| // The path to the JS bundle is passed by the karma_test rule as the last command-line argument to |
| // the Karma binary. |
| const jsTestFile = process.argv[process.argv.length - 1]; |
| |
| // Detect whether we're running as a test (e.g. "bazel test //path/to/my:karma_test"). |
| // |
| // https://github.com/bazelbuild/rules_nodejs/blob/681c6683dac742f1e375a401c0399ec7783ac8fd/packages/karma/karma_web_test.bzl#L257 |
| const isBazelTest = !process.env.BUILD_WORKSPACE_DIRECTORY; // Set when running via "bazel run". |
| |
| module.exports = function (config) { |
| config.set({ |
| plugins: [ |
| 'karma-chrome-launcher', |
| 'karma-sinon', |
| 'karma-mocha', |
| 'karma-chai', |
| 'karma-chai-dom', |
| 'karma-spec-reporter', |
| ], |
| |
| // Frameworks are loaded in reverse order, so chai-dom loads after chai. |
| frameworks: ['mocha', 'chai-dom', 'chai', 'sinon'], |
| |
| files: [{ |
| pattern: jsTestFile, |
| // Force the test files to be served from disk on each request. Without this, interactive mode |
| // with ibazel does not work (e.g. "ibazel run //path/to/my:karma_test"). |
| nocache: true, |
| }], |
| |
| // Only use a headless browser when running as a test (i.e. "bazel test"). |
| // |
| // Do not launch any browsers when running interactively (i.e. with "bazel run"). The developer |
| // can open the printed out URL for the Karma server in their browser of choice. |
| browsers: isBazelTest ? ['ChromeHeadlessCustom'] : [], |
| |
| // Headless Chrome that works on the RBE toolchain container, and any other Docker container. |
| // |
| // https://github.com/puppeteer/puppeteer/blob/master/docs/troubleshooting.md#running-puppeteer-in-docker |
| customLaunchers: { |
| ChromeHeadlessCustom: { |
| base: 'ChromeHeadless', |
| flags: ['--no-sandbox', '--disable-dev-shm-usage', '--disable-gpu'], |
| }, |
| }, |
| |
| // Report the outcome of each individual test case to stdout. |
| // |
| // This is consistent with the output format of Puppeteer tests (and any other Node.js tests |
| // using Mocha). |
| colors: true, |
| reporters: ['spec'], |
| |
| // Run tests only once when invoked via "bazel test", otherwise Karma will run forever and Bazel |
| // will eventually time out and report test failure. |
| singleRun: isBazelTest, |
| |
| // Autowatch is disabled because it is currently broken in two major ways: |
| // |
| // 1. It doesn't force a browser refresh when files change. |
| // 2. Sometimes it randomly reports changed files as deleted, and stops executing the contents |
| // of those files for the remainder of the session. |
| // |
| // ibazel can be used to achieve a similar workflow: |
| // |
| // - `ibazel test //path/to/my:karma_test`: Reruns the tests on a headless Chrome every time |
| // the tests change, and reports the results on the console. |
| // - `ibazel run //path/to/my:karma_test`: Interactive mode. Prints out a URL that can be |
| // opened in the browser. Tests are rebuilt automatically when the code changes. Reload the |
| // page manually to see the changes. |
| autoWatch: false, |
| }); |
| }; |