🐛 tolerate Cypress.env throwing under allowCypressEnv: false

[bcaudan]

Motivation

A telemetry error is observed in customer data:

CypressError: Cypress.env() does not work when allowCypressEnv is set to false. ... The variable being accessed was: traceId

The SDK reads window.Cypress.env('traceId') at boot in ciVisibilityContext.ts as a secondary transport for the CI Visibility test execution id (the primary is the datadog-ci-visibility-test-execution-id cookie). Under Cypress 15.10+ with allowCypressEnv: false, the call itself throws regardless of whether a value was set.

The legacy env path is still used: it serves customers on dd-trace-js < 5.88.0 (where the plugin still wrote via Cypress.env). Removing the read would silently break correlation for them.

Changes

• Wrap the Cypress.env('traceId') read in try/catch in ciVisibilityContext.ts so the throw no longer bubbles up
• Emit a display.warn(...) only when the env read actually throws, prompting customers to upgrade dd-trace-js >= 5.88.0 (the version that switched the writer to the cookie via dd-trace-js#7600).

Test instructions

• yarn test:unit --spec packages/rum-core/src/domain/contexts/ciVisibilityContext.spec.ts — 9 specs pass (5 existing + 4 new).

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	179.26 KiB	179.43 KiB	+170 B	+0.09%	✅
Rum Profiler	6.17 KiB	6.17 KiB	0 B	0.00%	✅
Rum Recorder	27.03 KiB	27.03 KiB	0 B	0.00%	✅
Logs	56.67 KiB	56.67 KiB	0 B	0.00%	✅
Rum Slim	135.13 KiB	135.29 KiB	+167 B	+0.12%	✅
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	0.0077	0.0067	-12.99%
RUM - add action	0.0234	0.0196	-16.24%
RUM - add error	0.0226	0.0179	-20.80%
RUM - add timing	0.0048	0.0042	-12.50%
RUM - start view	0.0194	0.0173	-10.82%
RUM - start/stop session replay recording	0.0013	0.001	-23.08%
Logs - log message	0.0262	0.0221	-15.65%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	32.33 KiB	32.01 KiB	-327 B
RUM - add action	107.66 KiB	105.51 KiB	-2.15 KiB
RUM - add timing	32.27 KiB	31.84 KiB	-445 B
RUM - add error	92.08 KiB	97.48 KiB	+5.40 KiB
RUM - start/stop session replay recording	32.31 KiB	30.76 KiB	-1.54 KiB
RUM - start view	494.14 KiB	483.60 KiB	-10.54 KiB
Logs - log message	106.69 KiB	93.84 KiB	-12.85 KiB

🔗 RealWorld

[datadog-prod-us1-5]

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 81.82%
• Overall Coverage: 77.04% (+0.03%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: ac47794 | Docs | Datadog PR Page | Give us feedback!}