Silent failure as 200 Debugging Lab

Silent failure as 200HTTP/APIHardPreparing workspaceAutosaved

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Incident Dossier

Silent failure as 200

The fetch wrapper promises to never throw, but it satisfies that promise by mapping every transport-level failure to a 200 OK. Dashboards see green, alerting is silent, and the bug only shows up when an automated reconciliation notices that customer records are missing.

Initial failing signalTransport error returns 200 OKExpected non-200 status when the transport throws · received 200 OK with an empty body

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Run npm test.
Inspect the failing assertion: a thrown transport error returned status 200.
Trace the catch branch in safeFetch.
Translate the thrown error into a non-2xx response and preserve the message.

Focus Mode

Start

src/fetcher.js

Likely area

src/fetcher.js

Progressive hints

Hints reveal broad direction first, then narrow toward the suspect path without showing hidden tests or exact solution code.

TopicHTTP/API

DifficultyHard

Est. time22 min

Workspacecreating

Explorer

Preparing workspace files…

Evidence Map

Failing signal loaded from challenge API
Workspace files loaded from workspace API
Results rendered only after API run/submit

Autosaved

workspace

Outputread-onlyready$ workspace boot

Workspace booting...