prefer-action-yml

Rule catalog ID: R043

Targeted pattern scope

GitHub Action metadata files named action.yaml.

What this rule reports

Reports action metadata files that use action.yaml instead of action.yml.

Why this rule exists

GitHub supports both extensions, but the metadata docs call out action.yml as the preferred filename.

❌ Incorrect

action.yaml

✅ Correct

action.yml

Additional examples

For larger repositories, this rule is often enabled together with one of the published presets so violations are caught in pull requests before workflow changes are merged.

ESLint flat config example

import githubActions from "eslint-plugin-github-actions-2";

export default [
  {
    files: ["**/*.{yml,yaml}"],
    plugins: {
      "github-actions": githubActions,
    },
    rules: {
      "github-actions/prefer-action-yml": "error",
    },
  },
];

When not to use it

You can disable this rule when its policy does not match your repository standards, or when equivalent enforcement is already handled by another policy tool.

Targeted pattern scope​

What this rule reports​

Why this rule exists​

❌ Incorrect​

✅ Correct​

Additional examples​

ESLint flat config example​

When not to use it​

Further reading​