💥 [RUM-14058] Use tree walker for action name computation

[cy-moi]

Motivation

We have tested tree walker approach and the previous approach of action name computation back to back, it seems that the risk of switching to tree walker is low (results are identical on staging). The tree walker approach is more secure and efficient. It also gives alignment between action name and SR rendered texts.

Changes

Remove feature flag of using treewalker
Remove legacy action name compuation approach
Fix test cases by removing the FF mock

Test instructions

Should pass CI

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.

[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	170.35 KiB	169.90 KiB	-469 B	-0.27%	✅
Rum Profiler	4.69 KiB	4.69 KiB	0 B	0.00%	✅
Rum Recorder	24.91 KiB	24.91 KiB	0 B	0.00%	✅
Logs	56.38 KiB	56.31 KiB	-68 B	-0.12%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	127.63 KiB	127.18 KiB	-461 B	-0.35%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
RUM - add global context	0.0063	0.01	+58.73%
RUM - add action	0.0136	0.0251	+84.56%
RUM - add error	0.0142	0.0214	+50.70%
RUM - add timing	0.0029	0.0044	+51.72%
RUM - start view	0.0124	0.018	+45.16%
RUM - start/stop session replay recording	0.0007	0.0018	+157.14%
Logs - log message	0.0146	0.0962	+558.90%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	26.93 KiB	32.31 KiB	+5.39 KiB
RUM - add action	115.44 KiB	55.61 KiB	-59.83 KiB
RUM - add timing	25.89 KiB	31.97 KiB	+6.08 KiB
RUM - add error	120.19 KiB	61.95 KiB	-58.24 KiB
RUM - start/stop session replay recording	25.57 KiB	31.87 KiB	+6.30 KiB
RUM - start view	506.11 KiB	453.98 KiB	-52.13 KiB
Logs - log message	45.61 KiB	50.75 KiB	+5.14 KiB

🔗 RealWorld

[BenoitZugmeyer]

/to-staging

[gh-worker-devflow-routing-ef8351]

View all feedbacks in Devflow UI.

2026-02-23 09:16:27 UTC ℹ️ Start processing command /to-staging

---

2026-02-23 09:16:34 UTC ℹ️ Branch Integration: starting soon, merge expected in approximately 0s (p90)

Commit 77d6150a9f will soon be integrated into staging-09.

---

2026-02-23 09:30:53 UTC ℹ️ Branch Integration: this commit was successfully integrated

Commit 77d6150a9f has been merged into staging-09 in merge commit d181f5111a.

Check out the triggered DDCI request.

If you need to revert this integration, you can use the following command: /code revert-integration -b staging-09

[datadog-datadog-prod-us1]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 0.00%
• Overall Coverage: 76.94% (-0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 77d6150 | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[BenoitZugmeyer]

/code revert-integration -b staging-09

[gh-worker-devflow-routing-ef8351]

View all feedbacks in Devflow UI.

2026-02-23 12:43:40 UTC ℹ️ Start processing command /code revert-integration -b staging-09
If you need support, contact us on Slack #devflow!

---

2026-02-23 12:43:45 UTC ❌ Devflow: /code revert-integration -b staging-09

An error occurred when reverting d181f51.

You can manually perform the revert with the following commands:

git fetch origin staging-09
git switch -c df-revert-ee7fbf94f4337c4393a41da2c8b2744dc1be5976000e29da7550cf92cd46e204-from-staging-09 staging-09
git revert --no-commit d181f5111a -m 1
git commit -m "Revert d181f5111a"

Then you can push and create a pull request to merge your commit.

Details

Merge conflict

To get help about command usage, write /code revert-integration --help

If you need support, contact us on Slack #devflow with those details!

[sethfowler-datadog]

Looks great; glad to see this one getting enabled by default!