Running Unit Tests and Integration Tests - CircleCI Tutorial

Introduction

Unit tests and integration tests are essential for ensuring the quality and reliability of your code. CircleCI provides a seamless way to run tests within your CI/CD pipeline, allowing you to automate the testing process and catch bugs early. This tutorial will guide you through the process of running unit tests and integration tests in CircleCI.

Example

Let's consider an example where we run unit tests and integration tests for a Node.js application:


    version: 2.1

    jobs:

      test:

        docker:

          - image: circleci/node:12

        steps:

          - checkout

          - restore_cache:

            keys:

              - v1-dependencies-{{ checksum "package-lock.json" }}

          - run: npm install

          - save_cache:

            paths:

              - ./node_modules

            key: v1-dependencies-{{ checksum "package-lock.json" }}

          - run:

            name: Run Unit Tests

            command: npm run test:unit

          - run:

            name: Run Integration Tests

            command: npm run test:integration

Running Unit Tests and Integration Tests

To run unit tests and integration tests in CircleCI, follow these steps:

1. Define your test suite

Create a test suite that includes both unit tests and integration tests. Unit tests focus on testing individual components or functions in isolation, while integration tests validate the interaction between different components or systems.

2. Configure CircleCI

Create a configuration file (e.g., .circleci/config.yml) in your project repository to define the CI/CD pipeline. Specify the necessary steps to set up the environment, install dependencies, and execute the tests. Use the appropriate Docker image or environment that matches your project's requirements.

Here's an example configuration that runs unit tests and integration tests for a Node.js application:


    version: 2.1

    jobs:

      test:

        docker:

          - image: circleci/node:12

        steps:

          - checkout

          - restore_cache:

            keys:

              - v1-dependencies-{{ checksum "package-lock.json" }}

          - run: npm install

          - save_cache:

            paths:

              - ./node_modules

            key: v1-dependencies-{{ checksum "package-lock.json" }}

          - run:

            name: Run Unit Tests

            command: npm run test:unit

          - run:

            name: Run Integration Tests

            command: npm run test:integration

Common Mistakes

Not including a comprehensive test suite that covers both unit tests and integration tests
Missing or incorrect configuration for test dependencies
Incorrectly configuring the test commands or scripts

Frequently Asked Questions (FAQs)

Can I run tests in parallel in CircleCI?

Yes, CircleCI supports parallelism, allowing you to split your test suite into multiple jobs or utilize parallel execution within a single job. This can significantly reduce test execution time.
Can I generate test reports in CircleCI?

Yes, many test frameworks provide built-in functionality or plugins to generate test reports. You can configure your CI/CD pipeline to capture and store these reports as artifacts, making it easier to analyze the test results.
How can I control the behavior of tests in CircleCI?

You can customize the test behavior by modifying the test commands or scripts in your CircleCI configuration file. For example, you can pass environment variables, specify test configurations, or run specific subsets of tests.

Summary

In this tutorial, you learned how to run unit tests and integration tests in CircleCI to validate the functionality and integrity of your code. By defining a comprehensive test suite, configuring CircleCI, and executing the tests within your CI/CD pipeline, you can automate the testing process and catch issues early. Avoid common mistakes, regularly update and expand your test suite, and optimize test execution for better efficiency. Refer to the CircleCI documentation and the documentation of your chosen test frameworks for further details and advanced configuration options.