Loop Mutates the Source Array Debugging Lab

Loop Mutates the Source ArrayEvents & ConcurrencyMediumPreparing workspaceAutosaved

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Incident Dossier

Loop Mutates the Source Array

A job runner skips jobs that are marked skip:true. Operators report that some non-skipped jobs are silently dropped from the result and the original jobs array shrinks under their feet.

Initial failing signalprocessJobs drops non-skipped jobs and mutates the inputExpected completed ids are exactly [1, 3, 5] and the jobs array is unchanged · received completed ids are [1, 3] and the input array shrank

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Run npm test.
Trace how processJobs handles a job with skip:true.
Consider what happens to the iterator index when the array shifts under it.
Make the runner keep the input intact and visit every non-skipped job.

Focus Mode

Start

src/jobs.js

Likely area

src/jobs.js

Progressive hints

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

TopicEvents & Concurrency

DifficultyMedium

Est. time18 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...