Fix and re-enable tests for legacy Webpack-built JS

[kdmccormick]

Background

We have 8 legacy Javascript unit test suites in edx-platform: 7 run by Karma, and 1 run by Jest. Each of the 7 run by Karma uses a different config file. The best way to understand them is probably to look at this package.json snippet, which will merge in part of #35159.

{
  "...": "...",
  "scripts": {
    "...": "...",
    "test": "npm run test-cms && npm run test-lms && npm run test-xmodule && npm run test-common && npm run test-jest",
    "test-kind-vanilla": "npm run test-cms-vanilla && npm run test-xmodule-vanilla && npm run test-common-vanilla",
    "test-kind-require": "npm run test-cms-require && npm run test-common-require",
    "test-kind-webpack": "npm run test-cms-webpack && npm run test-lms-webpack && npm run test-xmodule-webpack",
    "test-cms": "npm run test-cms-vanilla && npm run test-cms-require && npm run test-cms-webpack",
    "test-cms-vanilla": "npm run test-suite -- cms/static/karma_cms.conf.js",
    "test-cms-require": "npm run test-suite -- cms/static/karma_cms_squire.conf.js",
    "test-cms-webpack": "npm run test-suite -- cms/static/karma_cms_webpack.conf.js",
    "test-lms": "npm run test-lms-webpack",
    "test-lms-webpack": "npm run test-suite -- lms/static/karma_lms.conf.js",
    "test-xmodule": "npm run test-xmodule-vanilla && npm run test-xmodule-webpack",
    "test-xmodule-vanilla": "npm run test-suite -- xmodule/js/karma_xmodule.conf.js",
    "test-xmodule-webpack": "npm run test-suite -- xmodule/js/karma_xmodule_webpack.conf.js",
    "test-common": "npm run test-common-vanilla && npm run test-common-require",
    "test-common-vanilla": "npm run test-suite -- common/static/karma_common.conf.js",
    "test-common-require": "npm run test-suite -- common/static/karma_common_requirejs.conf.js",
    "test-suite": "${NODE_WRAPPER:-xvfb-run --auto-servernum} node --max_old_space_size=4096 node_modules/.bin/karma start --single-run=true --capture-timeout=60000 --browsers=FirefoxNoUpdates",
    "test-jest": "jest"
  }
  "...": "..."
}

Essentially, there are three "kinds" of Karma test suites: three that test "vanilla" javascript, two that test RequireJS-based javascript, and three that test Webpack-based javascript. The Webpack-based ones have been quietly failing to build for an indeterminate amount of time, as explained here: #35955

We have since updated our Webpack config so that build failures under Karma would correctly signal the CI check to fail, but in order to do so, we've had to temporarily disable the three Webpack-based test suites.

UPDATE OCTOBER 2025: WIth #36595 merged, the test-xmodule-webpack suite is now fixed, but the test-lms-webpack and test-cms-webpack tests are still broken.

Tasks

• Re-enable the three Webpack-based test suites
  • test-xmodule-webpack
  • test-lms-webpack
  • test-cms-webpack
• Fix the Webpack build for these suites
• Fix or delete any unit tests that have regressed since the last time they were run in CI
  • Fix or delete? --> This is all deprecated code, so we do not want to spend too much time investing in its testing. If it is not obvious how to fix the unit test, then consider removing it.

[kdmccormick]

@ttqureshi The particular command we'd like to get working in order to test #36595 would be npm run test-xmodule-webpack.

Right now, this is the error that command gives me:

app@2b845988843f:~/edx-platform$ npm run test-xmodule-webpack

> edx@0.1.0 test-xmodule-webpack
> npm run test-karma-conf -- xmodule/js/karma_xmodule_webpack.conf.js


> edx@0.1.0 test-karma-conf
> node --max_old_space_size=4096 node_modules/.bin/karma start --single-run=true --capture-timeout=60000 --browsers=FirefoxNoUpdates xmodule/js/karma_xmodule_webpack.conf.js

webpack was not included as a framework in karma configuration, setting this automatically...

karma-webpack does not currently support custom entries, if this is something you need,
consider opening an issue.
ignoring attempt to set the entry option...

Webpack bundling...
10% building 0/1 entries 0/0 dependencies 0/0 modules(node:250) [DEP_WEBPACK_RULE_LOADER_OPTIONS_STRING] DeprecationWarning: Using a string as loader options is deprecated (ruleSet[1].rules[7].use[0].options)
(Use `node --trace-deprecation ...` to show where the warning was created)
10% building 0/1 entries 134/154 dependencies 40/60 modules[BABEL] Note: The code generator has deoptimised the styling of /openedx/edx-platform/common/static/common/js/vendor/hls.js as it exceeds the max of 500KB.
10% building 0/1 entries 147/163 dependencies 45/66 modules[BABEL] Note: The code generator has deoptimised the styling of /openedx/edx-platform/common/static/common/js/vendor/sinon.js as it exceeds the max of 500KB.
10% building 0/1 entries 150/192 dependencies 48/66 modules[BABEL] Note: The code generator has deoptimised the styling of /openedx/edx-platform/common/static/js/vendor/tinymce/js/tinymce/tinymce.full.min.js as it exceeds the max of 500KB.
Error: ENOENT: no such file or directory, open '/openedx/edx-platform/common/static/bundles/karma_runner_webpack.3615002655.js'
    at Object.openSync (node:fs:596:3)
    at Object.readFileSync (node:fs:464:35)
    at /openedx/edx-platform/node_modules/karma-webpack/lib/webpack/plugin.js:22:66
    at Array.forEach (<anonymous>)
    at /openedx/edx-platform/node_modules/karma-webpack/lib/webpack/plugin.js:17:29
    at Hook.eval [as callAsync] (eval at create (/openedx/edx-platform/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:38:1)
    at Hook.CALL_ASYNC_DELEGATE [as _callAsync] (/openedx/edx-platform/node_modules/tapable/lib/Hook.js:18:14)
    at onCompiled (/openedx/edx-platform/node_modules/webpack/lib/Compiler.js:518:21)
    at /openedx/edx-platform/node_modules/webpack/lib/Compiler.js:1347:17
    at eval (eval at create (/openedx/edx-platform/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:13:1)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
  errno: -2,
  syscall: 'open',
  code: 'ENOENT',
  path: '/openedx/edx-platform/common/static/bundles/karma_runner_webpack.3615002655.js'
}

[ttqureshi]

@kdmccormick I spent some time figuring out what's breaking. But I am not able to determine the exact root cause of the failure, but it appears to be related to build process. My suspicion is that some files are not being properly written to the common/static/bundles/ directory during compilation. This is likely why the expected karma_runner_webpack.<hash>.js file is missing.

[feanil]

FYI, a dependency on the ancient selenium-karma-webdriver-launcher will removed as a part of #36589

Whenever we come back to this, we will need to replace the relevant functionality with something more modern. But given that we were using this to pin the browser version and we probably don't want to do that, it's probably fine to just run the test with the latest version of firefox instead.