An example app to demonstrate some concepts and best practices:
- Developing inside a Docker container, with hot-reload.
- Example test approach.
- Use of official node Docker image.
- Docker multi-stage build.
- Use of linter and code coverage.
- Use of Makefile to build and run Docker image.
- Use of tmux for simple per-project dev orchestration.
There are some potential advantages to being able to run code in the container while developing:
- develop the code in the same environment as it will run in production.
- easily connect to other docker services, for example a database, using docker networking.
- paves the way to bringing up an entire stack of services using docker-compose.
You can of course continue to run the code directly on the host machine without docker.
The tests are strictly split between the setup and assertion of each test. This means that failing assertions are clear to understand, and new assertions can easily be added.
Using the official Docker image can be an easy way to run the application securely, and stay up to date with the latest platform features and security fixes.
The docker build is carried out using a multi-stage build process. This effectively creates two container environments, where the first container is used as a temporary build environment, and the specified artefacts of that build are carried into the second container which will become the production artefact.
In a Typescript application, this is useful as it keeps the source code out of the distributed package. Only the built code and the production node_modules will be packaged.
The linter will ensure code-style consistency.
The code coverage can provide some clues as to areas of the code that may require additional test coverage.
Provides an example of how the container should be built and run.
The commands included here could perhaps remove the need for a proper CI tool in the early stages of a project. When CI is required, the commands can just be called by the CI tool, so the CI configuration does not require any special knowledge of how to build the project other than the name of the command.
A simple script is included to run a simple and minimal "dev environment", using vim, the dev docker container and tests. Everyone will have their own preferences for how they develop, and this is merely intended to show the benefits of this project setup.
npm installis run with the--ignore-scriptsflag, which prevents dependencies and their sub-dependencies from running scripts. This removes the most serious attack vector with npm, however it may break dependencies that rely on install scripts to function. Remove this flag at your own peril.