DevCmd - Development Commands in Node.js and TypeScript

What is DevCmd?

• Automation: Improve your development life, speed up recurring tasks, and reduce errors by automating your development tasks like building, running tests, or bumping versions.
• Library: DevCmd gives you the tools to make automation simpler, such as easily running external programs (in series or in parallel) or composing smaller commands into more powerful ones.
• Launcher: With the included devcmd launcher, you can easily start your commands with yarn devcmd or npx devcmd. Additionally, you can globally install devcmd-cli to use the launcher directly and from anywhere.
• TypeScript & JavaScript: Benefit from the power of the npm ecosystem. Use the safety and abstraction of TypeScript where it helps you. Drop to plain JavaScript when you want to.

Getting Started

• Install the devcmd package in your workspace:

  $ yarn add -D devcmd
  # - or -
  $ npm install -D devcmd

• If you want to write commands in TypeScript, you also need typescript and ts-node. If you don't already have these installed, do so now:

  $ yarn add -D typescript ts-node
  # - or -
  $ npm install -D typescript ts-node

• Create a directory named "dev_cmds" in your workspace (this name is required).

• Create your commands in this "dev_cmds" directory.

  • The file name (without the extension) is the command name.

  • Each command is run as a standalone script, so top-level statements are permissible. When you want to use Promises (async/await), you need to take care of top-level Promise rejections as well.

  • For example, to create a "build" command, add a file "dev_cmds/build.ts" with the following content (or "dev_cmds/build.js" and drop the type definitions):

    // TypeScript
    import { execPiped, execPipedParallel, runAsyncMain } from "devcmd";
    
    export async function example() {
      console.log("Example command for single-package-json example");
    
      await execPiped({
        command: "node",
        args: ["-v"],
      });
    
      await execPipedParallel({
        nodeVersion: {
          command: "node",
          args: ["-v"],
        },
        npmVersion: {
          command: "npm",
          args: ["--version"],
        },
      });
    }
    
    runAsyncMain(example);

• You can now run your commands with the locally installed devcmd CLI. We recommend using yarn or npx to invoke it:

  $ yarn devcmd <script name> [<args of you scripts>...]
  # - or -
  $ npx devcmd <script name> [<args of you scripts>...]

  • For example, to run the "build" command from above:

    $ yarn devcmd build
    # - or -
    $ npx devcmd build

• If you don't want to type yarn/npx every time, you can globally install devcmd-cli (see below).

Using the Global Launcher: devcmd-cli

devcmd-cli is a command line utility to launch your dev commands that is intended to be installed globally:

$ yarn global add devcmd-cli
# - or -
$ npm install --global devcmd-cli

Once installed, running devcmd looks for the closest "dev_cmds" directory and starts command you entered with the locally installed devcmd package there. This way, you don't have to synchronize the versions of DevCmd you are using in different projects, and you can use the global launcher with a wide range of devcmd versions.

Going back to the example "build" command from above, you can now run it from the project directory or any subdirectories with:

$ devcmd build

Setting up a local development setup

It is recommended to use the Remote-Containers extension for Visual Studio Code for this. Once the extension is installed, click Reopen in Container within the popup in the bottom right or open the command palette and run the command Remote-Containers: Reopen in Container.

Since both the devcmd and the devcmd-cli packages use local installations within node_modules folders, developing and especially testing devcmd locally can be challenging. In order to setup a local development environment, you can use the devcmd task setup-dev, which intializes a dev-folder, that contains the required devcmd-package as a yarn symlink.

$ yarn devcmd setup-dev
# - or -
$ npx devcmd setup-dev

You can now change the devcmd and the devcmd-cli packages. In order to test your changes, build the packages and run devcmd in the generated dev folder.

# Build all packages
$ yarn devcmd build-all
# - or -
$ npx devcmd build-all

# You can also build a package seperately
$ yarn workspace <package> build

# Run devcmd in the dev environment using the utility script in the package.json
$ yarn dev [PARAMS]
# - or -
$ npm run dev [PARAMS]

# Alternatively you can run devcmd from within the dev folder
$ cd dev
/dev $ yarn devcmd [PARAMS]
# - or -
/dev $ npx devcmd [PARAMS]

To properly cleanup the folder and the symlinks, use the devcmd task clean-dev.

$ yarn devcmd clean-dev
# - or -
$ npx devcmd clean-dev