Configuring coding guidelines for GitHub Copilot code review

About coding guidelines

You can customize Copilot code review with custom coding guidelines written in natural language. For more information on Copilot code review, see "Using GitHub Copilot code review."

With coding guidelines, Copilot can give feedback based on your organization's specific coding style and best practices.

Because Copilot code review is powered by a large language model, it can help with enforcing coding guidelines that are not covered by your linter or static analysis tool.

Coding guidelines are configured at the repository level. You can create and enable up to 6 coding guidelines per repository.

Dos and don'ts for coding guidelines

• Do use simple, clear and concise language to describe your coding guideline.
• Do be as specific as possible about what Copilot should look for - that is, what you do or don't want to see in your code.
• Do take a look at the "Coding guidelines examples" below for some inspiration.
• Don't try to use coding guidelines to enforce style guidelines that can be covered by your linter or static analysis tool.
• Don't use wording that is ambiguous or could be interpreted in different ways.
• Don't try to fit multiple different ideas into a single coding guideline.

Creating a coding guideline

1. GitHub で、リポジトリのメイン ページに移動します。

2. リポジトリ名の下にある [設定] をクリックします。 [設定] タブが表示されない場合は、 [] ドロップダウン メニューを選び、 [設定] をクリックします。

   

3. In the "Code & automation" section of the side bar, click Copilot, then Code review.

4. Click Create guideline.

5. Under "Name," give the coding guideline a name.

6. Under "Description," provide a description of the coding guideline up to 600 characters long. This will be used by Copilot to understand your coding style and to decide when to leave a comment.

   How you write your description has a big impact on the quality of comments that Copilot will generate. For help with writing effective coding guidelines, see "Dos and don'ts for coding guidelines" above, and "Coding guidelines examples" below.

7. Optionally, limit the coding guideline to specific file types or paths by clicking Add file path and adding path patterns.

   You can use fnmatch syntax to define paths to target, with * as a wildcard to match any string of characters.

   GitHub では File::FNM_PATHNAME フラグを File.fnmatch 構文で使うため、* のワイルドカードがディレクトリの区切り記号 (/) と照合されません。 たとえば、qa/* は、qa/ で始まり、1 つのスラッシュを含むすべてのブランチと照合されますが、qa/foo/bar とは照合されません。 qa の後には、qa/**/* を使用して任意の数のスラッシュを含めることができます。これは、たとえば qa/foo/bar/foobar/hello-world と一致します。 qa**/**/* を使い qa の文字列を拡張して、より包括的にすることもできます。

   構文のオプションについて詳しくは、fnmatch のドキュメントを参照してください。

8. Test your coding guideline to make sure it works as expected.

   1. Click Add sample.
   2. Add your own sample, or press Generate code sample to automatically generate a code sample based on your title and description.
   3. Click Save to save the code sample.
   4. Test the coding guideline against your sample by pressing Run.

9. Save your coding guideline, and turn it on, by clicking Save guideline.

Running a review with coding guidelines

When you request a review from Copilot, it will automatically use the repository's enabled coding guidelines to review your code. For more information, see "Using GitHub Copilot code review."

Comments generated based on a coding guideline will include a message, highlighting their source.

Coding guidelines examples

Example 1: Avoid using magic numbers

Title: Avoid using magic numbers

Description: Don't use magic numbers in code. Numbers should be defined as constants or variables with meaningful names.

Path patterns: **/*.py

Example 2: Don't use SELECT * in SQL queries

Title: Don't use `SELECT *` in SQL queries

Description: Don't use `SELECT *` in SQL queries. Always specify the columns you want to select. `COUNT(*)` is allowed.

Path patterns: None (applies to all file types, as SQL queries may be embedded in code).

Example 3: Use fetch for HTTP requests

Title: Use `fetch` for HTTP requests

Description: Use `fetch` for HTTP requests, not `axios` or `superagent` or other libraries.

Path patterns: **/*.ts, **/*.js, **/*.jsx, **/*.tsx

Example 4: Always tag metrics with the current environment

Title: Always tag metrics with the current environment

Description: Always include a `env` tag with the current environment when emitting metrics, for example, `env:prod` or `env:dev`.

Path patterns: */*.go, */*.java