🐛 add support for arbitrary Error causes

[mormubis]

Motivation

Fixes #3839

Changes

If the cause of an error is non-error, it will retrieve the same information as addError(error.cause) and add it to the causes.

Test instructions

All tests passed.

Checklist

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

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage
• Patch Coverage: 100.00%
• Total Coverage: 92.68% (+0.00%)

View detailed report

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[cit-pr-commenter]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	164.13 KiB	164.28 KiB	+158 B	+0.09%	✅
Rum Profiler	4.84 KiB	4.84 KiB	0 B	0.00%	✅
Rum Recorder	19.62 KiB	19.62 KiB	0 B	0.00%	✅
Logs	55.91 KiB	56.07 KiB	+165 B	+0.29%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	121.39 KiB	121.56 KiB	+165 B	+0.13%	✅
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	0.0052	0.0045	-13.46%
RUM - add action	0.0166	0.0135	-18.67%
RUM - add error	0.0123	0.014	+13.82%
RUM - add timing	0.0038	0.0038	0.00%
RUM - start view	0.0043	0.0041	-4.65%
RUM - start/stop session replay recording	0.0007	0.001	+42.86%
Logs - log message	0.0153	0.0163	+6.54%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	25.97 KiB	26.13 KiB	+155 B
RUM - add action	48.71 KiB	49.30 KiB	+604 B
RUM - add timing	24.62 KiB	23.98 KiB	-660 B
RUM - add error	54.02 KiB	56.98 KiB	+2.96 KiB
RUM - start/stop session replay recording	24.42 KiB	24.00 KiB	-432 B
RUM - start view	424.89 KiB	423.04 KiB	-1.86 KiB
Logs - log message	46.09 KiB	43.59 KiB	-2.50 KiB

🔗 RealWorld

[mormubis]

/to-staging

[dd-devflow-routing-codex]

View all feedbacks in Devflow UI.

2025-09-19 13:30:50 UTC ℹ️ Start processing command /to-staging

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2025-09-19 13:30:58 UTC ℹ️ Branch Integration: starting soon, merge expected in approximately 13m (p90)

Commit 73dedf8cc3 will soon be integrated into staging-38.

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2025-09-19 13:44:44 UTC ℹ️ Branch Integration: this commit was successfully integrated

Commit 73dedf8cc3 has been merged into staging-38 in merge commit 18489a1875.

Check out the triggered pipeline on Gitlab 🦊

If you need to revert this integration, you can use the following command: /code revert-integration -b staging-38

[bcaudan]

💬 suggestion: ‏For reporting thrown string we also stringify the message since we add a prefix the quotes act like a separator, ex: Uncaught "string cause".
Not sure the quotes add much value in this case.

[mormubis]

I didn't want to affect how they look in the UI. Also, it improves the readability when they are objects.

Thoughts?

[bcaudan]

❓ question: ‏that sounds ok to me but I wonder if it is a choice you made or if it is based on spec.

[mormubis]

There are no specifications regarding how to handle complaint objects that are not errors. I made this decision to prevent a plain object with a cause field from causing any issues.