uhyo / akitainu

Unified linting tool for node.js projects

Problem

You want to add a new lint rule to existing codebase, but you cannot afford to fix all existing code.

Solution

You only check changed files with the new lint rule when a pull request is opened. This way, new files are forced to obey the new rule. Also, existing files are gradually fixed as they are modified.

akitainu helps you automate this workflow.

akitainu is inspired by reviewdog, but is for the npm ecosystem.

Usage

See also: Akitainu Website

Basically, you define rules which are composed of following configurations:

• source defines which files to check.
• checker defines what check is done against files.
• filter defines which errors to report.

The above solution is realized by sourcing from git diff. When you check existing code, you can filter out errors from the new lint rule so that the existing code is still green.

Simple Setting

The following setting runs eslint against all files matching ./src/**/*.ts. Resulting errors are not filtered.

{
  "rules": [
    {
      "source": [
        "akitainu:static-source",
        {
          "files": ["./src/**/*.ts"]
        }
      ],
      "checker": "akitainu-checker-eslint"
    }
  ]
}

Complex setting

The following config defines two rules. One of them is for full linting and the other is for checking pull requests. The latter sources from git diff through the built-in akitainu:git-diff-source source. Both rules have a filter set up so that @typescript-eslint/no-explicit-any erros are effective only in the latter rule.

Also this config has a custom reporter akitainu-reporter-github-pr-review which reports errors through review comments on the pull request in question.

// eslint rules to check only for changed files in PRs
const eslintAdditionalCheckRules = ["@typescript-eslint/no-explicit-any"];

module.exports = {
  rules: [
    {
      source: [
        "akitainu:static-source",
        {
          files: ["./src/**/*.ts"],
        },
      ],
      checker: "akitainu-checker-eslint",
      filter: [
        "akitainu:by-code-filter",
        {
          exclude: eslintAdditionalCheckRules,
        },
      ],
    },
    ...// additional check for pull request
    (process.env.GITHUB_BASE_REF
      ? [
          {
            source: [
              "akitainu:git-diff-source",
              {
                before: "origin/" + process.env.GITHUB_BASE_REF,
                after: "HEAD",
              },
            ],
            checker: "akitainu-checker-eslint",
            filter: [
              "akitainu:by-code-filter",
              {
                include: eslintAdditionalCheckRules,
              },
            ],
          },
        ]
      : []),
  ],
  reporters: [
    "akitainu:pretty-console-reporter",
    ...(process.env.GITHUB_TOKEN && process.env.PR_NUMBER
      ? [
          [
            "akitainu-reporter-github-pr-review",
            {
              githubToken: process.env.GITHUB_TOKEN,
              repository: "uhyo/akitainu-playground",
              prNumber: Number(process.env.PR_NUMBER),
            },
          ],
        ]
      : []),
  ],
};

See uhyo/akitainu-playground for how the above config works.

Project Status

This project is in a PoC stage. Currently only ESLint is officially supported as a checker.

Any kind of help is super welcome.

Contribution

Welcome

License

MIT