Add GitHub workflow for checking code format

[hiuns]

This PR solves #17

Add an Action to enforce Go code formatting using gofmt and block unformatted code. This PR intentionally excludes lint since it requires external dependencies. It also intentionally doesn't auto-commit formatted code on push, as preferences vary.

Changes

• Workflow: lint.yaml checks formatting using gofmt. Named "lint.yaml" instead of "check-format.yaml" because it's meant to be extended in the future.

Future Improvements

1. Consider other lint options such as line length, typo, and case-consistency.
2. Consider auto-committing format/lint fixes after making a PR.

Usage

• Locally:
  • Run bazelisk run @go_sdk//:bin/gofmt -- -w .
• CI/CD:
  • Runs on pull_request.

[dayeol]

Hi @hiunshim!

Thank you for the PR!

We use Bazel instead of Make for our build system.
In Bazel, we already import rules_go, which includes the SDK with gofmt binary in it.
Thus, you can run the following command to invoke gofmt without installing anything

bazelisk run @go_sdk//:bin/gofmt -- -w .

Could you please change it to use the bazel command, instead of make?
Also, I think CI/CD needs to fail if gofmt changes any file after running it.

[hiuns]

Hi @dayeol!

Thank you for reviewing the PR and giving me detailed explanation.
I updated it to use Bazel instead of Make as requested.

I considered two options:

1. format all go files
2. format only staged files (through git diff)

I think option 1 is sufficient at the moment so I chose that. I read that Github Actions runners are ephemeral so no files will persist after the job.

I'll also link option 2 code snippet for future reference. Option 2 has been tested separately as well, but the overhead was unclear compared to option 1.

Tests
CI/CD Passing Test: https://github.com/hiunshim/manatee/actions/runs/12444917699
CI/CD Breaking Test: https://github.com/hiunshim/manatee/actions/runs/12444919510

Tests Screenshot

[dayeol]

@hiunshim Thank you! This PR LGTM.

[hiuns]

@dayeol Awesome! Could you please merge it? It says "Merging is blocked - Merge is not an allowed merge method in this repository. Only those with write access to this repository can merge pull requests."