circleci-dart-demo

Demo repository using Dart lang by Google. Cherry-picks number_guesser and number_thinker code from Write HTTP clients & servers tutorial.

Visit the Dart language guide for CircleCI here.

Running Locally

Prerequisites

1. Make sure Dart is installed and configured on your system.
2. Install the webdev Dart package globally with pub global activate webdev.

Setup

1. Clone this project.
2. Run pub get to download dependencies.
3. pub run bin/server.dart to run the number thinker server. It listens at https://localhost:8080
4. webdev serve web:8181 in another terminal at the project root to serve the basic webpage at https://localhost:8181. It's just a basic webpage with dropdown and button to send guess API requests to the server.

Testing

1. Run pub run test to test the server and number_guesser.

Building

1. webdev build compiles the web client (just an index.html).
2. dart2native compiles the server client to machine code and spits out an executable in bin.

CircleCI

The CircleCI config does the following:

1. It runs the tests on a Docker container.
   • This job uses the google/dart Docker image (CircleCI doesn't currently have a native Dart docker convenience image).
   • The tests uses the junitreporter package to produce JUnit XML output for CircleCI's test metadata feature, which in turn supports things like test summary and insights data/metrics.
2. After tests run, it builds executables for deployment:
   • One job uses Google's recommended dart-runtime image to build a production container. There's a section that pushes to DockerHub, but that's been commented out since we don't want to unnecessarily spam our repo with example images. It's there as an example.
   • The other three jobs compile native executables on macOS, Windows, and Linux VMs.
3. All jobs use dependency caching. The jobs cache according to the pubspec.lock and the arch of the system.
   • ~/.pub-cache and .dart_tool folders are cached. ~/AppData/Local/Pub/Cache if Windows.
   • This demo project doesn't download enough dependencies to show any signficant performance benefit, but it's shown as an example. Larger projects that download many hundreds of MB of dependencies should see greater performance and speed gains.
   • For Dart projects that have it, you'll probably also want to cache the .packages folder in the project directory.
4. If you fork this project and want to push to DockerHub, this project assumes a context called dart-docker with the following variables & keys:

KEY	VALUE
DOCKER_TAG	The tag/repository for your image
DOCKER_LOGIN	Your Docker login
DOCKER_PWD	Your Docker password

See the config and modify as needed for your use case.

For more resources, see below:

• Getting Started
• Migrating to CircleCI
• Deploying on CircleCI
• Using Contexts
• Configuration Reference