rules

Public API

Macros and Functions

terser

Run the terser minifier.

Typical example:

load("@aspect_rules_terser//terser:defs.bzl", "terser")

terser(
    name = "out.min",
    srcs = "input.js",
    config_file = "terser_config.json",
)

Note that the name attribute determines what the resulting files will be called.

So the example above will output out.min.js and out.min.js.map (since sourcemap defaults to true).

If the input is a directory, then the output will also be a directory, named after the name attribute.

Note that this rule is NOT recursive. It assumes a flat file structure. Passing in a folder with nested folder will result in an empty output directory.

name

Required.

A unique name for this target.

node_modules

Required.

Label pointing to the linked node_modules target where the terser is linked, e.g. //:node_modules.

terser must be linked into the node_modules supplied.

srcs

Required.

File(s) to minify.

Can be .js files, a rule producing .js files as its default output, or a rule producing a directory of .js files.

If multiple files are passed, terser will bundle them together.

data

Optional. Default: []

Runtime dependencies to include in binaries/tests that depend on this target.

The transitive npm dependencies, transitive sources, default outputs and runfiles of targets in the data attribute are added to the runfiles of this target. They should appear in the '*.runfiles' area of any executable which has a runtime dependency on this target.

If this list contains linked npm packages, npm package store targets or other targets that provide JsInfo, NpmPackageStoreInfo providers are gathered from JsInfo. This is done directly from the npm_package_store_deps field of these. For linked npm package targets, the underlying npm_package_store target(s) that back the links is used. Gathered NpmPackageStoreInfo providers are propagated to the direct dependencies of downstream linked npm_package targets.

NB: Linked npm package targets that are "dev" dependencies do not forward their underlying npm_package_store target(s) through npm_package_store_deps and will therefore not be propagated to the direct dependencies of downstream linked npm_package targets. npm packages that come in from npm_translate_lock are considered "dev" dependencies if they are have dev: true set in the pnpm lock file. This should be all packages that are only listed as "devDependencies" in all package.json files within the pnpm workspace. This behavior is intentional to mimic how devDependencies work in published npm packages.

sourcemap

Optional. Default: True

Whether to produce a .js.map output

config_file

Optional. Default: "@aspect_rules_terser//terser/private:terser_config.default.json"

A JSON file containing Terser minify() options.

This is the file you would pass to the --config-file argument in terser's CLI. https://github.com/terser-js/terser#minify-options documents the content of the file. Bazel will make a copy of your config file, treating it as a template. Run bazel with --subcommands to see the path to the copied file. If you use the magic strings "bazel_debug" or "bazel_no_debug", these will be replaced with true and false respecting the value of the debug attribute or the --compilation_mode=dbg bazel flag. For example

{
    "compress": {
        "arrows": "bazel_no_debug"
    }
}

Will disable the arrows compression setting when debugging. If config_file isn't supplied, Bazel will use a default config file.

debug

Optional. Default: False

Configure terser to produce more readable output.

Instead of setting this attribute, consider using debugging compilation mode instead bazel build --compilation_mode=dbg //my/terser:target so that it only affects the current build.

args

Optional. Default: []

Additional command line arguments to pass to terser.

Terser only parses minify() args from the config file so additional arguments such as --comments may be passed to the rule using this attribute. See https://github.com/terser/terser#command-line-usage for the full list of terser CLI options.

kwargs

Optional.

Other common arguments such as tags and visibility