VS Code problemMatcher-friendly reporter

[danvk]

I'd like to have a VS Code Task for knip that has a problemMatcher. The output format of knip isn't the best for parsing. Here's an example of what I see:

$ pnpm lint:knip
Analyzing workspace ....
Unused devDependencies (1)
ts-node  package.json
Unused exports (3)
runFile        function  src/main.ts:10:23
runPrompt      function  src/main.ts:15:23
tokenToString  function  src/token.ts:10:17

Here's a problemMatcher that I've written that at least matches the "Unused exports" bit:

{
	"type": "npm",
	"script": "lint:knip",
	"label": "npm: lint:knip",
	"detail": "knip",
	"problemMatcher": {
		"owner": "tsc",
		"fileLocation": ["relative", "${workspaceFolder}"],
		"pattern": [
			{
				"regexp": "^([^\\s].*) \\(\\d+\\)$",
				"message": 1
			},
			{
				"regexp": "([^ ]+) +([^ ]+) +([^:]+):(\\d+):(\\d+)",
				"file": 3,
				"line": 4,
				"column": 5,
				"loop": true
			}
		]
	}
}

This works pretty well:

But it's a bit of a bummer that I had to write these regexes and that there aren't line numbers for the unused devDependencies.

So call this a feature request for a new reporter that's compatible with one of VS Code's built-in problem matchers, for example "tsc" or "eslint".

[webpro]

The output format of knip isn't the best for parsing.

Did you see the JSON reporter? https://knip.dev/features/reporters#json

This works pretty well:

Nice! Great to see Knip used like this.

there aren't line numbers for the unused devDependencies

That's a good RFC.

So call this a feature request for a new reporter that's compatible with one of VS Code's built-in problem matchers, for example "tsc" or "eslint".

What would be the best way to go about this? Use the JSON reporter as a basis, or implement a new reporter for VS Code? Either way, I'll try to read up on the topic a bit more when I can, I'm not familiar with this part of VS Code at all.

Anybody reading this, definitely feel free to pick this up, might be a fun task.

[danvk]

The output format of knip isn't the best for parsing.

Did you see the JSON reporter? https://knip.dev/features/reporters#json

Yes! You'd think JSON output would be perfect for consuming from another tool, but so far as I can tell VS Code problemMatchers really want line-based output.

This works pretty well:

Nice! Great to see Knip used like this.

there aren't line numbers for the unused devDependencies

That's a good RFC.

Want me to file an issue for this?

So call this a feature request for a new reporter that's compatible with one of VS Code's built-in problem matchers, for example "tsc" or "eslint".

What would be the best way to go about this? Use the JSON reporter as a basis, or implement a new reporter for VS Code? Either way, I'll try to read up on the topic a bit more when I can, I'm not familiar with this part of VS Code at all.

Anybody reading this, definitely feel free to pick this up, might be a fun task.

I'd suggest implementing a new reporter that outputs in the exact same format as eslint, tsc or some other tool that VS Code has a built-in matcher for.

[beaussan]

Yes! You'd think JSON output would be perfect for consuming from another tool, but so far as I can tell VS Code problemMatchers really want line-based output.

Did you try creating a custom reporter that is vscode problemMatchers friendly ?

[danvk]

Did you try creating a custom reporter that is vscode problemMatchers friendly ?

That's what this issue is proposing :) I haven't taken a crack at it myself yet.