Run Angular tests in a container

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.

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.

Related resources

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.