fix(api): harden toError against circular-reference payloads

[mpiton]

Summary

Hardens the toError error-normalization helper in src/api/client.ts against circular-reference payloads. Previously, a circular object rejected by invoke would throw TypeError: Converting circular structure to JSON from inside the tauriInvoke catch block, masking the original IPC failure. Closes #142.

Why

When a Rust error from Tauri IPC is enriched or re-wrapped in a way that creates a circular reference before rejection, JSON.stringify(err) synchronously throws a TypeError instead of succeeding. The uncaught throw occurs inside the tauriInvoke catch handler, replacing the original error with a normalization failure — unhelpful for debugging.

Changes

• Wrap JSON.stringify(err) in try/catch in toError() function.
• Fallback to String(err) when JSON serialization fails (covers circular refs and other stringify edge cases).
• Three new regression tests: circular object rejection, plain-object stringification, string-rejection wrapping.
• Update CHANGELOG.md under [Unreleased] > Fixed scope api.

Testing

npx vitest run src/api/__tests__/client.test.ts
# Test Files  1 passed (1)
# Tests  10 passed (10)

npx vitest run
# Test Files  82 passed (82)
# Tests  671 passed (671)

All TS linting and formatting pass. oxlint reports 0 warnings.

Related Issues

• Closes fix(api): harden toError against circular-reference payloads #142

Checklist

• Tests added and passing locally
• CHANGELOG updated
• No linting/formatting issues
• Self-reviewed

---

Summary by cubic

Hardened toError to handle circular and non-serializable payloads so tauriInvoke surfaces the real IPC error instead of JSON errors or blank messages. Closes #142.

• Bug Fixes
  • Guard JSON.stringify(err) and fall back to String(err); coalesce undefined stringify results to avoid blank Error.message.
  • Preserve string rejections; JSON-stringify plain objects.
  • Added tests for circular objects, plain-object JSON, string rejections, undefined, and function/symbol rejections.

^{Written for commit 18ec66f. Summary will update on new commits.}

Summary by CodeRabbit

• Bug Fixes

  • Improved API error handling to prevent serialization issues (including circular or otherwise unserializable payloads) from masking original error messages, ensuring meaningful, non-blank error text.

• Tests

  • Added tests covering error rejection behavior across circular references, plain objects, strings, undefined and other edge payloads to guard against regressions.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: e62a7cef-e67f-4dd4-8c22-e5afb3450f03

📥 Commits

Reviewing files that changed from the base of the PR and between 9e0dbb2 and 18ec66f.

📒 Files selected for processing (3)

• CHANGELOG.md
• src/api/__tests__/client.test.ts
• src/api/client.ts

🚧 Files skipped from review as they are similar to previous changes (3)

• src/api/client.ts
• src/api/tests/client.test.ts
• CHANGELOG.md

---

📝 Walkthrough

Walkthrough

The toError helper in src/api/client.ts is hardened against circular-reference and other non-stringifiable rejection payloads by wrapping JSON.stringify in a try/catch, explicitly handling string inputs, and falling back to String(err) when needed. Tests and CHANGELOG entry added to cover the behaviors.

Changes

Error Handling Robustness

Layer / File(s)	Summary
Core Implementation src/api/client.ts	toError now returns new Error(err) for string inputs, attempts JSON.stringify(err) inside a try/catch, and falls back to String(err) if stringification throws or yields undefined.
Tests src/api/__tests__/client.test.ts	Added tests asserting circular-reference rejection payloads do not cause JSON/type errors, plain-object rejections are stringified, string rejections are rethrown as raw strings, and undefined/non-stringifiable payloads produce non-blank error messages.
Changelog CHANGELOG.md	Unreleased → Fixed entry documents the defensive try/catch around JSON.stringify, fallback to String(err), and added regression tests for circular and edge-case rejection payloads.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

I’m a rabbit who caught a loop in flight,
Wrapped it in try/catch and set it right.
Strings stay tidy, circles don’t bite,
Fallbacks shine softly in the night. 🐇✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: hardening the toError function to handle circular-reference payloads, which is the primary focus of the PR.
Linked Issues check	✅ Passed	The PR fully addresses all coding requirements from issue #142: handles Error instances, string inputs, attempts JSON.stringify with try/catch, and falls back to String(err) to avoid throwing on circular references.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to issue #142: modifications to toError in src/api/client.ts, test coverage for circular-reference and edge cases, and CHANGELOG documentation.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/issue-142-toError-circular

---

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/api/client.ts`:
- Around line 7-10: The current error-wrapping code returns new
Error(JSON.stringify(err)) but doesn't handle JSON.stringify returning undefined
(e.g., for undefined, symbols, or functions), producing a blank Error.message;
update the block in src/api/client.ts that handles err so you first call const
msg = JSON.stringify(err); if msg === undefined then use String(err) (or
fallback like Object.prototype.toString.call(err)) and finally return new
Error(msgOrFallback) while keeping the existing catch fallback for thrown
stringify errors.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: cc9e6104-f15f-4666-8793-daf34d622df3

📥 Commits

Reviewing files that changed from the base of the PR and between 53b272f and 9e0dbb2.

📒 Files selected for processing (3)

• CHANGELOG.md
• src/api/__tests__/client.test.ts
• src/api/client.ts

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/api/client.ts">

<violation number="1" location="src/api/client.ts:8">
P3: Handle the `JSON.stringify` non-throwing `undefined` case before constructing the `Error`; otherwise some rejected payloads produce an empty error message.</violation>
</file>

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[codspeed-hq]

Merging this PR will not alter performance

✅ 26 untouched benchmarks

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_{Comparing fix/issue-142-toError-circular (18ec66f) with main (53b272f)}