docs/.github/copilot-instructions.md

This repository contains code to run the GitHub Docs site on docs.github.com, as well as the content that is displayed on the site. The code is written in JavaScript and TypeScript, and the content is primarily written in Markdown.

Changes to files in src/* or files with .ts or .js extensions are likely code-related changes. Please follow the engineering guidelines below when making changes to these files.

Changes to files in content/* and data/* are likely content-related changes. Content changes include updates to articles, reusable content, and data files that define variables used in articles. Please follow the content guidelines below when making changes to these files.

Engineering guidelines

Scripts

All scripts can be found in package.json.

To validate any code changes:

• npm run tsc
• npm run build
• npm run prettier
• npm run lint: you can include -- --fix

To validate specific changes,

• npm run test: For all unit tests
  • You can pass specific paths, e.g. npm run test -- src/search/tests/ai-search-proxy
  • You can add --silent=false to include console.log debugging.
• npm run build && npm run playwright-test -- playwright-rendering: You need to build for changes outside of the test to be picked up. We use playwright for all rendering and end-to-end tests
  • You can add --ui to keep open localhost:4000 which can be viewed in a simple browser for debugging UI state.
• npm run dev to start the development server on localhost:4000.

Imports

We use absolute imports, relative to the src directory, using the @ symbol.

For example, getRedirect which lives inn src/redirects/lib/get-redirect.js can be imported with import getRedirect from '@/redirects/lib/get-redirect'.

The same rule applies for TypeScript (.ts) imports, e.g. import type { GeneralSearchHit } from '@/search/types'

Testing changes

We use vitest to write unit tests. Tests live in their own files in the tests subdirectory of a source (src) directory, e.g. src/search/tests/api-ai-search.ts.

For integration tests, we can use the mock server in src/tests/mocks/start-mock-server.ts to mock exteneral requests.

For UI rendering tests, we use playwright and write tests in src/fixtures/tests/playwright-rendering.spec.ts

Content guidelines

Bullet lists

The bulleted points in a bullet list should always be denoted in Markdown using an asterisk, not a hyphen.

Using variables

Within Markdown files, with the exception of the title field in the metadata at the start of a file, always use the Liquid syntax variables rather than text if a variable has been defined for that text. This ensures consistency and makes it easier to update product names globally.

Important: Variables must be used in all content, including reusable content, data files, and regular articles. The only exceptions are the title field in frontmatter metadata and any file in the content/site-policy directory.

For example:

Use this variable	Don't use this text	File where variable is defined
{% data variables.product.github %}	GitHub	data/variables/product.yml
{% data variables.product.prodname_ghe_server %}	GitHub Enterprise Server	data/variables/product.yml
{% data variables.product.prodname_copilot_short %}	Copilot	data/variables/product.yml
{% data variables.product.prodname_copilot %}	GitHub Copilot	data/variables/product.yml
{% data variables.copilot.copilot_code-review_short %}	Copilot code review	data/variables/copilot.yml
{% data variables.enterprise.prodname_managed_user %}	managed user account	data/variables/enterprise.yml
{% data variables.code-scanning.codeql_workflow %}	CodeQL analysis workflow	data/variables/code-scanning.yml

There are many more variables. These are stored in various YAML files within the data/variables directory.

How to find variables: Check the data/variables directory for existing variables before writing hardcoded text. Common variable files include:

• data/variables/product.yml - Product names and variations
• data/variables/copilot.yml - Copilot-specific terms
• data/variables/enterprise.yml - Enterprise-specific terms
• data/variables/code-scanning.yml - Code scanning terms

Reusable text

Reusables are long strings of reusable text, such as paragraphs or procedural lists, that are referenced in multiple content files. This makes it easier for us to maintain content and ensure that it is accurate across all files where the content is needed.

Each reusable lives in its own Markdown file. The path and filename of each reusable determines what its path will be in the data object. For example, a file named /data/reusables/foo/bar.md will be accessible as {% data reusables.foo.bar %} in articles.

Examples where you should create a reusable:

• You are documenting a new feature for a public preview. You need to create a note to display in all new articles about the new feature. Create a new reusable for the note and use it in all articles where it is needed.
• You are documenting billing for a new feature and need to briefly mention how the feature is billed and link to content about billing in several articles. Create a new reusable with the brief mention and a link to the content on billing. Aim to use the reusable in all places where you want to mention billing for the feature.

Links to other articles

[AUTOTITLE] is the only correct way to specify the title of a linked article when that article is another page on the docs.github.com site.

You can replace the placeholder link text [AUTOTITLE] only when linking to an anchor in the same article or when linking to an anchor in another article and the actual article title would be confusing.

Never use the {% link %} Liquid tag for internal documentation links. The [AUTOTITLE] placeholder automatically pulls the correct title and ensures links remain valid when titles change.

Examples:

• ✅ Correct: For more information, see [AUTOTITLE](/copilot/using-github-copilot).
• ❌ Incorrect: For more information, see [Using GitHub Copilot](/copilot/using-github-copilot).
• ❌ Incorrect: For more information, see {% link /copilot/using-github-copilot %}.

Parenthetical dashes

Where a sentence of normal body text contains a parenthetical dash, the dash should always be an em dash without spaces at either side. This rule does not apply to text within code blocks.

Examples:

• ✅ Correct: "The cat—which sat on a branch—smiled with a broad grin." (em dash without spaces)
• ❌ Incorrect: "The cat — which sat on a branch — smiled with a broad grin." (em dash with spaces)
• ❌ Incorrect: "The cat–which sat on a branch–smiled with a broad grin." (en dash without spaces)
• ❌ Incorrect: "The cat – which sat on a branch – smiled with a broad grin." (en dash with spaces)
• ❌ Incorrect: "The cat-which sat on a branch-smiled with a broad grin." (hyphen without spaces)
• ❌ Incorrect: "The cat - which sat on a branch - smiled with a broad grin." (hyphen with spaces)

Creating a pull request

When creating a pull request as a result of a request to do so in Copilot Chat, the first line of the PR description should always be the following (in italics):

_This pull request was created as a result of the following prompt in Copilot Chat._

Then, within a collapsed section, quote the original prompt from Copilot Chat:

<details>
<summary>Original prompt - submitted by @GITHUB-USER-ID</summary>

> [Original prompt text here]

</details>

This helps reviewers understand the context and intent behind the automated changes.

Testing Content changes

Before committing content changes, always:

1. Use the content linter to validate content: npm run lint-content -- --paths <file-paths>
2. Check for proper variable usage in your content
3. Verify [AUTOTITLE] links point to existing articles
4. Run tests on changed content: npm run test -- src/content-render/tests/render-changed-and-deleted-files.js