Cannot invoke plugins from command line

[lucteo]

Hi

I'm trying to add swift-format to our project; we aim at being able to run this manually, and from our CI pipeline.
swift-format is added as a dependency in our Package.swift. (in my tests, I'm using 0.50800.0-SNAPSHOT-2022-12-29-a tag).

If I run "Lint Source Code" or "Format Source Code" from XCode, everything works ok.
However, If I try to run it from command line, I get the following errors:

$ swift package plugin lint-source-code
Building for debugging...
Build complete! (0.58s)
Error: '--recursive' is only valid when formatting or linting files
Usage: swift-format lint [--configuration <configuration>] [--assume-filename <assume-filename>] [--recursive] [--ignore-unparsable-files] [--parallel] [--color-diagnostics] [--no-color-diagnostics] [<paths> ...] [--strict]
  See 'swift-format lint --help' for more information.
error: swift-format invocation failed: NSTaskTerminationReason(rawValue: 1):64

Can you please help me make this work?

Thank you very much

[dabrahams]

Lucian do you have a pointer to the package plugin you're working with?

[lucteo]

The ones included in swift-format: https://github.com/apple/swift-format/tree/main/Plugins (in the above example, I'm using the linter plugin)

[dabrahams]

I see, there are no tests for those in the project. Nice. You can use "swift package edit swift-format" and then go in and add printing to the place where the command is issued, to see what it's actually trying to do.

[dabrahams]

My guess is that this thing should not be trying to use --recursive at all. Its logic is very weird, such that it lints everything that lives in the same directory as any target file, whether it's a target or not. Also submits a directory for each target file, without uniquing them, which could be problematic depending on how SPM deals with it.

[macshome]

When invoking the lint command in Xcode the plugin is being passed the project directory, hence the --recursive argument.

The lint plugin is hardcoded with "--recursive", "--parallel", "--strict" as arguments which isn't really what I expected.

The default of using --strict for the lint plugin causes it to exit with a 1 and always throw an error.

[macshome]

I'm going to open a PR for the strict thing, but I also debugged the issues that @lucteo was running into.

The command plugins operate on a target, currently, not a directory. So you need to tell it what target to lint.

For example: swift package plugin lint-source-code --target swift-format

This mirrors the behavior of the Xcode plugin, if you want to run swift-format as a tool on a directory I would just call it directly.

[dabrahams]

Maybe I'm misunderstanding the logic I described here, but by my reading it looks like it would seem to work in “normal” projects, but break in unusual projects, e.g. when there are non-target swift files in the same directory as Swift files. I also think you should reconsider whether it's really right to submit whole directories to swift-format.

[lucteo]

I can confirm that adding --target to the command line makes the tool succeed. Thank you very much

Does this tool make sense to be run at the directory level?

(in any case, I would argue that we need to fix the tool to properly indicate the user the need of specifying a target)

[macshome]

In the context of using a plugin though the target that is passed is the directory that the target code lives in. It doesn't seem to have any other way of passing a location. It also though only seems to read .swift files and there is an option to ignore non-parseable files.

When running as a standalone tool, swift-format seems to have more flexibility on the input.

[dabrahams]

That's very strange. The plug-in I built gets passed individual files: https://github.com/dabrahams/citron/blob/ecfdaf5db81dcea8c7162f85e6defc5a7052b618/Plugins/CitronParserGenerator/CitronParserGenerator.swift

[macshome]

Ahh, that helps immensely and I can get the source files now from the target.

When using --recursive though it's already building a file list of the .swift files in the project directory with the FileItereator utility.

Honestly I don't have a lot of use for the lint command plugin as the warnings don't show up in Xcode as they aren't build warnings. For that we need a BuildPlugin.

I'll make a new issue for the removal of --strict in the lint plugin default args and open a PR for it. The code isn't very testable for that sort of thing, but I'll try to figure something out.

For the scope of this particular ticket it seems that calling a Command Plugin without a target specified was the actual issue. I think that can probably be fixed with documentation on how to call a command plugin from the CLI.

[macshome]

Opened PR #489 for the --strict thing.

[soumyamahunt]

(in any case, I would argue that we need to fix the tool to properly indicate the user the need of specifying a target)

@lucteo @macshome I would suggest the plugin should pick all the targets in the absence of specific targets. Instead of this:

swift-format/Plugins/FormatPlugin/plugin.swift

Line 41 in 5bcfbff

let targetsToFormat = try context.package.targets(named: targetNames)

we should have this:

let targetsToFormat = targetNames.isEmpty ? context.package.targets : try context.package.targets(named: targetNames)