# Rules for pull requests and deployments

> Choose when tests run, which tests run and which address they test.

Source: https://rehearsal.dev/docs/github/rules

A rule tells Rehearsal when to run tests by itself. It answers three questions: when to run, which tests, and which address to test. The rule then reports each run as a [check on the commit](https://rehearsal.dev/docs/github/checks.md).

You need a [connected repository](https://rehearsal.dev/docs/github/connect-a-repository.md) and **Manage integrations**, which the admin and owner roles include.

## Add a rule

1. **Open the rules**

   Open **Deployments** in the sidebar and press **Rules**. Then press **Add a rule**.

2. **Choose when tests run**

   | Option | You write | It covers |
   | --- | --- | --- |
   | **When a pull request is opened or updated** | The target branch, such as `main` | Pull requests into that branch |
   | **When a branch is updated** | A branch, such as `main` | Pushes and merges to that branch |
   | **When a branch matching a pattern is updated** | A pattern, such as `release/*` | Every branch the pattern matches |

   In a pattern, `*` stands for any characters, so `release/*` matches every branch that starts with `release/`. Only a pattern may use `*`.

3. **Choose the tests**

   Pick a [suite](https://rehearsal.dev/docs/tests/suites.md), or **All approved tests**. If the project has more than one address, choose one under **Address to test**. **All approved tests** then means the approved tests of that address's app.

4. **Choose the address**

   | Option | Use it with | What Rehearsal tests |
   | --- | --- | --- |
   | **The pull request's Vercel preview** | Pull request rules | The preview Vercel builds for the pull request's newest commit |
   | **Vercel's deployment of the branch** | Branch and pattern rules | The deployment Vercel builds for the branch |
   | **The same address every time** | Branch and pattern rules | The address you write under **App address** |

5. **Save the rule**

   Press **Save rule**. The rule applies from then on.

As you answer, a sentence at the top of the page fills in. For example: "When a pull request into main opens or changes, run Checkout on its Vercel preview and report the result in GitHub."

Below the sentence is the name of the rule's check in GitHub. A pull request rule reports as `Rehearsal`. A branch rule adds its branch, such as `Rehearsal · main`.

## When tests start

| Rule | Tests start |
| --- | --- |
| Pull request, Vercel preview | When Vercel reports that the preview of the newest commit is ready. The check appears earlier, as soon as the pull request opens or changes. |
| Branch or pattern, Vercel deployment | When Vercel reports that its deployment of the branch is ready. |
| Branch or pattern, same address | As soon as someone pushes to the branch. |

[Preview deployments](https://rehearsal.dev/docs/github/preview-deployments.md) follows a pull request from start to finish.

### A fixed address

With **The same address every time**, Rehearsal tests the app as it stands when the push arrives. It cannot tell which commit the app serves, so the check says so: "Its deployed commit was not verified."

Use it for an address that always serves the branch, such as a Staging environment. To test a known commit, use a Vercel rule.

## Which tests a run checks

- A suite runs its tests. **All approved tests** runs every approved test of the app.
- The versions of those tests are fixed when the run starts. A test that changes later does not change that run.
- A suite can reach another app. If that app has more than one address, the check stops and names the app, because the rule does not say where to test it.
- When the workspace has no runs left, the check says so and no tests run.

## One rule per situation

Two rules cannot describe the same thing: the same kind of rule, on the same branch, at the same address. Rehearsal refuses the second one with **A rule already covers that branch at this address.**

## Pause, change or remove a rule

Each rule on the **Rules** page shows its sentence and its last runs.

- **Pause** stops the rule. It keeps its history and starts nothing until you press **Resume**.
- **Edit** opens the same three questions. A new branch gives the check a new name, so make that name required in GitHub again.
- **Remove** stops Rehearsal checking the branch. Runs that already finished keep their results.

## Next steps

- [Require the check](https://rehearsal.dev/docs/github/checks.md) so a pull request cannot merge until its tests pass.
- Read [what each check says](https://rehearsal.dev/docs/github/checks.md).