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
USAGE
karma_web_test(srcs, deps, data, configuration_env_vars, bootstrap, runtime_deps, static_files, config_file, tags, peer_deps, kwargs)
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.
By default we open a headless Chrome. To use a real Chrome browser window, you can pass
--define DISPLAY=true
to Bazel, along with configuration_env_vars = ["DISPLAY"]
on
karma_web_test
.
PARAMETERS
srcs
A list of JavaScript test files
Defaults to []
deps
Other targets which produce JavaScript such as ts_library
Defaults to []
data
Runtime dependencies
Defaults to []
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.
Defaults to []
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.
Defaults to []
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.
Defaults to []
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
Defaults to []
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.
Defaults to None
tags
Standard Bazel tags, this macro adds tags for ibazel support
Defaults to []
peer_deps
list of peer npm deps required by karma_web_test
Defaults to ["@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"]
kwargs
Passed through to karma_web_test
karma_web_test_suite
USAGE
karma_web_test_suite(name, browsers, web_test_data, wrapped_test_tags, kwargs)
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.
PARAMETERS
name
The base name of the test
browsers
A sequence of labels specifying the browsers to use.
Defaults to None
web_test_data
Data dependencies for the wrapper web_test targets.
Defaults to []
wrapped_test_tags
A list of test tag strings to use for the wrapped karma_web_test target.
Defaults to ["manual", "noci"]
kwargs
Arguments for the wrapped karma_web_test target.