🔥 Remove old cookie migration

[thomas-lebeau]

Motivation

The old cookie migration code (tryOldCookiesMigration) handled upgrading from a legacy cookie format (_dd, _dd_r, _dd_l) to the current unified _dd_s cookie. This migration has been in place long enough that any users still on the old format have either upgraded or are no longer active. For v7, this legacy compatibility code is no longer needed.

Changes

• Remove oldCookiesMigration.ts and its spec file (oldCookiesMigration.spec.ts) from packages/core
• Remove the tryOldCookiesMigration call from initCookieStrategy in sessionInCookie.ts
• The old cookie names _dd, _dd_r, and _dd_l are no longer read or migrated

Test instructions

1. Verify unit tests pass: yarn test:unit
2. Confirm no references to tryOldCookiesMigration or oldCookiesMigration remain in the codebase
3. Verify session initialization works correctly without the migration step

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	172.25 KiB	172.01 KiB	-246 B	-0.14%	✅
Rum Profiler	4.29 KiB	4.29 KiB	0 B	0.00%	✅
Rum Recorder	24.71 KiB	24.71 KiB	0 B	0.00%	✅
Logs	56.93 KiB	56.69 KiB	-246 B	-0.42%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	128.75 KiB	128.51 KiB	-246 B	-0.19%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Pending...

🧠 Memory Performance

Pending...

🔗 RealWorld

[datadog-datadog-prod-us1]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 80.18%
• Overall Coverage: 77.12% (-0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 2b1b5d8 | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[chatgpt-codex-connector]

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