E2E Tests

E2E tests enable us to verify the behavior of the packages in this repository as if they were to be published in their current state.

How to run

Prerequisites: Docker

Copy .env.example to .env
OPTIONAL: Fill in auth information in .env for an example Sentry project - you only need this to run E2E tests that send data to Sentry.
Run yarn build:tarball in the root of the repository (needs to be rerun after every update in /packages for the changes to have effect on the tests).

To finally run all of the tests:

yarn test:e2e

Or run only a single E2E test app:

yarn test:run <app-name>

How they work

Before running any tests we launch a fake test registry (in our case Verdaccio), we build our packages, pack them, and publish them to the fake registry. The fake registry is hosted in a Docker container, and the script to publish the packages is also run from within a container to ensure that the fake publishing happens with the same Node.js and npm versions as we're using in CI.

After publishing our freshly built packages to the fake registry, the E2E test script will look for test-recipe.json files in test applications located in the test-applications folder. In this folder, we keep standalone test applications, that use our SDKs and can be used to verify their behavior. The test-recipe.json recipe files contain information on how to build the test applications and how to run tests on these applications.

How to set up a new test

Test applications are completely standalone applications that can be used to verify our SDKs. To set one up, follow these commands:

cd dev-packages/e2e-tests

# Create a new test application folder
mkdir test-applications/my-new-test-application # Name of the new folder doesn't technically matter but choose something meaningful

# Create an npm configuration file that uses the fake test registry
cat > test-applications/my-new-test-application/.npmrc << EOF
@sentry:registry=http://127.0.0.1:4873
@sentry-internal:registry=http://127.0.0.1:4873
EOF

Make sure to add a test:build and test:assert command to the new app's package.json file.

Test apps in the folder test-applications will be automatically picked up by CI in the job job_e2e_tests (in .github/workflows/build.yml). The test matrix for CI is generated in dev-packages/e2e-tests/lib/getTestMatrix.ts.

For each test app, CI checks its dependencies (and devDependencies) to see if any of them have changed in the current PR (based on nx affected projects). For example, if something is changed in the browser package, only E2E test apps that depend on browser will run, while others will be skipped.

You can add additional information about the test (e.g. canary versions, optional in CI) by adding sentryTest in the package.json of a test application.

An important thing to note: In the context of the build/test commands the fake test registry is available at http://127.0.0.1:4873. It hosts all of our packages as if they were to be published with the state of the current branch. This means we can install the packages from this registry via the .npmrc configuration as seen above. If you add Sentry dependencies to your test application, you should set the dependency versions set to latest || * in order for it to work with both regular and prerelease versions:

// package.json
{
  "name": "my-new-test-application",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "test": "echo \"Hello world!\"",
    "test:build": "pnpm install",
    "test:assert": "pnpm test"
  },
  "dependencies": {
    "@sentry/node": "latest || *"
  }
}

All that is left for you to do now is to create a test app and run yarn test:e2e.

Standardized Test Apps

For some of our E2E tests we define a standard for test applications as to how they should look and behave. Standardized test apps enables us to reuse the same test suite over a number of different frameworks/SDKs.

Standardized Frontend Test Apps

TODO: This is not up to date.

A standardized frontend test application has the following features:

Just for the sake of consistency we prefix the standardized frontend tests with standard-frontend-. For example standard-frontend-nextjs.
A page at path /
- Having a <input type="button" id="exception-button"> that captures an Exception when clicked. The returned eventId from the Sentry.captureException() call must be written to window.capturedExceptionId. It does not matter what the captured error looks like.
- Having an link with id="navigation" that navigates to /user/5. It doesn't have to be an <a> tag, for example if a framework has another way of doing routing, the important part is that the element to click for navigation has the correct id. Text of the link doesn't matter.
An empty page at /user/5

Apps should write all pageload and navigation transaction IDs into an array at window.recordedTransactions. This can be done with an event processor:

Sentry.addEventProcessor(event => {
  if (
    event.type === 'transaction' &&
    (event.contexts?.trace?.op === 'pageload' || event.contexts?.trace?.op === 'navigation')
  ) {
    const eventId = event.event_id;
    window.recordedTransactions = window.recordedTransactions || [];
    window.recordedTransactions.push(eventId);
  }

  return event;
});

Standardized Backend Test Apps

TBD

Uh oh!