This is a plugin to integrate Node/NPM with Pants.
You can specify node_remote_module targets referring to remote 3rd party Node modules, and you can specify node_module targets defining projects in the source tree.
node_module targets can depend on node_remote_module targets in the "dependencies" field of their specification in a BUILD file. A node_module target will work with a package.json source file in the same directory, combining the BUILD dependencies with the additional fields from the source package.json to form the complete package.json used for tasks on the target.
The way this currently works is, when resolving a target, Pants drops the dependencies, devDependencies, peerDependencies and optionalDependencies fields from the target's corresponding package.json file, and installs with a dependencies field populated from the BUILD file target dependencies. This has the benefit of letting Pants work with an existing package.json file for a project that can be installed via "npm install" without Pants. However a project that takes advantage of this ability to be installed via a normal "npm install" in the source tree would need its dependencies duplicated in the BUILD target and package.json file. Obviously this is not desirable. Over time, Pants support for NPM should improve to work with a fully functional package.json with no duplication of information in the BUILD file.
Utility is still limited right now.
Pants will bootstrap itself with its own copy of Node and NPM and use them to run commands. It runs those commands with the bootstrapped Node's bin directory at the front of the PATH.
Pants can install remote and local Node modules into the .pants.d working directory with "./pants resolve [target]".
You can resolve node_remote_module and node_module targets. Pants effectively walks forward from the edges of the dependency tree topological sort for a target and does an "npm install" for each target it encounters along the way. node_module targets have their sources copied into place under the working directory. node_remote_module dependencies are installed from the remote source, and node_module dependencies are installed via paths to previously-installed targets under the working directory.
"./pants repl [target]" lets you run Node in REPL mode from the resolved target's path under the working directory.
The examples directory contains a few types of interdependent JS projects.
- A server project transpiled using Babel in its prepublish step
- A web build tool encapsulating Webpack and a set of loaders
- A web component (button) using React and CSS in a separate file, built with the web build tool, containing its own test file
- A web project using React, built with the web build tool, depending on the server project and button component, and containing its own test file
Resolving the server project produces a dist directory with code transpiled by Babel, in addition to the project sources, in the target's directory under .pants.d.
The other projects are designed to eventually demonstrate building code with the web build tool project via "npm run build" and testing (including a pre-test build step) via "npm test", once the ability to run scripts from a target is implemented.