Add .pre-commit-hooks.yaml file to support https://pre-commit.com/

[aneeshusa]

We're starting to adopt golangci-lint at my workplace and it's been really great to use so far, thanks for making this useful tool. We're currently standardizing on pre-commit (https://pre-commit.com/) as our main entrypoint to run linters, since we need to support other languages like Python and having a single tool provides a unified experience for all developers. It also has a config file that lets us define the version of each linter to run in a structured format amenable to automated updates, unlike our current approach of ad-hoc lines in Dockerfiles or shell scripts, and ensures developers automatically have the correct version locally as well.

In order to run golangci-lint from pre-commit, there needs to be a .pre-commit-hooks.yaml file in the golangci-lint repo. Would it be possible to add one to this repo? I did some testing with a local checkout and it appears that the relevant settings from https://pre-commit.com/#pre-commit-configyaml---hooks would be id, name, description, entry, language, types, and pass_filenames (that one should be false I think).

I would have made a PR myself, but am still going through the legal review process at my workspace to have golangci-lint approved as an upstream (per #267), so I thought I would ask if one of the maintainers could add this file in the meantime. I am happy to review any PRs to do so.

Please include the following information:

1. Version of golangci-lint: golangci-lint --version (or git commit if you don't use binary distribution)
   golangci-lint has version 1.11.2 built from f5f7701 on 2018-10-29T14:14:06Z

[jirfag]

hi!
it looks nice to implement, I'm not sure that we can implement it soon, pull requests are welcome

[nexeck]

Couldn't you just use:

repos:
  - repo: git://github.com/dnephin/pre-commit-golang
    rev: HEAD
    hooks:
      - id: golangci-lint

[aneeshusa]

@nexeck the issue with using the hook from https://github.com/dnephin/pre-commit-golang is that it expects golangci-lint to already be installed. One of the main reasons my company are standardizing on pre-commit is that it manages installation and versioning for us, with the version of each linter to use specified in the .pre-commit-config.yaml. This means each of our repositories can have its own version to make it easier to upgrade golangci-lint versions one repo at a time without requiring developers to juggle multiple golangci-lint versions manually on their machines.

The way that the pre-commit support works for linters written in Go (like golangci-lint) is that it will install them from the repo where the hook is hosted at the specified version, hence the desire to have a .pre-commit-hooks.yaml in this repository. You could technically use additional_dependencies but that delegates to go get so I'm not aware of a way to specify a version for that.

[nexeck]

Cool, I didn't know that there is a way to not install the binary manually.

So, you already know what should be in the pr, and just the cla is a "problem" at the moment?

If you could give me any hint, I am happy to create the pr.

[nexeck]

I am getting the following error

Command

pre-commit try-repo ~/dev/nexeck/golangci-lint golangci-lint -a

.pre-commit-hooks.yaml

-   id: golangci-lint
    name: Golang CI Lint
    description: Run multiple golang linters
    entry: golangci-lint
    language: golang
    types: [go]

Error

An unexpected error has occurred: CalledProcessError: Command: ('/usr/local/bin/go', 'get', './...')
Return code: 2
Expected return code: 0
Output: (none)
Errors:
    go get: warning: modules disabled by GO111MODULE=auto in GOPATH/src;
        ignoring go.mod;
        see 'go help modules'

[aneeshusa]

@nexeck yeah, that's right, I've been testing with a .pre-commit-hooks.yaml like

- id: golangci-lint
  name: TODO
  description: TODO
  entry: golangci-lint run
  types: [go]
  language: golang
  pass_filenames: false

(Note that this isn't the canonical formatting for pre-commit YAML files, your example did that better.)

Unfortunately, out of the box I'm not aware of a way to test language: golang hooks from a local checkout in pre-commit. I've been able to check out a local copy of pre-commit and apply a small hack: https://github.com/pre-commit/pre-commit/blob/6b6ebe7e3015ac72bc3c3e4e1515975e1c009a22/pre_commit/languages/golang.py#L36-L49 will always return 'unknown_src_dir' if you use a local repo, so in testing I've had to edit that function to return 'github.com/golangci/golangci-lint', after which it works.
That won't be an issue once the .pre-commit-hooks.yaml is added to this repo, as then we can use https://github.com/golangci/golangci-lint which that function handles correctly.

[nexeck]

This seems more to be a problem with golangci-lint using go mod.
Because pre-commit clones the repo into $GOPATH, go mod is not working.

[aneeshusa]

@nexeck while it's true that pre-commit hasn't learned to handle repos using go modules (by setting $GO111MODULE or not cloning them into $GOPATH), because golangci-lint vendors its dependencies it will work using the current pre-commit implementation once the .pre-commit-hooks.yaml is added to this repo.

I agree that pre-commit should get updated, but I'd love to get the .pre-commit-hooks.yaml added here in the meantime since it will work without that fix, if you can make a PR.

[jirfag]

closing because #311 was merged