fix: Preserve the cause of a thrown error in RESTController.handleError

[Stovedal]

Pull Request

• Report security issues confidentially.
• Any contribution is under this license.

Issue

Network errors are hard to debug due to discarded error cause.

Closes #3150.

Approach

Copy cause onto the ParseError after it is constructed, so it applies to both branches.

Tasks

• Add tests

Summary by CodeRabbit

• Bug Fixes
  • Network errors now retain their underlying cause when reported, providing more context about what went wrong. Existing error reporting and rejection behavior remain unchanged.

[parse-github-assistant]

I will reformat the title to use the proper commit message syntax.

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: e2bc80c0-7143-413c-ada0-b7df2daa324b

📥 Commits

Reviewing files that changed from the base of the PR and between 560db76 and 009bf42.

📒 Files selected for processing: 2

• src/RESTController.ts
• src/__tests__/RESTController-test.js

Included review availability: This review used your included allowance. Your plan provides up to 4 included reviews per hour; 3 remain after this review.

📝 Walkthrough

RESTController.handleError now copies a defined cause from an input error to the resulting ParseError. A RESTController.request test verifies that the same cause remains on the rejection.

Changes: Error cause preservation

Layer / File(s)	Summary
Preserve and test error causes src/RESTController.ts, src/__tests__/RESTController-test.js	handleError copies a defined cause to the constructed ParseError. A request test checks that the thrown error’s cause remains on the rejection.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Severity of issue fixed: Low

Merge Risk: ⚪ Minimal · up to 009bf

REST request failures retain a defined cause without changing their existing ParseError rejection behavior. No actionable merge risk remains.

Security architecture risk: ⚪ Minimal · up to 009bf

The change preserves diagnostic data on existing request errors without changing request authority or rejection behavior. No material security risk was identified in the changed behavior.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The demonstrated exposure change is additional error data delivered to existing SDK request callers. A configured server can supply that data in an error response, and a transport failure can supply it locally. The inspected change does not establish cross-tenant access, additional privileges, or automatic transmission of the retained cause.

Trust Boundaries and Controls

• observed — The added operation assigns input data to a fixed cause property on a newly constructed error. It does not evaluate that data or use it for authentication, destination selection, or retry decisions. Existing credential selection and request dispatch are unchanged by the PR.

Pre-merge checks: 7

Passed checks: 7 passed

Check name	Status	Explanation
Title check		The title begins with the required fix: prefix, uses a capitalized first letter after the prefix, and accurately describes the change.
Description check		The description includes the required Pull Request, Issue, Approach, and Tasks sections. It explains the problem, describes the implementation, links issue #3150, and confirms that tests were added.
Linked Issues check		Issue #3150 requires RESTController.handleError to preserve a thrown network error's cause without changing the existing message and code behavior. At the reviewed head, handleError constructs `…
Out of Scope Changes check		The reviewed changes are limited to the RESTController.handleError cause assignment and a focused regression test for preserved network-error causes. Both changes directly support issue #3150. No un…
Docstring Coverage		No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 2…
Security Check		No security vulnerability is introduced. The only production change copies an existing errorJSON.cause to the newly created ParseError when it is defined. The cause comes from the already handled …
Engage In Review Feedback		The current review produced zero actionable findings, and no CodeRabbit review threads were returned. Therefore, the pull request had no review feedback that required engagement, implementation, or re…

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