/**

* Mocha's Karma config.

*

* IMPORTANT:

* - Karma must _always_ be run with `NODE_PATH=.` where `.` is the project

* root; this allows `karma-mocha` to use our built version of Mocha

* - You must build Mocha's browser bundle before running Karma. This is

* typically done automatically in `package-scripts.js`.

*

* There are actually several different configurations here depending on the

* values of various environment variables (e.g., `MOCHA_TEST`, `CI`, etc.),

* which is why it's so hairy.

*

* This code avoids mutating the configuration object (the `cfg` variable)

* directly; instead, we create new objects/arrays. This makes it a little more

* obvious what's happening, even though it's verbose.

*

* The main export is a function which Karma calls with a config object; the

* final line of this function should be `config.set(cfg)` which registers the

* configuration we've built.

*/

"use strict";

const fs = require("node:fs");

const path = require("node:path");

const os = require("node:os");

const rollupPlugin = require("./scripts/karma-rollup-plugin");

const BASE_BUNDLE_DIR_PATH = path.join(__dirname, ".karma");

const env = process.env;

const hostname = os.hostname();

const BROWSER = env.BROWSER;

/**

* @type KarmaConfig

*/

const baseConfig = {

frameworks: ["rollup", "mocha"],

files: [

// we use the BDD interface for all of the tests that

// aren't interface-specific.

"test/unit/*.spec.js",

],

plugins: [

"karma-mocha",

"karma-mocha-reporter",

"karma-chrome-launcher",

rollupPlugin,

],

rollup: {

configFile: "rollup.config.mjs",

include: ["test/**"],

},

reporters: ["mocha"],

colors: true,

browsers: ["ChromeHeadless"],

client: {

mocha: {

// this helps debug

reporter: "html",

},

},

mochaReporter: {

showDiff: true,

},

customLaunchers: {

ChromeDebug: {

base: "Chrome",

flags: ["--remote-debugging-port=9333"],

},

},

};

/**

*

* @param {KarmaConfig} config

*/

module.exports = (config) => {

let bundleDirPath = path.join(BASE_BUNDLE_DIR_PATH, hostname);

let cfg = { ...baseConfig };

// configuration for CI mode

if (env.CI) {

console.error("CI mode enabled");

if (env.GITHUB_RUN_ID) {

console.error("Github Actions detected");

const buildId = `github-${env.GITHUB_RUN_ID}_${env.GITHUB_RUN_NUMBER}`;

bundleDirPath = path.join(BASE_BUNDLE_DIR_PATH, buildId);

} else {

console.error(`Local environment (${hostname}) detected`);

console.error(`CI + local environment is not supported`);

console.error(`https://github.com/mochajs/mocha/issues/5616`);

}

}

cfg = createBundleDir(cfg, bundleDirPath);

cfg = chooseTestSuite(cfg, env.MOCHA_TEST);

// include sourcemap

cfg = {

...cfg,

files: [...cfg.files, { pattern: "./mocha.js.map", included: false }],

};

if (BROWSER) {

cfg = {

...cfg,

browsers: [BROWSER],

};

}

config.set(cfg);

};

/**

* Creates dir `bundleDirPath` if it does not exist; returns new Karma config

* containing `bundleDirPath` for rollup plugin.

*

* If this fails, the rollup plugin will use a temp dir.

* @param {KarmaConfig} cfg

* @param {string} [bundleDirPath] Path where the output bundle should live

* @returns {KarmaConfig} New Karma config

*/

const createBundleDir = (cfg, bundleDirPath) => {

if (bundleDirPath) {

try {

fs.mkdirSync(bundleDirPath, { recursive: true });

cfg = {

...cfg,

rollup: {

...cfg.rollup,

bundleDirPath,

},

};

} catch {

console.error(

`Failed to create ${bundleDirPath}; using temp directory instead`,

);

}

}

return { ...cfg };

};

/**

* Returns a new Karma config containing standard dependencies for our tests.

*

* Most suites use this.

* @param {KarmaConfig} cfg

* @returns {KarmaConfig} New Karma config

*/

const addStandardDependencies = (cfg) => ({

...cfg,

files: [

require.resolve("sinon/pkg/sinon.js"),

require.resolve("unexpected/unexpected"),

{

pattern: require.resolve("unexpected/unexpected.js.map"),

included: false,

},

require.resolve("unexpected-sinon"),

require.resolve("unexpected-eventemitter/dist/unexpected-eventemitter.js"),

require.resolve("./test/browser-specific/setup"),

...cfg.files,

],

rollup: {

...cfg.rollup,

external: [

"sinon",

"unexpected",

"unexpected-eventemitter",

"unexpected-sinon",

],

globals: {

sinon: "sinon",

unexpected: "weknowhow.expect",

"unexpected-sinon": "weknowhow.unexpectedSinon",

"unexpected-eventemitter": "unexpectedEventEmitter",

},

},

});

/**

* Returns a new Karma config to run with specific configuration (which cannot

* be run with other configurations) as specified by `value`. Known values:

*

* - `bdd` - `bdd`-specific tests

* - `tdd` - `tdd`-specific tests

* - `qunit` - `qunit`-specific tests

* - `esm` - ESM-specific tests

*

* Since we can't change Mocha's interface on-the-fly, tests for specific interfaces

* must be run in isolation.

* @param {KarmaConfig} cfg

* @param {string} [value] Configuration identifier, if any

* @returns {KarmaConfig} New Karma config

*/

const chooseTestSuite = (cfg, value) => {

switch (value) {

case "bdd":

case "tdd":

case "qunit":

return addStandardDependencies({

...cfg,

files: [`test/interfaces/${value}.spec.js`],

client: {

...cfg.client,

mocha: {

...cfg.client.mocha,

ui: value,

},

},

});

case "esm":

return addStandardDependencies({

...cfg,

files: [

{

pattern: "test/browser-specific/fixtures/esm.fixture.mjs",

type: "module",

},

{

pattern: "test/browser-specific/esm.spec.mjs",

type: "module",

},

],

});

default:

return addStandardDependencies({ ...cfg });

}

};

/**

* @typedef {object} KarmaConfig

* @property {string[]} files

*/