Built-in rules

These rules are available without any npm installation, via the WORKSPACE install of the build_bazel_rules_nodejs workspace.

This is necessary to bootstrap Bazel to run the package manager to download other rules from NPM.

Rules

node_repositories

To be run in user's WORKSPACE to install rules_nodejs dependencies.

This rule sets up node, npm, and yarn. The versions of these tools can be specified in one of three ways

Simplest Usage

Specify no explicit versions. This will download and use the latest NodeJS & Yarn that were available when the version of rules_nodejs you're using was released. Note that you can skip calling node_repositories in your WORKSPACE file - if you later try to yarn_install or npm_install, we'll automatically select this simple usage for you.

Forced version(s)

You can select the version of NodeJS and/or Yarn to download & use by specifying it when you call node_repositories, using a value that matches a known version (see the default values)

Using a custom version

You can pass in a custom list of NodeJS and/or Yarn repositories and URLs for node_resositories to use.

Custom NodeJS versions

To specify custom NodeJS versions, use the node_repositories attribute

node_repositories(
    node_repositories = {
        "10.10.0-darwin_amd64": ("node-v10.10.0-darwin-x64.tar.gz", "node-v10.10.0-darwin-x64", "00b7a8426e076e9bf9d12ba2d571312e833fe962c70afafd10ad3682fdeeaa5e"),
        "10.10.0-linux_amd64": ("node-v10.10.0-linux-x64.tar.xz", "node-v10.10.0-linux-x64", "686d2c7b7698097e67bcd68edc3d6b5d28d81f62436c7cf9e7779d134ec262a9"),
        "10.10.0-windows_amd64": ("node-v10.10.0-win-x64.zip", "node-v10.10.0-win-x64", "70c46e6451798be9d052b700ce5dadccb75cf917f6bf0d6ed54344c856830cfb"),
    },
)

These can be mapped to a custom download URL, using node_urls

node_repositories(
    node_version = "10.10.0",
    node_repositories = {"10.10.0-darwin_amd64": ("node-v10.10.0-darwin-x64.tar.gz", "node-v10.10.0-darwin-x64", "00b7a8426e076e9bf9d12ba2d571312e833fe962c70afafd10ad3682fdeeaa5e")},
    node_urls = ["https://mycorpproxy/mirror/node/v{version}/{filename}"],
)

A Mac client will try to download node from https://mycorpproxy/mirror/node/v10.10.0/node-v10.10.0-darwin-x64.tar.gz and expect that file to have sha256sum 00b7a8426e076e9bf9d12ba2d571312e833fe962c70afafd10ad3682fdeeaa5e

Custom Yarn versions

To specify custom Yarn versions, use the yarn_repositories attribute

node_repositories(
    yarn_repositories = {
        "1.12.1": ("yarn-v1.12.1.tar.gz", "yarn-v1.12.1", "09bea8f4ec41e9079fa03093d3b2db7ac5c5331852236d63815f8df42b3ba88d"),
    },
)

Like node_urls, the yarn_urls attribute can be used to provide a list of custom URLs to use to download yarn

node_repositories(
    yarn_repositories = {
        "1.12.1": ("yarn-v1.12.1.tar.gz", "yarn-v1.12.1", "09bea8f4ec41e9079fa03093d3b2db7ac5c5331852236d63815f8df42b3ba88d"),
    },
    yarn_version = "1.12.1",
    yarn_urls = [
        "https://github.com/yarnpkg/yarn/releases/download/v{version}/{filename}",
    ],
)

Will download yarn from https://github.com/yarnpkg/yarn/releases/download/v1.2.1/yarn-v1.12.1.tar.gz and expect the file to have sha256sum 09bea8f4ec41e9079fa03093d3b2db7ac5c5331852236d63815f8df42b3ba88d.

If you don't use Yarn at all, you can skip downloading it by setting yarn_urls = [].

Using a local version

To avoid downloads, you can check in vendored copies of NodeJS and/or Yarn and set vendored_node and or vendored_yarn to point to those before calling node_repositories. You can also point to a location where node is installed on your computer, but we don't recommend this because it leads to version skew between you, your coworkers, and your Continuous Integration environment. It also ties your build to a single platform, preventing you from cross-compiling into a Linux docker image on Mac for example.

See the the repositories documentation for how to use the resulting repositories.

Manual install

You can optionally pass a package_json array to node_repositories. This lets you use Bazel's version of yarn or npm, yet always run the package manager yourself. This is an advanced scenario you can use in place of the npm_install or yarn_install rules, but we don't recommend it, and might remove it in the future.

load("@build_bazel_rules_nodejs//:index.bzl", "node_repositories")
node_repositories(package_json = ["//:package.json", "//subpkg:package.json"])

Running bazel run @nodejs//:yarn_node_repositories in this repo would create /node_modules and /subpkg/node_modules.

Note that the dependency installation scripts will run in each subpackage indicated by the package_json attribute.

name

A unique name for this repository.

node_download_auth

auth to use for all url requests Example: {"type": "basic", "login": "", "password": "" }

node_repositories

Custom list of node repositories to use

A dictionary mapping NodeJS versions to sets of hosts and their corresponding (filename, strip_prefix, sha256) tuples. You should list a node binary for every platform users have, likely Mac, Windows, and Linux.

By default, if this attribute has no items, we'll use a list of all public NodeJS releases.

node_urls

custom list of URLs to use to download NodeJS

Each entry is a template for downloading a node distribution.

The {version} parameter is substituted with the node_version attribute, and {filename} with the matching entry from the node_repositories attribute.

node_version

the specific version of NodeJS to install or, if vendored_node is specified, the vendored version of node

package_json

(ADVANCED, not recommended) a list of labels, which indicate the package.json files that will be installed when you manually run the package manager, e.g. with bazel run @nodejs//:yarn_node_repositories or bazel run @nodejs//:npm_node_repositories install. If you use bazel-managed dependencies, you should omit this attribute.

Turn on --node_options=--preserve-symlinks for nodejs_binary and nodejs_test rules.

When this option is turned on, node will preserve the symlinked path for resolves instead of the default behavior of resolving to the real path. This means that all required files must be in be included in your runfiles as it prevents the default behavior of potentially resolving outside of the runfiles. For example, all required files need to be included in your node_modules filegroup. This option is desirable as it gives a stronger guarantee of hermeticity which is required for remote execution.

repo_mapping

A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.

For example, an entry "@foo": "@bar" declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).

vendored_node

the local path to a pre-installed NodeJS runtime.

If set then also set node_version to the version that of node that is vendored.

vendored_yarn

the local path to a pre-installed yarn tool

yarn_download_auth

auth to use for all url requests Example: {"type": "basic", "login": "", "password": "" }

yarn_repositories

Custom list of yarn repositories to use.

Dictionary mapping Yarn versions to their corresponding (filename, strip_prefix, sha256) tuples.

By default, if this attribute has no items, we'll use a list of all public NodeJS releases.

yarn_urls

custom list of URLs to use to download Yarn

Each entry is a template, similar to the node_urls attribute, using yarn_version and yarn_repositories in the substitutions.

If this list is empty, we won't download yarn at all.

yarn_version

the specific version of Yarn to install

nodejs_binary

Runs some JavaScript code in NodeJS.

name

A unique name for this target.

chdir

Working directory to run the binary or test in, relative to the workspace. By default, Bazel always runs in the workspace root. Due to implementation details, this argument must be underneath this package directory.

To run in the directory containing the nodejs_binary / nodejs_test, use

chdir = package_name()

(or if you're in a macro, use native.package_name())

WARNING: this will affect other paths passed to the program, either as arguments or in configuration files, which are workspace-relative. You may need ../../ segments to re-relativize such paths to the new working directory.

configuration_env_vars

Pass these configuration environment variables to the resulting binary. Chooses a subset of the configuration environment variables (taken from ctx.var), which also includes anything specified via the --define flag. Note, this can lead to different outputs produced by this rule.

data

Runtime dependencies which may be loaded during execution.

default_env_vars

Default environment variables that are added to configuration_env_vars.

This is separate from the default of configuration_env_vars so that a user can set configuration_env_vars without losing the defaults that should be set in most cases.

The set of default environment variables is:

  • VERBOSE_LOGS: use by some rules & tools to turn on debug output in their logs
  • NODE_DEBUG: used by node.js itself to print more logs
  • RUNFILES_LIB_DEBUG: print diagnostic message from Bazel runfiles.bash helper

entry_point

The script which should be executed first, usually containing a main function.

If the entry JavaScript file belongs to the same package (as the BUILD file), you can simply reference it by its relative name to the package directory:

nodejs_binary(
    name = "my_binary",
    ...
    entry_point = ":file.js",
)

You can specify the entry point as a typescript file so long as you also include the ts_library target in data:

ts_library(
    name = "main",
    srcs = ["main.ts"],
)

nodejs_binary(
    name = "bin",
    data = [":main"]
    entry_point = ":main.ts",
)

The rule will use the corresponding .js output of the ts_library rule as the entry point.

If the entry point target is a rule, it should produce a single JavaScript entry file that will be passed to the nodejs_binary rule. For example:

filegroup(
    name = "entry_file",
    srcs = ["main.js"],
)

nodejs_binary(
    name = "my_binary",
    entry_point = ":entry_file",
)

The entry_point can also be a label in another workspace:

nodejs_binary(
    name = "history-server",
    entry_point = "@npm//:node_modules/history-server/modules/cli.js",
    data = ["@npm//history-server"],
)

env

Specifies additional environment variables to set when the target is executed, subject to location expansion.

Link the workspace root to the bin_dir to support absolute requires like 'my_wksp/path/to/file'. If source files need to be required then they can be copied to the bin_dir with copy_to_bin.

templated_args

Arguments which are passed to every execution of the program. To pass a node startup option, prepend it with --node_options=, e.g. --node_options=--preserve-symlinks.

Subject to 'Make variable' substitution. See https://docs.bazel.build/versions/master/be/make-variables.html.

  1. Subject to predefined source/output path variables substitutions.

The predefined variables execpath, execpaths, rootpath, rootpaths, location, and locations take label parameters (e.g. $(execpath //foo:bar)) and substitute the file paths denoted by that label.

See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_label_variables for more info.

NB: This $(location) substition returns the manifest file path which differs from the *_binary & *_test args and genrule bazel substitions. This will be fixed in a future major release. See docs string of expand_location_into_runfiles macro in internal/common/expand_into_runfiles.bzl for more info.

The recommended approach is to now use $(rootpath) where you previously used $(location).

To get from a $(rootpath) to the absolute path that $$(rlocation $(location)) returned you can either use $$(rlocation $(rootpath)) if you are in the templated_args of a nodejs_binary or nodejs_test:

BUILD.bazel:

nodejs_test(
    name = "my_test",
    data = [":bootstrap.js"],
    templated_args = ["--node_options=--require=$$(rlocation $(rootpath :bootstrap.js))"],
)

or if you're in the context of a .js script you can pass the $(rootpath) as an argument to the script and use the javascript runfiles helper to resolve to the absolute path:

BUILD.bazel:

nodejs_test(
    name = "my_test",
    data = [":some_file"],
    entry_point = ":my_test.js",
    templated_args = ["$(rootpath :some_file)"],
)

my_test.js

const runfiles = require(process.env['BAZEL_NODE_RUNFILES_HELPER']);
const args = process.argv.slice(2);
const some_file = runfiles.resolveWorkspaceRelative(args[0]);

NB: Bazel will error if it sees the single dollar sign $(rlocation path) in templated_args as it will try to expand $(rlocation) since we now expand predefined & custom "make" variables such as $(COMPILATION_MODE), $(BINDIR) & $(TARGET_CPU) using ctx.expand_make_variables. See https://docs.bazel.build/versions/master/be/make-variables.html.

To prevent expansion of $(rlocation) write it as $$(rlocation). Bazel understands $$ to be the string literal $ and the expansion results in $(rlocation) being passed as an arg instead of being expanded. $(rlocation) is then evaluated by the bash node launcher script and it calls the rlocation function in the runfiles.bash helper. For example, the templated arg $$(rlocation $(rootpath //:some_file)) is expanded by Bazel to $(rlocation ./some_file) which is then converted in bash to the absolute path of //:some_file in runfiles by the runfiles.bash helper before being passed as an argument to the program.

NB: nodejs_binary and nodejs_test will preserve the legacy behavior of $(rlocation) so users don't need to update to $$(rlocation). This may be changed in the future.

  1. Subject to predefined variables & custom variable substitutions.

Predefined "Make" variables such as $(COMPILATION_MODE) and $(TARGET_CPU) are expanded. See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_variables.

Custom variables are also expanded including variables set through the Bazel CLI with --define=SOME_VAR=SOME_VALUE. See https://docs.bazel.build/versions/master/be/make-variables.html#custom_variables.

Predefined genrule variables are not supported in this context.

nodejs_test

Identical to nodejs_binary, except this can be used with bazel test as well. When the binary returns zero exit code, the test passes; otherwise it fails.

nodejs_test is a convenient way to write a novel kind of test based on running your own test runner. For example, the ts-api-guardian library has a way to assert the public API of a TypeScript program, and uses nodejs_test here: https://github.com/angular/angular/blob/master/tools/ts-api-guardian/index.bzl

If you just want to run a standard test using a test runner from npm, use the generated *_test target created by npm_install/yarn_install, such as mocha_test. Some test runners like Karma and Jasmine have custom rules with added features, e.g. jasmine_node_test.

By default, Bazel runs tests with a working directory set to your workspace root. Use the chdir attribute to change the working directory before the program starts.

To debug a Node.js test, we recommend saving a group of flags together in a "config". Put this in your tools/bazel.rc so it's shared with your team:

# Enable debugging tests with --config=debug
test:debug --test_arg=--node_options=--inspect-brk --test_output=streamed --test_strategy=exclusive --test_timeout=9999 --nocache_test_results

Now you can add --config=debug to any bazel test command line. The runtime will pause before executing the program, allowing you to connect a remote debugger.

name

A unique name for this target.

chdir

Working directory to run the binary or test in, relative to the workspace. By default, Bazel always runs in the workspace root. Due to implementation details, this argument must be underneath this package directory.

To run in the directory containing the nodejs_binary / nodejs_test, use

chdir = package_name()

(or if you're in a macro, use native.package_name())

WARNING: this will affect other paths passed to the program, either as arguments or in configuration files, which are workspace-relative. You may need ../../ segments to re-relativize such paths to the new working directory.

configuration_env_vars

Pass these configuration environment variables to the resulting binary. Chooses a subset of the configuration environment variables (taken from ctx.var), which also includes anything specified via the --define flag. Note, this can lead to different outputs produced by this rule.

data

Runtime dependencies which may be loaded during execution.

default_env_vars

Default environment variables that are added to configuration_env_vars.

This is separate from the default of configuration_env_vars so that a user can set configuration_env_vars without losing the defaults that should be set in most cases.

The set of default environment variables is:

  • VERBOSE_LOGS: use by some rules & tools to turn on debug output in their logs
  • NODE_DEBUG: used by node.js itself to print more logs
  • RUNFILES_LIB_DEBUG: print diagnostic message from Bazel runfiles.bash helper

entry_point

The script which should be executed first, usually containing a main function.

If the entry JavaScript file belongs to the same package (as the BUILD file), you can simply reference it by its relative name to the package directory:

nodejs_binary(
    name = "my_binary",
    ...
    entry_point = ":file.js",
)

You can specify the entry point as a typescript file so long as you also include the ts_library target in data:

ts_library(
    name = "main",
    srcs = ["main.ts"],
)

nodejs_binary(
    name = "bin",
    data = [":main"]
    entry_point = ":main.ts",
)

The rule will use the corresponding .js output of the ts_library rule as the entry point.

If the entry point target is a rule, it should produce a single JavaScript entry file that will be passed to the nodejs_binary rule. For example:

filegroup(
    name = "entry_file",
    srcs = ["main.js"],
)

nodejs_binary(
    name = "my_binary",
    entry_point = ":entry_file",
)

The entry_point can also be a label in another workspace:

nodejs_binary(
    name = "history-server",
    entry_point = "@npm//:node_modules/history-server/modules/cli.js",
    data = ["@npm//history-server"],
)

env

Specifies additional environment variables to set when the target is executed, subject to location expansion.

expected_exit_code

The expected exit code for the test. Defaults to 0.

Link the workspace root to the bin_dir to support absolute requires like 'my_wksp/path/to/file'. If source files need to be required then they can be copied to the bin_dir with copy_to_bin.

templated_args

Arguments which are passed to every execution of the program. To pass a node startup option, prepend it with --node_options=, e.g. --node_options=--preserve-symlinks.

Subject to 'Make variable' substitution. See https://docs.bazel.build/versions/master/be/make-variables.html.

  1. Subject to predefined source/output path variables substitutions.

The predefined variables execpath, execpaths, rootpath, rootpaths, location, and locations take label parameters (e.g. $(execpath //foo:bar)) and substitute the file paths denoted by that label.

See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_label_variables for more info.

NB: This $(location) substition returns the manifest file path which differs from the *_binary & *_test args and genrule bazel substitions. This will be fixed in a future major release. See docs string of expand_location_into_runfiles macro in internal/common/expand_into_runfiles.bzl for more info.

The recommended approach is to now use $(rootpath) where you previously used $(location).

To get from a $(rootpath) to the absolute path that $$(rlocation $(location)) returned you can either use $$(rlocation $(rootpath)) if you are in the templated_args of a nodejs_binary or nodejs_test:

BUILD.bazel:

nodejs_test(
    name = "my_test",
    data = [":bootstrap.js"],
    templated_args = ["--node_options=--require=$$(rlocation $(rootpath :bootstrap.js))"],
)

or if you're in the context of a .js script you can pass the $(rootpath) as an argument to the script and use the javascript runfiles helper to resolve to the absolute path:

BUILD.bazel:

nodejs_test(
    name = "my_test",
    data = [":some_file"],
    entry_point = ":my_test.js",
    templated_args = ["$(rootpath :some_file)"],
)

my_test.js

const runfiles = require(process.env['BAZEL_NODE_RUNFILES_HELPER']);
const args = process.argv.slice(2);
const some_file = runfiles.resolveWorkspaceRelative(args[0]);

NB: Bazel will error if it sees the single dollar sign $(rlocation path) in templated_args as it will try to expand $(rlocation) since we now expand predefined & custom "make" variables such as $(COMPILATION_MODE), $(BINDIR) & $(TARGET_CPU) using ctx.expand_make_variables. See https://docs.bazel.build/versions/master/be/make-variables.html.

To prevent expansion of $(rlocation) write it as $$(rlocation). Bazel understands $$ to be the string literal $ and the expansion results in $(rlocation) being passed as an arg instead of being expanded. $(rlocation) is then evaluated by the bash node launcher script and it calls the rlocation function in the runfiles.bash helper. For example, the templated arg $$(rlocation $(rootpath //:some_file)) is expanded by Bazel to $(rlocation ./some_file) which is then converted in bash to the absolute path of //:some_file in runfiles by the runfiles.bash helper before being passed as an argument to the program.

NB: nodejs_binary and nodejs_test will preserve the legacy behavior of $(rlocation) so users don't need to update to $$(rlocation). This may be changed in the future.

  1. Subject to predefined variables & custom variable substitutions.

Predefined "Make" variables such as $(COMPILATION_MODE) and $(TARGET_CPU) are expanded. See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_variables.

Custom variables are also expanded including variables set through the Bazel CLI with --define=SOME_VAR=SOME_VALUE. See https://docs.bazel.build/versions/master/be/make-variables.html#custom_variables.

Predefined genrule variables are not supported in this context.

npm_install

Runs npm install during workspace setup.

This rule will set the environment variable BAZEL_NPM_INSTALL to '1' (unless it set to another value in the environment attribute). Scripts may use to this to check if yarn is being run by the npm_install repository rule.

name

A unique name for this repository.

args

Arguments passed to npm install.

See npm CLI docs https://docs.npmjs.com/cli/install.html for complete list of supported arguments.

data

Data files required by this rule.

If symlink_node_modules is True, this attribute is optional since the package manager will run in your workspace folder. It is recommended, however, that all files that the package manager depends on, such as .rc files or files used in postinstall, are added symlink_node_modules is True so that the repository rule is rerun when any of these files change.

If symlink_node_modules is False, the package manager is run in the bazel external repository so all files that the package manager depends on must be listed.

environment

Environment variables to set before calling the package manager.

exports_directories_only

Export only top-level package directory artifacts from node_modules.

Turning this on will decrease the time it takes for Bazel to setup runfiles and sandboxing when there are a large number of npm dependencies as inputs to an action.

This breaks compatibility for labels that reference files within npm packages such as @npm//:node_modules/prettier/bin-prettier.js. To reference files within npm packages, you can use the directory_file_path rule and/or DirectoryFilePathInfo provider. Note, some rules still need upgrading to support consuming DirectoryFilePathInfo where needed.

NB: This feature requires runfiles be enabled due to an issue in Bazel which we are still investigating. On Windows runfiles are off by default and must be enabled with the --enable_runfiles flag when using this feature.

NB: ts_library does not support directory npm deps due to internal dependency on having all input sources files explicitly specified.

NB: protractor_web_test and protractor_web_test_suite do not support directory npm deps.

For the nodejs_binary & nodejs_test entry_point attribute (which often needs to reference a file within an npm package) you can set the entry_point to a dict with a single entry, where the key corresponds to the directory label and the value corresponds to the path within that directory to the entry point.

For example,

nodejs_binary(
    name = "prettier",
    data = ["@npm//prettier"],
    entry_point = "@npm//:node_modules/prettier/bin-prettier.js",
)

becomes,

nodejs_binary(
    name = "prettier",
    data = ["@npm//prettier"],
    entry_point = { "@npm//:node_modules/prettier": "bin-prettier.js" },
)

For labels that are passed to $(rootpath), $(execpath), or $(location) you can simply break these apart into the directory label that gets passed to the expander & path part to follows it.

For example,

$(rootpath @npm//:node_modules/prettier/bin-prettier.js")

becomes,

$(rootpath @npm//:node_modules/prettier)/bin-prettier.js

generate_local_modules_build_files

Enables the BUILD files auto generation for local modules installed with file: (npm) or link: (yarn)

When using a monorepo it's common to have modules that we want to use locally and publish to an external package repository. This can be achieved using a js_library rule with a package_name attribute defined inside the local package BUILD file. However, if the project relies on the local package dependency with file: (npm) or link: (yarn) to be used outside Bazel, this could introduce a race condition with both npm_install or yarn_install rules.

In order to overcome it, a link could be created to the package BUILD file from the npm external Bazel repository (so we can use a local BUILD file instead of an auto generated one), which require us to set generate_local_modules_build_files = False and complete a last step which is writing the expected targets on that same BUILD file to be later used both by npm_install or yarn_install rules, which are: <package_name__files>, <package_name__nested_node_modules>, <package_name__contents>, <package_name__typings> and the last one just <package_name>. If you doubt what those targets should look like, check the generated BUILD file for a given node module.

When true, the rule will follow the default behaviour of auto generating BUILD files for each node_module at install time.

When False, the rule will not auto generate BUILD files for node_modules that are installed as symlinks for local modules.

included_files

List of file extensions to be included in the npm package targets.

NB: This option has no effect when exports_directories_only is True as all files are automatically included in the exported directory for each npm package.

For example, [".js", ".d.ts", ".proto", ".json", ""].

This option is useful to limit the number of files that are inputs to actions that depend on npm package targets. See https://github.com/bazelbuild/bazel/issues/5153.

If set to an empty list then all files are included in the package targets. If set to a list of extensions, only files with matching extensions are included in the package targets. An empty string in the list is a special string that denotes that files with no extensions such as README should be included in the package targets.

This attribute applies to both the coarse @wksp//:node_modules target as well as the fine grained targets such as @wksp//foo.

Targets to link as npm packages.

A mapping of npm package names to bazel targets to linked into node_modules.

If package_path is also set, the bazel target will be linked to the node_modules at package_path along with other 3rd party npm packages from this rule.

For example,

yarn_install(
    name = "npm",
    package_json = "//web:package.json",
    yarn_lock = "//web:yarn.lock",
    package_path = "web",
    links = {
        "@scope/target": "//some/scoped/target",
        "target": "//some/target",
    },
)

creates targets in the @npm external workspace that can be used by other rules which are linked into web/node_modules along side the 3rd party deps since the project_path is web.

The above links will create the targets,

@npm//@scope/target
@npm//target

that can be referenced as data or deps by other rules such as nodejs_binary and ts_project and can be required as @scope/target and target with standard node_modules resolution at runtime,

nodejs_binary(
    name = "bin",
    entry_point = "bin.js",
    deps = [
        "@npm//@scope/target",
        "@npm//target"
        "@npm//other/dep"
    ],
)

ts_project(
    name = "test",
    srcs = [...],
    deps = [
        "@npm//@scope/target",
        "@npm//target"
        "@npm//other/dep"
    ],
)

manual_build_file_contents

Experimental attribute that can be used to override the generated BUILD.bazel file and set its contents manually.

Can be used to work-around a bazel performance issue if the default @wksp//:node_modules target has too many files in it. See https://github.com/bazelbuild/bazel/issues/5153. If you are running into performance issues due to a large node_modules target it is recommended to switch to using fine grained npm dependencies.

npm_command

The npm command to run, to install dependencies.

See npm docs https://docs.npmjs.com/cli/v6/commands

In particular, for "ci" it says:

If dependencies in the package lock do not match those in package.json, npm ci will exit with an error, instead of updating the package lock.

package_json

package_lock_json

package_path

If set, link the 3rd party node_modules dependencies under the package path specified.

In most cases, this should be the directory of the package.json file so that the linker links the node_modules in the same location they are found in the source tree. In a future release, this will default to the package.json directory. This is planned for 4.0: https://github.com/bazelbuild/rules_nodejs/issues/2451

patch_args

The arguments given to the patch tool. Defaults to -p0, however -p1 will usually be needed for patches generated by git. If multiple -p arguments are specified, the last one will take effect.If arguments other than -p are specified, Bazel will fall back to use patch command line tool instead of the Bazel-native patch implementation. When falling back to patch command line tool and patch_tool attribute is not specified, patch will be used.

patch_tool

The patch(1) utility to use. If this is specified, Bazel will use the specifed patch tool instead of the Bazel-native patch implementation.

post_install_patches

Patch files to apply after running package manager.

This can be used to make changes to installed packages after the package manager runs.

File paths in patches should be relative to workspace root.

pre_install_patches

Patch files to apply before running package manager.

This can be used to make changes to package.json or other data files passed in before running the package manager.

File paths in patches should be relative to workspace root.

quiet

If stdout and stderr should be printed to the terminal.

repo_mapping

A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.

For example, an entry "@foo": "@bar" declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).

strict_visibility

Turn on stricter visibility for generated BUILD.bazel files

When enabled, only dependencies within the given package.json file are given public visibility. All transitive dependencies are given limited visibility, enforcing that all direct dependencies are listed in the package.json file.

Turn symlinking of node_modules on

This requires the use of Bazel 0.26.0 and the experimental managed_directories feature.

When true, the package manager will run in the package.json folder and the resulting node_modules folder will be symlinked into the external repository create by this rule.

When false, the package manager will run in the external repository created by this rule and any files other than the package.json file and the lock file that are required for it to run should be listed in the data attribute.

timeout

Maximum duration of the package manager execution in seconds.

pkg_npm

The pkg_npm rule creates a directory containing a publishable npm artifact.

Example:

load("@build_bazel_rules_nodejs//:index.bzl", "pkg_npm")

pkg_npm(
    name = "my_package",
    srcs = ["package.json"],
    deps = [":my_typescript_lib"],
    substitutions = {"//internal/": "//"},
)

You can use a pair of // BEGIN-INTERNAL ... // END-INTERNAL comments to mark regions of files that should be elided during publishing. For example:

function doThing() {
    // BEGIN-INTERNAL
    // This is a secret internal-only comment
    doInternalOnlyThing();
    // END-INTERNAL
}

With the Bazel stamping feature, pkg_npm will replace any placeholder version in your package with the actual version control tag. See the stamping documentation

Usage:

pkg_npm yields four labels. Build the package directory using the default label:

$ bazel build :my_package
Target //:my_package up-to-date:
  bazel-out/fastbuild/bin/my_package
$ ls -R bazel-out/fastbuild/bin/my_package

Dry-run of publishing to npm, calling npm pack (it builds the package first if needed):

$ bazel run :my_package.pack
INFO: Running command line: bazel-out/fastbuild/bin/my_package.pack
my-package-name-1.2.3.tgz
$ tar -tzf my-package-name-1.2.3.tgz

Actually publish the package with npm publish (also builds first):

# Check login credentials
$ bazel run @nodejs//:npm_node_repositories who
# Publishes the package
$ bazel run :my_package.publish

You can pass arguments to npm by escaping them from Bazel using a double-hyphen, for example:

bazel run my_package.publish -- --tag=next

It is also possible to use the resulting tar file file from the .pack as an action input via the .tar label. To make use of this label, the tgz attribute must be set, and the generating pkg_npm rule must have a valid package.json file as part of its sources:

pkg_npm(
    name = "my_package",
    srcs = ["package.json"],
    deps = [":my_typescript_lib"],
    tgz = "my_package.tgz",
)

my_rule(
    name = "foo",
    srcs = [
        "//:my_package.tar",
    ],
)

name

A unique name for this target.

deps

Other targets which produce files that should be included in the package, such as rollup_bundle

nested_packages

Other pkg_npm rules whose content is copied into this package.

node_context_data

Provides info about the build context, such as stamping.

By default it reads from the bazel command line, such as the --stamp argument. Use this to override values for this target, such as enabling or disabling stamping. You can use the node_context_data rule in @build_bazel_rules_nodejs//internal/node:context.bzl to create a NodeContextInfo.

package_name

Optional package_name that this npm package may be imported as.

package_path

The directory in the workspace to link to. If set, link this pkg_npm to the node_modules under the package path specified. If unset, the default is to link to the node_modules root of the workspace.

srcs

Files inside this directory which are simply copied into the package.

substitutions

Key-value pairs which are replaced in all the files while building the package.

You can use values from the workspace status command using curly braces, for example {"0.0.0-PLACEHOLDER": "{STABLE_GIT_VERSION}"}.

See the section on stamping in the README

tgz

If set, will create a .tgz file that can be used as an input to another rule, the tar will be given the name assigned to this attribute.

NOTE: If this attribute is set, a valid package.json file must be included in the sources of this target

vendor_external

External workspaces whose contents should be vendored into this workspace. Avoids external/foo path segments in the resulting package.

pkg_web

Assembles a web application from source files.

name

A unique name for this target.

additional_root_paths

Path prefixes to strip off all srcs relative to the root of the repo, in addition to the current package. Longest wins.

node_context_data

Provides info about the build context, such as stamping.

By default it reads from the bazel command line, such as the --stamp argument. Use this to override values for this target, such as enabling or disabling stamping. You can use the node_context_data rule in @build_bazel_rules_nodejs//internal/node:context.bzl to create a NodeContextInfo.

srcs

Files which should be copied into the package

substitutions

Key-value pairs which are replaced in all the files while building the package.

You can use values from the workspace status command using curly braces, for example {"0.0.0-PLACEHOLDER": "{STABLE_GIT_VERSION}"}. See the section on stamping in the README.

yarn_install

Runs yarn install during workspace setup.

This rule will set the environment variable BAZEL_YARN_INSTALL to '1' (unless it set to another value in the environment attribute). Scripts may use to this to check if yarn is being run by the yarn_install repository rule.

name

A unique name for this repository.

args

Arguments passed to yarn install.

See yarn CLI docs https://yarnpkg.com/en/docs/cli/install for complete list of supported arguments.

data

Data files required by this rule.

If symlink_node_modules is True, this attribute is optional since the package manager will run in your workspace folder. It is recommended, however, that all files that the package manager depends on, such as .rc files or files used in postinstall, are added symlink_node_modules is True so that the repository rule is rerun when any of these files change.

If symlink_node_modules is False, the package manager is run in the bazel external repository so all files that the package manager depends on must be listed.

environment

Environment variables to set before calling the package manager.

exports_directories_only

Export only top-level package directory artifacts from node_modules.

Turning this on will decrease the time it takes for Bazel to setup runfiles and sandboxing when there are a large number of npm dependencies as inputs to an action.

This breaks compatibility for labels that reference files within npm packages such as @npm//:node_modules/prettier/bin-prettier.js. To reference files within npm packages, you can use the directory_file_path rule and/or DirectoryFilePathInfo provider. Note, some rules still need upgrading to support consuming DirectoryFilePathInfo where needed.

NB: This feature requires runfiles be enabled due to an issue in Bazel which we are still investigating. On Windows runfiles are off by default and must be enabled with the --enable_runfiles flag when using this feature.

NB: ts_library does not support directory npm deps due to internal dependency on having all input sources files explicitly specified.

NB: protractor_web_test and protractor_web_test_suite do not support directory npm deps.

For the nodejs_binary & nodejs_test entry_point attribute (which often needs to reference a file within an npm package) you can set the entry_point to a dict with a single entry, where the key corresponds to the directory label and the value corresponds to the path within that directory to the entry point.

For example,

nodejs_binary(
    name = "prettier",
    data = ["@npm//prettier"],
    entry_point = "@npm//:node_modules/prettier/bin-prettier.js",
)

becomes,

nodejs_binary(
    name = "prettier",
    data = ["@npm//prettier"],
    entry_point = { "@npm//:node_modules/prettier": "bin-prettier.js" },
)

For labels that are passed to $(rootpath), $(execpath), or $(location) you can simply break these apart into the directory label that gets passed to the expander & path part to follows it.

For example,

$(rootpath @npm//:node_modules/prettier/bin-prettier.js")

becomes,

$(rootpath @npm//:node_modules/prettier)/bin-prettier.js

frozen_lockfile

Use the --frozen-lockfile flag for yarn.

Don't generate a yarn.lock lockfile and fail if an update is needed.

This flag enables an exact install of the version that is specified in the yarn.lock file. This helps to have reproducible builds across builds.

To update a dependency or install a new one run the yarn install command with the vendored yarn binary. bazel run @nodejs//:yarn install. You can pass the options like bazel run @nodejs//:yarn install -- -D <dep-name>.

generate_local_modules_build_files

Enables the BUILD files auto generation for local modules installed with file: (npm) or link: (yarn)

When using a monorepo it's common to have modules that we want to use locally and publish to an external package repository. This can be achieved using a js_library rule with a package_name attribute defined inside the local package BUILD file. However, if the project relies on the local package dependency with file: (npm) or link: (yarn) to be used outside Bazel, this could introduce a race condition with both npm_install or yarn_install rules.

In order to overcome it, a link could be created to the package BUILD file from the npm external Bazel repository (so we can use a local BUILD file instead of an auto generated one), which require us to set generate_local_modules_build_files = False and complete a last step which is writing the expected targets on that same BUILD file to be later used both by npm_install or yarn_install rules, which are: <package_name__files>, <package_name__nested_node_modules>, <package_name__contents>, <package_name__typings> and the last one just <package_name>. If you doubt what those targets should look like, check the generated BUILD file for a given node module.

When true, the rule will follow the default behaviour of auto generating BUILD files for each node_module at install time.

When False, the rule will not auto generate BUILD files for node_modules that are installed as symlinks for local modules.

included_files

List of file extensions to be included in the npm package targets.

NB: This option has no effect when exports_directories_only is True as all files are automatically included in the exported directory for each npm package.

For example, [".js", ".d.ts", ".proto", ".json", ""].

This option is useful to limit the number of files that are inputs to actions that depend on npm package targets. See https://github.com/bazelbuild/bazel/issues/5153.

If set to an empty list then all files are included in the package targets. If set to a list of extensions, only files with matching extensions are included in the package targets. An empty string in the list is a special string that denotes that files with no extensions such as README should be included in the package targets.

This attribute applies to both the coarse @wksp//:node_modules target as well as the fine grained targets such as @wksp//foo.

Targets to link as npm packages.

A mapping of npm package names to bazel targets to linked into node_modules.

If package_path is also set, the bazel target will be linked to the node_modules at package_path along with other 3rd party npm packages from this rule.

For example,

yarn_install(
    name = "npm",
    package_json = "//web:package.json",
    yarn_lock = "//web:yarn.lock",
    package_path = "web",
    links = {
        "@scope/target": "//some/scoped/target",
        "target": "//some/target",
    },
)

creates targets in the @npm external workspace that can be used by other rules which are linked into web/node_modules along side the 3rd party deps since the project_path is web.

The above links will create the targets,

@npm//@scope/target
@npm//target

that can be referenced as data or deps by other rules such as nodejs_binary and ts_project and can be required as @scope/target and target with standard node_modules resolution at runtime,

nodejs_binary(
    name = "bin",
    entry_point = "bin.js",
    deps = [
        "@npm//@scope/target",
        "@npm//target"
        "@npm//other/dep"
    ],
)

ts_project(
    name = "test",
    srcs = [...],
    deps = [
        "@npm//@scope/target",
        "@npm//target"
        "@npm//other/dep"
    ],
)

manual_build_file_contents

Experimental attribute that can be used to override the generated BUILD.bazel file and set its contents manually.

Can be used to work-around a bazel performance issue if the default @wksp//:node_modules target has too many files in it. See https://github.com/bazelbuild/bazel/issues/5153. If you are running into performance issues due to a large node_modules target it is recommended to switch to using fine grained npm dependencies.

package_json

package_path

If set, link the 3rd party node_modules dependencies under the package path specified.

In most cases, this should be the directory of the package.json file so that the linker links the node_modules in the same location they are found in the source tree. In a future release, this will default to the package.json directory. This is planned for 4.0: https://github.com/bazelbuild/rules_nodejs/issues/2451

patch_args

The arguments given to the patch tool. Defaults to -p0, however -p1 will usually be needed for patches generated by git. If multiple -p arguments are specified, the last one will take effect.If arguments other than -p are specified, Bazel will fall back to use patch command line tool instead of the Bazel-native patch implementation. When falling back to patch command line tool and patch_tool attribute is not specified, patch will be used.

patch_tool

The patch(1) utility to use. If this is specified, Bazel will use the specifed patch tool instead of the Bazel-native patch implementation.

post_install_patches

Patch files to apply after running package manager.

This can be used to make changes to installed packages after the package manager runs.

File paths in patches should be relative to workspace root.

pre_install_patches

Patch files to apply before running package manager.

This can be used to make changes to package.json or other data files passed in before running the package manager.

File paths in patches should be relative to workspace root.

quiet

If stdout and stderr should be printed to the terminal.

repo_mapping

A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.

For example, an entry "@foo": "@bar" declares that, for any time this repository depends on @foo (such as a dependency on @foo//some:target, it should actually resolve that dependency within globally-declared @bar (@bar//some:target).

strict_visibility

Turn on stricter visibility for generated BUILD.bazel files

When enabled, only dependencies within the given package.json file are given public visibility. All transitive dependencies are given limited visibility, enforcing that all direct dependencies are listed in the package.json file.

Turn symlinking of node_modules on

This requires the use of Bazel 0.26.0 and the experimental managed_directories feature.

When true, the package manager will run in the package.json folder and the resulting node_modules folder will be symlinked into the external repository create by this rule.

When false, the package manager will run in the external repository created by this rule and any files other than the package.json file and the lock file that are required for it to run should be listed in the data attribute.

timeout

Maximum duration of the package manager execution in seconds.

use_global_yarn_cache

Use the global yarn cache on the system.

The cache lets you avoid downloading packages multiple times. However, it can introduce non-hermeticity, and the yarn cache can have bugs.

Disabling this attribute causes every run of yarn to have a unique cache_directory.

If True, this rule will pass --mutex network to yarn to ensure that the global cache can be shared by parallelized yarn_install rules.

If False, this rule will pass --cache-folder /path/to/external/repository/__yarn_cache to yarn so that the local cache is contained within the external repository.

yarn_lock

Macros and Functions

check_bazel_version

Verify the users Bazel version is at least the given one.

This can be used in rule implementations that depend on changes in Bazel, to warn users about a mismatch between the rule and their installed Bazel version.

This should not be used in users WORKSPACE files. To locally pin your Bazel version, just create the .bazelversion file in your workspace.

minimum_bazel_version

a string indicating the minimum version

message

optional string to print to your users, could be used to help them update

copy_to_bin

Copies a source file to bazel-bin at the same workspace-relative path.

e.g. <workspace_root>/foo/bar/a.txt -> <bazel-bin>/foo/bar/a.txt

This is useful to populate the output folder with all files needed at runtime, even those which aren't outputs of a Bazel rule.

This way you can run a binary in the output folder (execroot or runfiles_root) without that program needing to rely on a runfiles helper library or be aware that files are divided between the source tree and the output tree.

name

Name of the rule.

srcs

A List of Labels. File(s) to to copy.

kwargs

further keyword arguments, e.g. visibility

generated_file_test

Tests that a file generated by Bazel has identical content to a file in the workspace.

This is useful for testing, where a "snapshot" or "golden" file is checked in, so that you can code review changes to the generated output.

name

Name of the rule.

generated

a Label of the output file generated by another rule

src

Label of the source file in the workspace

When true, creates a test that will fail only if the golden file is not found anywhere within the generated file. Note that the .update rule is not generated in substring mode.

src_dbg

if the build uses --compilation_mode dbg then some rules will produce different output. In this case you can specify what the dbg version of the output should look like

visibility

visibility for both test target & update target

kwargs

extra arguments passed to the underlying nodejs_test

js_library

Groups JavaScript code so that it can be depended on like an npm package.

js_library is intended to be used internally within Bazel, such as between two libraries in your monorepo. This rule doesn't perform any build steps ("actions") so it is similar to a filegroup. However it provides several Bazel "Providers" for interop with other rules.

Compare this to pkg_npm which just produces a directory output, and therefore can't expose individual files to downstream targets and causes a cascading re-build of all transitive dependencies when any file changes. Also pkg_npm is intended to publish your code for external usage outside of Bazel, like by publishing to npm or artifactory, while js_library is for internal dependencies within your repo.

js_library also copies any source files into the bazel-out folder. This is the same behavior as the copy_to_bin rule. By copying the complete package to the output tree, we ensure that the linker (our npm link equivalent) will make your source files available in the node_modules tree where resolvers expect them. It also means you can have relative imports between the files rather than being forced to use Bazel's "Runfiles" semantics where any program might need a helper library to resolve files between the logical union of the source tree and the output tree.

Example

A typical example usage of js_library is to expose some sources with a package name:

ts_project(
    name = "compile_ts",
    srcs = glob(["*.ts"]),
)

js_library(
    name = "my_pkg",
    # Code that depends on this target can import from "@myco/mypkg"
    package_name = "@myco/mypkg",
    # Consumers might need fields like "main" or "typings"
    srcs = ["package.json"],
    # The .js and .d.ts outputs from above will be part of the package
    deps = [":compile_ts"],
)

To help work with "named AMD" modules as required by concatjs_devserver and other Google-style "concatjs" rules, js_library has some undocumented advanced features you can find in the source code or in our examples. These should not be considered a public API and aren't subject to our usual support and semver guarantees.

Outputs

Like all Bazel rules it produces a default output by providing DefaultInfo. You'll get these outputs if you include this in the srcs of a typical rule like filegroup, and these will be the printed result when you bazel build //some:js_library_target. The default outputs are all of:

  • DefaultInfo produced by targets in deps
  • A copy of all sources (InputArtifacts from your source tree) in the bazel-out directory

When there are TypeScript typings files, js_library provides DeclarationInfo so this target can be a dependency of a TypeScript rule. This includes any .d.ts files in srcs as well as transitive ones from deps. It will also provide OutputGroupInfo with a "types" field, so you can select the typings outputs with bazel build //some:js_library_target --output_groups=types or with a filegroup rule using the output_group attribute.

In order to work with the linker (similar to npm link for first-party monorepo deps), js_library provides LinkablePackageInfo for use with our "linker" that makes this package importable.

It also provides:

name

The name for the target

srcs

The list of files that comprise the package

package_name

The name it will be imported by. Should match the "name" field in the package.json file.

If package_name == "$node_modules$" this indictates that this js_library target is one or more external npm packages in node_modules. This is a special case that used be covered by the internal only external_npm_package attribute. NB: '$' is an illegal character for npm packages names so this reserved name will not conflict with any valid package_name values

This is used by the yarn_install & npm_install repository rules for npm dependencies installed by yarn & npm. When true, js_library will provide ExternalNpmPackageInfo.

It can also be used for user-managed npm dependencies if node_modules is layed out outside of bazel. For example,

js_library(
    name = "node_modules",
    srcs = glob(
        include = [
            "node_modules/**/*.js",
            "node_modules/**/*.d.ts",
            "node_modules/**/*.json",
            "node_modules/.bin/*",
        ],
        exclude = [
            # Files under test & docs may contain file names that
            # are not legal Bazel labels (e.g.,
            # node_modules/ecstatic/test/public/中文/檔案.html)
            "node_modules/**/test/**",
            "node_modules/**/docs/**",
            # Files with spaces in the name are not legal Bazel labels
            "node_modules/**/* */**",
            "node_modules/**/* *",
        ],
    ),
    # Special value to provide ExternalNpmPackageInfo which is used by downstream
    # rules that use these npm dependencies
    package_name = "$node_modules$",
)

See examples/user_managed_deps for a working example of user-managed npm dependencies.

package_path

The directory in the workspace to link to. If set, link this js_library to the node_modules under the package path specified. If unset, the default is to link to the node_modules root of the workspace.

deps

Other targets that provide JavaScript code

kwargs

Other attributes

npm_package_bin

Run an arbitrary npm package binary (e.g. a program under node_modules/.bin/*) under Bazel.

It must produce outputs. If you just want to run a program with bazel run, use the nodejs_binary rule.

This is like a genrule() except that it runs our launcher script that first links the node_modules tree before running the program.

By default, Bazel runs actions with a working directory set to your workspace root. Use the chdir attribute to change the working directory before the program runs.

This is a great candidate to wrap with a macro, as documented: https://docs.bazel.build/versions/master/skylark/macros.html#full-example

tool

a label for a binary to run, like @npm//terser/bin:terser. This is the longer form of package/package_bin. Note that you can also refer to a binary in your local workspace.

package

an npm package whose binary to run, like "terser". Assumes your node_modules are installed in a workspace called "npm"

package_bin

the "bin" entry from package that should be run. By default package_bin is the same string as package

data

similar to genrule.srcs may also include targets that produce or reference npm packages which are needed by the tool

env

specifies additional environment variables to set when the target is executed

outs

similar to genrule.outs

args

Command-line arguments to the tool.

Subject to 'Make variable' substitution. See https://docs.bazel.build/versions/master/be/make-variables.html.

  1. Predefined source/output path substitions is applied first:

See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_label_variables.

Use $(execpath) $(execpaths) to expand labels to the execroot (where Bazel runs build actions).

Use $(rootpath) $(rootpaths) to expand labels to the runfiles path that a built binary can use to find its dependencies.

Since npm_package_bin is used primarily for build actions, in most cases you'll want to use $(execpath) or $(execpaths) to expand locations.

Using $(location) and $(locations) expansions is not recommended as these are a synonyms for either $(execpath) or $(rootpath) depending on the context.

  1. "Make" variables are expanded second:

Predefined "Make" variables such as $(COMPILATION_MODE) and $(TARGET_CPU) are expanded. See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_variables.

Like genrule, you may also use some syntax sugar for locations.

  • $@: if you have only one output file, the location of the output
  • $(@D): The output directory. If output_dir=False and there is only one file name in outs, this expands to the directory containing that file. If there are multiple files, this instead expands to the package's root directory in the genfiles tree, even if all generated files belong to the same subdirectory! If output_dir=True then this corresponds to the output directory which is the $(RULEDIR)/{target_name}.
  • $(RULEDIR): the root output directory of the rule, corresponding with its package (can be used with output_dir=True or False)

See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_genrule_variables.

Custom variables are also expanded including variables set through the Bazel CLI with --define=SOME_VAR=SOME_VALUE. See https://docs.bazel.build/versions/master/be/make-variables.html#custom_variables.

stderr

set to capture the stderr of the binary to a file, which can later be used as an input to another target subject to the same semantics as outs

stdout

set to capture the stdout of the binary to a file, which can later be used as an input to another target subject to the same semantics as outs

exit_code_out

set to capture the exit code of the binary to a file, which can later be used as an input to another target subject to the same semantics as outs. Note that setting this will force the binary to exit 0. If the binary creates outputs and these are declared, they must still be created

output_dir

set to True if you want the output to be a directory Exactly one of outs, output_dir may be used. If you output a directory, there can only be one output, which will be a directory named the same as the target.

Link the workspace root to the bin_dir to support absolute requires like 'my_wksp/path/to/file'. If source files need to be required then they can be copied to the bin_dir with copy_to_bin.

chdir

Working directory to run the binary or test in, relative to the workspace.

By default, Bazel always runs in the workspace root.

To run in the directory containing the npm_package_bin under the source tree, use chdir = package_name() (or if you're in a macro, use native.package_name()).

To run in the output directory where the npm_package_bin writes outputs, use chdir = "$(RULEDIR)"

WARNING: this will affect other paths passed to the program, either as arguments or in configuration files, which are workspace-relative. You may need ../../ segments to re-relativize such paths to the new working directory. In a BUILD file you could do something like this to point to the output path:

_package_segments = len(package_name().split("/"))
npm_package_bin(
    ...
    chdir = package_name(),
    # ../.. segments to re-relative paths from the chdir back to workspace
    args = ["/".join([".."] * _package_segments + ["$@"])],
)

kwargs

additional undocumented keyword args

params_file

Generates a UTF-8 encoded params file from a list of arguments.

Handles variable substitutions for args.

name

Name of the rule.

out

Path of the output file, relative to this package.

args

Arguments to concatenate into a params file.

Subject to 'Make variable' substitution. See https://docs.bazel.build/versions/master/be/make-variables.html.

  1. Subject to predefined source/output path variables substitutions.

The predefined variables execpath, execpaths, rootpath, rootpaths, location, and locations take label parameters (e.g. $(execpath //foo:bar)) and substitute the file paths denoted by that label.

See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_label_variables for more info.

NB: This $(location) substition returns the manifest file path which differs from the *_binary & *_test args and genrule bazel substitions. This will be fixed in a future major release. See docs string of expand_location_into_runfiles macro in internal/common/expand_into_runfiles.bzl for more info.

  1. Subject to predefined variables & custom variable substitutions.

Predefined "Make" variables such as $(COMPILATION_MODE) and $(TARGET_CPU) are expanded. See https://docs.bazel.build/versions/master/be/make-variables.html#predefined_variables.

Custom variables are also expanded including variables set through the Bazel CLI with --define=SOME_VAR=SOME_VALUE. See https://docs.bazel.build/versions/master/be/make-variables.html#custom_variables.

Predefined genrule variables are not supported in this context.

data

Data for $(location) expansions in args.

newline

Line endings to use. One of ["auto", "unix", "windows"].

"auto" for platform-determined "unix" for LF "windows" for CRLF

kwargs