@bazel/karma

Karma rules for Bazel

The Karma rules run karma tests with Bazel.

Installation

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

Now add this to your WORKSPACE to install the Karma dependencies:

# Fetch transitive Bazel dependencies of @bazel/karma
load("@npm//@bazel/karma:package.bzl", "npm_bazel_karma_dependencies")
npm_bazel_karma_dependencies()

This installs the io_bazel_rules_webtesting repository, if you haven't installed it earlier.

Finally, configure the rules_webtesting:

# Set up web testing, choose browsers we can test on
load("@io_bazel_rules_webtesting//web:repositories.bzl", "web_test_repositories")

web_test_repositories()

load("@io_bazel_rules_webtesting//web/versioned:browsers-0.3.2.bzl", "browser_repositories")

browser_repositories(
    chromium = True,
    firefox = True,
)

Installing with self-managed dependencies

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

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

karma_web_test

Runs unit tests in a browser with Karma.

When executed under bazel test, this uses a headless browser for speed. This is also because bazel test allows multiple targets to be tested together, and we don't want to open a Chrome window on your machine for each one. Also, under bazel test the test will execute and immediately terminate.

Running under ibazel test gives you a "watch mode" for your tests. The rule is optimized for this case - the test runner server will stay running and just re-serve the up-to-date JavaScript source bundle.

To debug a single test target, run it with bazel run instead. This will open a browser window on your computer. Also you can use any other browser by opening the URL printed when the test starts up. The test will remain running until you cancel the bazel run command.

This rule will use your system Chrome by default. In the default case, your environment must specify CHROME_BIN so that the rule will know which Chrome binary to run. Other browsers and customLaunchers may be set using the a base Karma configuration specified in the config_file attribute.

karma_web_test(srcs, deps, data, configuration_env_vars, bootstrap, runtime_deps, static_files,
               config_file, tags, peer_deps, kwargs)

PARAMETERS

Name	Description	Default
srcs	A list of JavaScript test files	[]
deps	Other targets which produce JavaScript such as `ts_library`	[]
data	Runtime dependencies	[]
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.	[]
bootstrap	JavaScript files to include *before* the module loader (require.js). For example, you can include Reflect,js for TypeScript decorator metadata reflection, or UMD bundles for third-party libraries.	[]
runtime_deps	Dependencies which should be loaded after the module loader but before the srcs and deps. These should be a list of targets which produce JavaScript such as `ts_library`. The files will be loaded in the same order they are declared by that rule.	[]
static_files	Arbitrary files which are available to be served on request. Files are served at: `/base/<WORKSPACE_NAME>/<path-to-file>`, e.g. `/base/npm_bazel_typescript/examples/testing/static_script.js`	[]
config_file	User supplied Karma configuration file. Bazel will override certain attributes of this configuration file. Attributes that are overridden will be outputted to the test log.	None
tags	Standard Bazel tags, this macro adds tags for ibazel support	[]
peer_deps	list of peer npm deps required by karma_web_test	["@npm//jasmine-core", "@npm//karma", "@npm//karma-chrome-launcher", "@npm//karma-firefox-launcher", "@npm//karma-jasmine", "@npm//karma-requirejs", "@npm//karma-sourcemap-loader", "@npm//requirejs", "@npm//tmp"]
kwargs	Passed through to `karma_web_test`	</td> </tr> </tbody>

karma_web_test_suite

Defines a test_suite of web_test targets that wrap a karma_web_test target.

This macro accepts all parameters in karma_web_test and adds additional parameters for the suite. See karma_web_test docs for all karma_web_test.

The wrapping macro is web_test_suite which comes from rules_websting: https://github.com/bazelbuild/rules_webtesting/blob/master/web/web.bzl.

karma_web_test_suite(name, browsers, web_test_data, wrapped_test_tags, kwargs)

PARAMETERS

Name	Description	Default
name	The base name of the test	</td> </tr> <tr id="karma_web_test_suite-browsers"> <td>browsers</td> <td> A sequence of labels specifying the browsers to use. </td> <td> None </td> </tr> <tr id="karma_web_test_suite-web_test_data"> <td>web_test_data</td> <td> Data dependencies for the wrapper web_test targets. </td> <td> [] </td> </tr> <tr id="karma_web_test_suite-wrapped_test_tags"> <td>wrapped_test_tags</td> <td> A list of test tag strings to use for the wrapped karma_web_test target.	["manual", "noci"]
kwargs	Arguments for the wrapped karma_web_test target.	</td> </tr> </tbody>