node-rules

A Node.js toolchain for the Please build system.

This plugin does one thing: fetch a Node.js distribution for the host platform and expose node, npm, npx and corepack as entry points. It has no opinions about JavaScript, so a ruleset that needs a hermetic node can depend on it without inheriting a build system for JS.

Install

Add the plugin in plugins/BUILD:

plugin_repo(
name="node",
owner="becomeliminal",
plugin="node-rules",
revision="v0.1.0",
)

Register it in .plzconfig:

[Plugin "node"]Target = //plugins:node

Declare a toolchain in third_party/node/BUILD:

subinclude("///node//build_defs:node")
node_toolchain(
name="node",
)

Then point the plugin config at it, so rules can find it:

[Plugin "node"]Target = //plugins:node
NodeTool = //third_party/node:node|node
NpmTool = //third_party/node:node|npm

Using it in a rule

node is a real binary and runs standalone. npm, npx and corepack are JavaScript, so they are run through node:

subinclude("///node//build_defs:node")
build_rule(
name="example",
outs= ["out.txt"],
cmd="$TOOLS_NODE $TOOLS_NPM --version > $OUT",
tools= {
"node": [CONFIG.NODE.NODE_TOOL],
"npm": [CONFIG.NODE.NPM_TOOL],
},
)

The subinclude is required in every BUILD file that reads CONFIG.NODE, not only in ones calling node_toolchain — the config namespace is scoped to files that have loaded the plugin. A downstream ruleset gets this for free by subincluding ///node//build_defs:node from its own build_defs.

The Node.js tarball ships bin/npm as a symlink to a .js file carrying a #!/usr/bin/env node shebang, so invoking bin/npm directly resolves node from $PATH — silently using the host's node where there is one, and failing where there is not. The entry points therefore name the scripts themselves, and the downloaded tree is left byte-identical to what nodejs.org shipped.

Configuration

Config key	Default	Meaning
NodeTool	///node//third_party/node:node|node	Build label for the node binary
NpmTool	///node//third_party/node:node|npm	Build label for the npm CLI
DefaultVersion	22.23.2	Version used when node_toolchain is called without one

Versions

node_toolchain carries pinned SHA256 hashes for each supported release, so callers pass a version and never a hash:

node_toolchain(
name="node",
version="22.23.2",
)

Hashes come from https://nodejs.org/dist/v<version>/SHASUMS256.txt and live in the generated block at the top of build_defs/node.build_defs. To use a release that is not pinned, pass hashes explicitly.

Supported platforms: linux-x64, linux-arm64, darwin-x64, darwin-arm64.