@bazel/terser

Terser rules for Bazel

The Terser rules run the Terser JS minifier with Bazel.

Wraps the Terser CLI documented at https://github.com/terser-js/terser#command-line-usage

Installation

Add the @bazel/terser npm package to your devDependencies in package.json.

Installing with self-managed dependencies

If you didn't use the yarn_install or npm_install rule, you'll have to declare a rule in your root BUILD.bazel file to execute terser:

# Create a terser rule to use in terser_minified#terser_bin
# attribute when using self-managed dependencies
nodejs_binary(
    name = "terser_bin",
    entry_point = "//:node_modules/terser/bin/uglifyjs",
    # Point bazel to your node_modules to find the entry point
    node_modules = ["//:node_modules"],
)

terser_minified

USAGE

terser_minified(name, args, config_file, debug, sourcemap, src, terser_bin)

Run the terser minifier.

Typical example:

load("@npm//@bazel/terser:index.bzl", "terser_minified")

terser_minified(
    name = "out.min",
    src = "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.

ATTRIBUTES

name

(Name, mandatory): A unique name for this target.

args

(List of strings): 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.

Defaults to []

config_file

(Label): 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.

Defaults to //@bazel/terser:terser_config.default.json

debug

(Boolean): 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.

Defaults to False

sourcemap

(Boolean): Whether to produce a .js.map output

Defaults to True

src

(Label, mandatory): File(s) to minify.

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

Note that you can pass multiple files to terser, which it will bundle together. If you want to do this, you can pass a filegroup here.

terser_bin

(Label): An executable target that runs Terser

Defaults to //@bazel/terser/bin:terser

Changelog

3.0.0-rc.0 (2020-12-11)

Bug Fixes

• builtin: --nobazel_run_linker implies --bazel_patch_module_resolver (7100277)
• remove jasmine-core as a peer dep (#2336) (bb2a302)
• builtin: give a longer timeout for _create_build_files (5d405a7), closes #2231
• builtin: give better error when linker runs on Node <10 (b9dc2c1), closes #2304
• builtin: make linker deterministic when resolving from manifest & fix link_workspace_root with no runfiles (f7c342f)
• examples: fix jest example on windows (3ffefa1), closes #1454
• exmaples/nestjs: add module_name field in ts_library (3a4155c)
• typescript: don't depend on protobufjs, it's transitive (1b344db)
• typescript: fail the build when ts_project produces zero outputs (3ca6cac), closes #2301
• npm_package.pack on Windows should not generate undefined.tgz (715ad22)
• typescript: specify rootDir as absolute path (535fa51)
• npm_package.pack should work in windows os (503d6fb)
• typescript: don't include _valid_options marker file in outs (570e34d), closes #2078

chore

• move karma_web_test to concatjs (#2313) (252b8e5)
• remove old stamping (68b18d8), closes #2158

Code Refactoring

• bazel_patch_module_resolver default to false (fdde32f), closes #1440 #2125
• make pkg_web#move_files private (815a3ca)

Features

• builtin: flip the default of the strict_visibility flag on the npm and yarn install rules to True (2c34857)
• concatjs: ts_devserver -> concatjs_devserver; move to @bazel/concatjs (baeae89), closes #1082
• cypress: remove browiserify preprocessor (98ee87d)
• examples: adds example for running jest with typescript (#2245) (d977c73)
• node_repositories: Added auth option for downloading nodejs and yarn (c89ff38)
• typescript: add allow_js support to ts_project (91a95b8)
• typescript: worker mode for ts_project (#2136) (5d70997)

Performance Improvements

• cypress: pack cypress runfiles into a single tar (e8484a0)

BREAKING CHANGES

• By default, we no longer patch the require() function, instead you should rely on the linker to make node modules resolvable at the standard location if this breaks you, the quickest fix is to flip the flag back on a nodejs_binary/nodejs_test/npm_package_bin with templated_args = ["--bazel_patch_module_resolver"], see https://github.com/bazelbuild/rules_nodejs/pull/2344 as an example. Another fix is to explicitly use our runfiles helper library, see https://github.com/bazelbuild/rules_nodejs/pull/2341 as an example.
• packages/karma:package.bzl is gone, in your WORKSPACE replace

load("//packages/karma:package.bzl", "npm_bazel_karma_dependencies")

npm_bazel_karma_dependencies()

with the equivalent

http_archive(
    name = "io_bazel_rules_webtesting",
    sha256 = "9bb461d5ef08e850025480bab185fd269242d4e533bca75bfb748001ceb343c3",
    urls = ["https://github.com/bazelbuild/rules_webtesting/releases/download/0.3.3/rules_webtesting.tar.gz"],
)

Then in BUILD files replace load("@npm//@bazel/karma:index.bzl", "karma_web_test_suite") with load("@npm//@bazel/concatjs:index.bzl", "concatjs_web_test_suite")

finally drop npm dependencies on @bazel/karma and depend on @bazel/concatjs instead

• concatjs_web back to karma_web
• typescript: any ts_project rule that produces no outputs must be fixed or removed
• pkg_web#move_files helper is now a private API
• • rollup_bundle config_file no longer has substitutions from a "bazel_stamp_file" - use bazel_version_file instead

• pkg_npm no longer has replace_with_version attribute, use substitutions instead

• concatjs: users need to change their load statements for ts_devserver
• Users will need to rename build_bazel_rules_typescript to npm_bazel_typescript and build_bazel_rules_karma to npm_bazel_karma in their projects
• If you use the internal API of tsc_wrapped you need to update the CompilerHost constructor calls.