Vitest Integration with Mergify

This guide explains how to integrate Vitest with Test Engine using the @mergifyio/vitest reporter. Once installed, test results are automatically uploaded to Test Engine without any extra workflow changes.

• Node.js 22 or later in the job that runs the tests. Older versions are not supported: npm and pnpm only warn at install, Yarn 1 refuses, and at run time the reporter reports nothing and prints no Mergify line.

• Vitest 3 or later.

Install the @mergifyio/vitest package alongside vitest to automatically upload your test results to Test Engine.

Use the package manager version your project pins (packageManager in package.json, mise.toml, .tool-versions), and check that the lockfile diff only adds the new packages: another version rewrites unrelated entries (older npm releases, for example, drop the libc fields of other packages; npx npm@latest install … avoids it).

npm install --save-dev @mergifyio/vitest

yarn add --dev @mergifyio/vitest

pnpm add --save-dev @mergifyio/vitest

Add the Mergify reporter to the file your Vitest settings already live in: vitest.config.*, or the test section of vite.config.*. Do not create a vitest.config.* next to a vite.config.* that holds them: Vitest then reads only the new file and drops your settings. With no configuration file at all, create vitest.config.ts.

import { defineConfig } from 'vitest/config';
import MergifyReporter from '@mergifyio/vitest';

export default defineConfig({
  test: {
    reporters: [
      'default',
      ...(process.env.GITHUB_ACTIONS === 'true' ? ['github-actions'] : []),
      new MergifyReporter(),
    ],
  },
});

If your Vitest configuration is loaded as CommonJS (no "type": "module" in package.json, and not a .mts file), or TypeScript reports a type conflict between two vitest copies on new MergifyReporter(), reference the reporter by its package name instead: '@mergifyio/vitest'. Importing it into a CommonJS configuration makes every suite fail to load.

Setting reporters replaces Vitest’s defaults. When your configuration did not set reporters before, keep them as above: 'default' for the console output, and 'github-actions' on GitHub Actions for the failure annotations on pull requests. When it did, add new MergifyReporter() to your existing list.

With test.projects, every project runs under the same job name. Two projects that run the same test files (for example once in Node.js and once in a browser) report each test twice under one identity: run them in separate CI jobs or steps, each with its own MERGIFY_TEST_JOB_NAME.

The plugin uploads results only when the CI environment variable is set, or when MERGIFY_CI_ENABLE is on. GitHub Actions, CircleCI and Buildkite set CI for you. Jenkins does not: set CI=true, or MERGIFY_CI_ENABLE=true, in the stage that runs your tests. If your tests behave differently when CI is set (some test suites skip or add tests on CI), set MERGIFY_CI_ENABLE=true instead of CI, so the tests that run stay the same.

CI counts as set unless it is empty or a false value (false, no, off, 0, f or n), so true, 1 and a CI system’s name (Woodpecker sets CI to woodpecker) all count. MERGIFY_CI_ENABLE is stricter: only true, yes, on, 1, t or y turn it on. Case does not matter for either.

Without MERGIFY_TOKEN the plugin uploads nothing and your tests run as usual. Pull requests from forks and Dependabot pull requests on GitHub Actions get no repository secrets, so they report nothing: no guard is needed in the workflow. (The RSpec gem logs an authentication error when the variable is set but empty, as on those pull requests; the tests are not affected.) To have Dependabot pull requests report too, store the key as a Dependabot secret as well (gh secret set MERGIFY_TOKEN --app dependabot --repo <owner>/<repository>).

Every test is identified by its name and the name of the CI job that ran it. By default the job name is the job’s identifier in your CI:

Set MERGIFY_TEST_JOB_NAME when that default is not one stable name per set of tests:

• GitHub Actions matrix: every leg shares one job id. Set it per leg from the matrix values, for example MERGIFY_TEST_JOB_NAME: test (${{ matrix.python-version }}, ${{ matrix.os }}).

• Two test runs in one job: set a distinct name on each step.

• Reusable workflows: a called workflow reports under the caller’s workflow name, so two called workflows whose jobs share an id (often test) collide. Set a distinct name in each.

• Jenkins multibranch pipelines: each branch and each pull request keeps its own test history, and no setting changes that. JOB_NAME includes the branch or pull request (my-repo/PR-123) and is also the pipeline name tests are filed under; MERGIFY_TEST_JOB_NAME replaces only the job name. Do not set it for this purpose.

• Shards of one test suite are the same tests split across machines: give all shards the same name. Never put a shard index in it.

tox, docker run and Docker Compose start the tests in an environment that does not inherit the CI job’s variables. Pass through MERGIFY_TOKEN, CI, MERGIFY_TEST_JOB_NAME if you set it, and every variable the plugin reads to identify the run. tox’s pass_env accepts globs (GITHUB_*); Docker Compose, docker run -e and the Buildkite Docker Compose plugin need each name:

GitHub Actions: GITHUB_ACTIONS GITHUB_BASE_REF GITHUB_EVENT_NAME GITHUB_EVENT_PATH
  GITHUB_HEAD_REF GITHUB_JOB GITHUB_REF_NAME GITHUB_REF_TYPE GITHUB_REPOSITORY
  GITHUB_REPOSITORY_ID GITHUB_RUN_ATTEMPT GITHUB_RUN_ID GITHUB_SERVER_URL
  GITHUB_SHA GITHUB_WORKFLOW RUNNER_NAME
CircleCI: CIRCLECI CIRCLE_BRANCH CIRCLE_BUILD_URL CIRCLE_JOB
  CIRCLE_REPOSITORY_URL CIRCLE_SHA1 CIRCLE_WORKFLOW_ID
Buildkite: BUILDKITE BUILDKITE_AGENT_NAME BUILDKITE_BRANCH BUILDKITE_BUILD_ID
  BUILDKITE_BUILD_URL BUILDKITE_COMMIT BUILDKITE_LABEL BUILDKITE_PIPELINE_SLUG
  BUILDKITE_PULL_REQUEST BUILDKITE_PULL_REQUEST_BASE_BRANCH BUILDKITE_REPO
  BUILDKITE_RETRY_COUNT BUILDKITE_STEP_KEY
Jenkins: JENKINS_URL BUILD_ID BUILD_URL JOB_NAME NODE_NAME GIT_URL GIT_BRANCH
  GIT_COMMIT CHANGE_TARGET

Pass them by name, never by writing a value into a file. In a container on GitHub Actions, also mount the file GITHUB_EVENT_PATH points to, at the same path: without it the run is recorded against the merge commit instead of the pull request’s head commit.

Depending on its version and persona, zizmor can report secrets-outside-env on the MERGIFY_TOKEN: ${{ secrets.MERGIFY_TOKEN }} line. Run the repository’s own zizmor configuration on the changed workflow, and if it reports the finding, follow the convention the repository already uses for it: a deployment environment on the job, or an inline # zizmor: ignore[secrets-outside-env] comment.

Your workflow should run your tests as usual while exporting the secret MERGIFY_TOKEN as an environment variable.

Add the following to the GitHub Actions step running your tests:

env:
  MERGIFY_TOKEN: ${{ secrets.MERGIFY_TOKEN }}

For example:

- name: Run Tests 🧪
  env:
    MERGIFY_TOKEN: ${{ secrets.MERGIFY_TOKEN }}
  run: npm test

Set MERGIFY_TOKEN in the environment of the agents running your tests. The step itself then needs no Mergify-specific configuration:

steps:
  - label: "Run Tests 🧪"
    command: npm test

The reporter automatically collects your test results and sends them to Test Engine.

The reporter applies quarantine from a setup file it adds to each of your projects, which extends the runner Vitest builds for that project. When a quarantined test fails, that extension records it as passed, so it does not change Vitest’s exit code. The exit code of your test step already accounts for quarantine, so the step needs nothing more:

• Do not add continue-on-error: true. The recipes that upload a JUnit report with the mergifyio/gha-mergify-ci action need it because the action decides the job’s result after the tests. Here nothing does, so it would let every real failure through.

• There is no step id to set and no test_step_outcome to pass: both belong to that action, which this setup does not use.

Quarantine applies in every shape a Vitest run takes: a single Node configuration, each project under test.projects (test.workspace before Vitest 3.2), browser mode, and a custom pool such as @cloudflare/vitest-pool-workers. A runner of your own keeps running underneath.

A crash cannot pass for a green run either. Quarantine only covers failing tests. Errors that Vitest reports outside a test result, such as an unhandled error or a test file that fails to load, still make it exit non-zero and fail the step, and so does Vitest dying mid-run. The reporter uploads results when the test run ends, so a process killed outright before then, such as by the out-of-memory killer, sends nothing to Test Engine.

If the reporter cannot fetch the quarantine list, it quarantines nothing for that run, and a quarantined test that fails makes the step fail as usual.

The reporter reruns tests within the budgets set under Native Flaky Detection:

• On a pull request, a test the target branch does not have yet is new. Once the run is over, the reporter starts a Vitest run of its own that loads your configuration file, runs each file that holds a new test again in full, and repeats only those tests, as many times as fit in the Prevention Budget. When one of those runs fails, the test is flaky and the run fails, so the pull request does not merge. Vitest has printed its own summary by then, so it lists that test as passed: the reporter’s Mergify CI section names it. See Prevention.

• On a push, the reporter reruns the tests Test Engine knows as unhealthy, within the Detection Budget, to report whether they still are. The run’s result does not change. See Rerunning unhealthy tests.

Those reruns need Node.js and your configuration file. A browser project, a pool that cannot load native modules such as @cloudflare/vitest-pool-workers, and a run configured only through Vitest’s API are left out of flaky detection; quarantine still applies to all of them. The Mergify CI section says which projects were left out.

The reporter uploads each run’s results under your CI job’s name. On GitHub Actions, that name is the job’s identifier (GITHUB_JOB, recorded with the workflow name), which every leg of a matrix shares. The job name is part of a test’s identity in Test Engine, so when the legs run the same suite on several Node.js versions, their results merge into one test.

Set MERGIFY_TEST_JOB_NAME on each leg and include the matrix value, so each leg reports under its own name:

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [22, 24]
    steps:
      # ...
      - name: Run Tests 🧪
        env:
          MERGIFY_TOKEN: ${{ secrets.MERGIFY_TOKEN }}
          MERGIFY_TEST_JOB_NAME: test (node ${{ matrix.node-version }})
        run: npm test

If you split the suite with Vitest’s --shard, leave the shard index out of the name: the shards run different tests, and a test can move to another shard when tests are added or removed, so a name per shard would split its history.

Setting MERGIFY_TEST_JOB_NAME on a job that already reports changes its name, so its tests start a new history in Test Engine.

After pushing these changes, your next CI run reports its Vitest results automatically.

You can then review your test results, including any failures or flaky tests, directly in the Test Engine dashboard.

To check the setup without uploading anything, run your tests with MERGIFY_CI_ENABLE=true MERGIFY_CI_DEBUG=true: the reporter prints the spans it would send.