Run Angular tests in a container

Table of contents

Prerequisites

Complete all the previous sections of this guide, starting with Containerize Angular application.

Overview

Testing is a critical part of the development process. In this section, you'll learn how to:

Run Jasmine unit tests using the Angular CLI inside a Docker container.
Use Docker Compose to isolate your test environment.
Ensure consistency between local and container-based testing.

The docker-angular-sample project comes pre-configured with Jasmine, so you can get started quickly without extra setup.

Run tests during development

The docker-angular-sample application includes a sample test file at the following location:

$ src/app/app.component.spec.ts

This test uses Jasmine to validate the AppComponent logic.

Step 1: Update compose.yaml

Add a new service named angular-test to your compose.yaml file. This service allows you to run your test suite in an isolated, containerized environment.

 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 services:  angular-dev:  build:  context: .  dockerfile: Dockerfile.dev  ports:  - "5173:5173"  develop:  watch:  - action: sync  path: .  target: /app   angular-prod:  build:  context: .  dockerfile: Dockerfile  image: docker-angular-sample  ports:  - "8080:8080"   angular-test:  build:  context: .  dockerfile: Dockerfile.dev  command: ["npm", "run", "test"]

The angular-test service reuses the same Dockerfile.dev used for development and overrides the default command to run tests with npm run test. This setup ensures a consistent test environment that matches your local development configuration.

After completing the previous steps, your project directory should contain the following files:

├── docker-angular-sample/ │ ├── Dockerfile │ ├── Dockerfile.dev │ ├── .dockerignore │ ├── compose.yaml │ ├── nginx.conf │ └── README.Docker.md

Step 2: Run the tests

To execute your test suite inside the container, run the following command from your project root:

$ docker compose run --rm angular-test

This command will:

Start the angular-test service defined in your compose.yaml file.
Execute the npm run test script using the same environment as development.
Automatically removes the container after tests complete, using the docker compose run --rm command.

You should see output similar to the following:

Test Suites: 1 passed, 1 total Tests: 3 passed, 3 total Snapshots: 0 total Time: 1.529 s

Note
For more information about Compose commands, see the Compose CLI reference.

Summary

In this section, you learned how to run unit tests for your Angular application inside a Docker container using Jasmine and Docker Compose.

What you accomplished:

Created a angular-test service in compose.yaml to isolate test execution.
Reused the development Dockerfile.dev to ensure consistency between dev and test environments.
Ran tests inside the container using docker compose run --rm angular-test.
Ensured reliable, repeatable testing across environments without depending on your local machine setup.

Explore official references and best practices to sharpen your Docker testing workflow:

Dockerfile reference – Understand all Dockerfile instructions and syntax.
Best practices for writing Dockerfiles – Write efficient, maintainable, and secure Dockerfiles.
Compose file reference – Learn the full syntax and options available for configuring services in compose.yaml.
docker compose run CLI reference – Run one-off commands in a service container.

Next steps

Next, you’ll learn how to set up a CI/CD pipeline using GitHub Actions to automatically build and test your Angular application in a containerized environment. This ensures your code is validated on every push or pull request, maintaining consistency and reliability across your development workflow.