🔥 Remove Karma (configuration, dependencies and Karma-only test helpers)

[thomas-lebeau]

Motivation

Karma is deprecated (RUM-8075). With #5135 (unit) and #5136 (unit-bs), all unit tests run on Vitest, so the Karma setup is now unused. Stacked on #5136.

Changes

Removes what was only used by Karma:

• test/unit/karma.base.conf.js, test/unit/karma.bs.conf.js
• the Karma reporter plugins (jasmineSeedReporterPlugin.js, karmaDuplicateTestNameReporterPlugin.js, karmaSkippedFailedReporterPlugin.js, karmaUnexpectedErrorLogReporterPlugin.js) and the globalThis / Object.hasOwn polyfill files
• dependencies: karma, karma-browserstack-launcher, karma-jasmine, karma-junit-reporter, karma-sourcemap-loader, karma-spec-reporter, karma-webpack, plus swc-loader and @swc/core (added in ✨ [RUM-5500] React-router v7 support #3299 to transpile dependencies for Karma; nothing else uses them), and their LICENSE-3rdparty.csv entries
• the karma-webpack update pins in renovate.json and .github/dependabot.yml (RUM-3130)
• stale Karma mentions in AGENTS.md and comments

Kept: test/unit/browsers.conf.ts (BrowserStack browser matrix, used by the Vitest BrowserStack config), and jasmine-core / @types/jasmine / eslint-plugin-jasmine (used by the Jasmine compatibility shim until specs are migrated to the Vitest API).

Merges the test helpers that had a Karma version and a Vitest copy (selected through aliases in the Vitest config) into a single Vitest implementation, and drops the aliases:

• registerCleanupTask runs tasks with onTestFinished
• getCurrentJasmineSpec is tracked from forEach.ts (a setup file run for every test file)
• disableJasmineUncaughtExceptionTracking uses Vitest-compatible listeners
• allJsonSchemas uses import.meta.glob instead of webpack's require.context (no more JS + .d.ts pair)
• vitest is declared as a devDependency of @datadog/browser-core, whose test helpers now import it

Follow-up: migrate specs to the Vitest API (then drop the Jasmine shim).

⚠️ Written with an AI agent (Claude Code).

Test instructions

yarn
yarn test:unit                                # Vitest, unchanged
node scripts/check-licenses.ts                # dependencies and LICENSE-3rdparty.csv match
git grep -i karma -- ':!yarn.lock' ':!*CHANGELOG.md'   # only historical mentions left

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.
• Updated documentation and/or relevant AGENTS.md file

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum Salesforce	N/A	188.06 KiB	N/A	N/A	N/A
Rum	N/A	188.04 KiB	N/A	N/A	N/A
Rum-salesforce Profiler	N/A	8.35 KiB	N/A	N/A	N/A
Rum Profiler	8.35 KiB	8.35 KiB	0 B	0.00%	✅
Rum-salesforce Recorder	N/A	32.04 KiB	N/A	N/A	N/A
Rum Recorder	32.04 KiB	32.04 KiB	0 B	0.00%	✅
Logs	59.44 KiB	59.44 KiB	0 B	0.00%	✅
Rum Slim	145.83 KiB	145.83 KiB	0 B	0.00%	✅
Worker	N/A	22.96 KiB	N/A	N/A	N/A
Rum Shopify	N/A	218.48 KiB	N/A	N/A	N/A
Rum-shopify Profiler	N/A	8.35 KiB	N/A	N/A	N/A
Rum-shopify Recorder	N/A	4.85 KiB	N/A	N/A	N/A

[datadog-prod-us1-4]

✅ All CI checks and tests passed.

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 78.26% (+0.10%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: aa33c28 | Docs | View more details | Give us feedback!}