding the design:

• How Rome is located: The NPM and Python/Black formatters currently require that either the binary is available in the path, or that one specifies the binary explicitly in the Gradle / Maven plugin. This is not ideal when the project needs to be compiled in many different environment, such as CI and pipelines, or when there are new developers who want to check out and build a project. We've been working a lot with the frontend-maven-plugin, which does not require any configuration whatsoever. It downloads the NPM binary automatically and uses that locally. So for the Rome integration, I added a similar feature: You can still specifiy the path manually if you want, but by default, the Rome binary is downloaded automatically if it does not exist yet.
  • The Rome download directory, when not given explicitly, defaults to ~/.m2/repository/com/diffplug/spotless/spotless-data ). This is also done by e.g. the dependency check Maven plugin or by the frontend-maven-plugin.
• How Rome is executed: Currently, I just execute the Rome binary for each request. Rome also offers a language server, which we could start only once and then send commands to. I don't think that's worth it, however. It offers little benefit, since Rome is already pretty fast and does not have any of the startup overhead that e.g. node.JS does have.
  • On my machine (which is not the fastest out there), formatting a short file only takes a couple of milliseconds, formatting the unminified JQuery source code file (about 10000 LOC) takes about 100ms.

TODOs

• Allow users to use the Rome executable on the path
• Automatically find the Rome config file and/or add an option to specify the config file
  • This is probably impossible due spotless' caching mechanism? As we can't format depending on the file path, and the config file would have to be derived from the file path.
• Pass on the config file to the Rome process
• Support Rome as a formatter for JSON: https://docs.rome.tools/internals/language_support/
• Support Gradle
  • As a generic format step
  • As a format step for JS/TS/JSON
• Write docs / README.md
  • Maven
  • Gradle
• Write tests
  • General
  • Maven
  • Gradle
• Test on Windows and MacOS (anybody?)

[nedtwigg]

Thanks very much, this looks great! Main feedback is just to shrink the public API as much as possible. Spotless has a ton of formatters, keeping the common API as small as possible and making each formatter as self-contained as possible is important.

[nedtwigg]

Also, add an entry here

spotless/README.md

Line 102 in d75aa9a

lib('scala.ScalaFmtStep') +'{{yes}} | {{yes}} | {{yes}} | {{no}} |',

And then run spotlessApply to update the table in the root README.

[blutorange]

So this is mostly done now, see here for docs (Maven, Gradle). If anybody has any ideas / suggestions for the configuration, feel free to mention it.

[blutorange]

Also, it would be great if somebody could test this on Windows, especially the part where it locates and downloads the Rome binary automatically for the current OS / architecture. Mac OS would also be nice.

[blutorange]

I fixed the spotbugs issues, some NPM tests are failing when I run ./gradlew build -x spotlessCheck locally, but since these are unrelated to these changes, it's probably some issue with my local environment so I hope they'll pass when run via github workflows.

[blutorange]

Can the workflow be approved again? With the latest commit it passes on a Windows machine where I tried it

[blutorange]

Hmm, those failures in the build pipeline look like a general build issue, the same error also happens on the main branch https://github.com/diffplug/spotless/actions/runs/4934286482/jobs/8819133075

[blutorange]

The hash algorithm was set to SHA256, which is supported by some system, but not all. I changed it to SHA-256 which should be supported everywhere.

[nedtwigg]

Thanks for a great PR and sorry for the slow turnaround. We'll get this merged and released this week.

[blutorange]

No problem, good things take a while ; ) Also, the build on various different OS's are very helpful to catch issues with path handling etc. There still seems to be an issue creating a path in Windows again for the gradle plugin, where Paths.get needs to be replaced with Path.of so that it handles file URIs correctly.

Edit: seems you already fixed it by removing the slash. Another option is to use Path.of instead of Paths.get

[nedtwigg]

Thanks for the Path.of hint, that's useful!

[nedtwigg]

Released in plugin-gradle 6.19.0 and plugin-maven 2.37.0.