prefer-template-yml-extension

Rule catalog ID: R066

Targeted pattern scope

Workflow template YAML filenames under workflow-templates/.

What this rule reports

Reports template files that use .yaml instead of .yml.

Why this rule exists

Consistent file extensions improve discoverability and repository conventions.

❌ Incorrect

workflow-templates/ci.yaml

✅ Correct

workflow-templates/ci.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-template-yml-extension": "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​