a hook for jsonnet formatting

[gaurav517]

I am trying to write a hook to format jsonnet files.

Goal is: If a changed file is *.jsonnet or *.libsonnet, then run jsonnetfmt -i <file_path>. (Assuming jsonnetfmt in the path)

What would be the best approach? I believe system language would work? Is there an example that could help me?

Thanks.

[gaurav517]

ok.. I got it:

- id: jsonnet-format
  name: jsonnet/libsonnet files should be formatted
  description: formats jsonnet/libsonnet files
  entry: '/usr/local/bin/jsonnetfmt -i'
  files: \.(jsonnet|libsonnet)$
  language: system

[paulhfischer]

you might have a look at the go implementation of jsonnet, as one of the big benefits of using pre-commit is the automatic environment handling and installation of hooks which isn't possible with the system hook type. thus your configuration might look something like this:

repos:
-   repo: local
    hooks:
    -   id: jsonnetfmt
        name: jsonnetfmt
        entry: jsonnetfmt -i
        language: golang
        files: '\.(jsonnet|libsonnet)$'
        additional_dependencies: ["github.com/google/go-jsonnet/cmd/jsonnetfmt"]

(also it might be useful to create a PR and add pre-commit-hooks.yaml to go-jsonnet)

[gaurav517]

I am testing above hook:

I add following in .pre-commit-hooks.yaml of a repo: `git-hooks`:
- id: jsonnet-format
  name: Format should be valid for jsonnet/libsonnet files
  entry: jsonnetfmt -i
  language: golang
  files: '\.(jsonnet|libsonnet)$'
  additional_dependencies: [ "github.com/google/go-jsonnet/cmd/jsonnetfmt" ]

so I run pre-commit try-repo ~/Documents/git-hooks jsonnet-format --verbose in another repo and I see:

Format should be valid for jsonnet/libsonnet files...(no files to check)Skipped

However there is one file that has wrong formatting (apps/my/deployment/mydeploy.jsonnet). Any idea why it could be skipping that file?

[gaurav517]

Tried files: '.*\.(jsonnet|libsonnet)$'.. but same.. skipped the file.

[paulhfischer]

is the file tracked? pre-commit will only run on tracked files. also does the file have unstaged changes? else just running pre-commit won't run on this file and you'll have to use pre-commit run --all-files.

[gaurav517]

yes this file is tracked. Also the file has unstaged changes. I actually tested with pretty-format-json as well (changing a json file format). All of them are skipped

git status                                                                                                                                            
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
        modified:   apps/my/ci/file.json
        modified:   apps/my/deploy/file.jsonnet

pre-commit                                                                                                                                                         
[WARNING] Unstaged files detected.
[INFO] Stashing unstaged files to /Users/kgaurav2/.cache/pre-commit/patch1612539446.
[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
Check JSON...........................................(no files to check)Skipped
Pretty format JSON...................................(no files to check)Skipped
Format should be valid for jsonnet/libsonnet files...(no files to check)Skipped

Wonder what is happening.

[gaurav517]

in verbose mode:

pre-commit run --verbose 
[WARNING] Unstaged files detected.
[INFO] Stashing unstaged files to /Users/kgaurav2/.cache/pre-commit/patch1612539821.
Check JSON...........................................(no files to check)Skipped
- hook id: check-json
Pretty format JSON...................................(no files to check)Skipped
- hook id: pretty-format-json
Format should be valid for jsonnet/libsonnet files...(no files to check)Skipped
- hook id: jsonnet-format
[INFO] Restored changes from /Users/kgaurav2/.cache/pre-commit/patch1612539821.

patch looks fine.

[asottile]

by default pre-commit only runs on staged files -- you probably want pre-commit try-repo --all-files / pre-commit run --all-files

[paulhfischer]

if you have a look at the output, pre-commit stashed your files as you haven't added them via git add apps/my/ci/file.json apps/my/deploy/file.jsonnet.

$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   t.jsonnet

no changes added to commit (use "git add" and/or "git commit -a")

$ pre-commit
[WARNING] Unstaged files detected.
[INFO] Stashing unstaged files to /Users/paulfischer/.cache/pre-commit/patch1612540509.
jsonnetfmt...........................................(no files to check)Skipped
[INFO] Restored changes from /Users/paulfischer/.cache/pre-commit/patch1612540509.

$ git add t.jsonnet

$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
	modified:   t.jsonnet

$ pre-commit
jsonnetfmt...............................................................Passed

[gaurav517]

Thanks a lot. This works.

[gaurav517]

Another question, if we add this hook in pre-commit-hooks.yaml in https://github.com/google/go-jsonnet, then when a user uses this hook, will it download whole go-jsonnet repo in ~/.cache/pre-commit?

[asottile]

a shallow clone of that, yes

[gaurav517]

I added this hook in pre-commit-hooks.yaml in https://github.com/google/go-jsonnet, and then when I try to use this hook as:

repos:
  - repo: https://github.com/google/go-jsonnet
    rev: 4a3144a417b7eb9b1f7e56741a9e72f3155de3fa
    hooks:
      - id: jsonnet-format

then I see following error.

Traceback (most recent call last):
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/error_handler.py", line 65, in error_handler
    yield
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/main.py", line 378, in main
    return run(args.config, store, args)
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/commands/run.py", line 403, in run
    install_hook_envs(hooks, store)
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/repository.py", line 224, in install_hook_envs
    _hook_install(hook)
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/repository.py", line 82, in _hook_install
    lang.install_environment(
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/languages/golang.py", line 81, in install_environment
    cmd_output_b('go', 'get', './...', cwd=repo_src_dir, env=env)
  File "/usr/local/Cellar/pre-commit/2.10.0/libexec/lib/python3.9/site-packages/pre_commit/util.py", line 154, in cmd_output_b
    raise CalledProcessError(returncode, cmd, retcode, stdout_b, stderr_b)
pre_commit.util.CalledProcessError: command: ('/usr/local/bin/go', 'get', './...')
return code: 2
expected return code: 0
stdout: (none)
stderr:
    go: downloading github.com/sergi/go-diff v1.1.0
    go: downloading github.com/fatih/color v1.9.0
    go: downloading github.com/mattn/go-colorable v0.1.4
    go: downloading github.com/mattn/go-isatty v0.0.11
    go: downloading golang.org/x/sys v0.0.0-20191026070338-33540a1f6037
    # github.com/google/go-jsonnet/c-bindings
    libjsonnet.cpp:5:14: fatal error: 'libjsonnet.h' file not found

Any idea? Thanks.

[paulhfischer]

libjsonnet.h is located here (in another repo) and only symlinked in the go implementation. Thus when cloning the repo you would need the --recursive flag. pre-commit does that (see here).

[asottile]

looks like they're missing this directive for the cgo compiler:

https://github.com/google/go-jsonnet/blob/4a3144a417b7eb9b1f7e56741a9e72f3155de3fa/c-bindings/c-bindings.go#L14

[asottile]

oh actually hmm, this should still work -- I bet the second side-clone isn't happening when building the GOPATH

[asottile]

let me make a separate issue for that