Dotenv Empty String Truthy Debugging Lab

Dotenv Empty String TruthyConfig & EnvironmentMediumPreparing workspaceAutosaved

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Incident Dossier

Dotenv Empty String Truthy

Operators leave a maintenance kill switch blank in the runbook so it stays off, but the loader reads its empty-string default as a positive value. The flag is treated as 'on' even when the operator explicitly cleared it, and a routine deploy gets routed through the maintenance pipeline.

Initial failing signalexplicit blank maintenance flag is still considered onExpected isMaintenanceOn({ MAINTENANCE: '' }) === false · received isMaintenanceOn({ MAINTENANCE: '' }) === true

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Inspect the helper that reads a flag from the environment with a default.
See how an empty-string env value interacts with the default.
Confirm that an unset key uses the default and an explicitly cleared key does not.
Make the smallest correction that distinguishes 'unset' from 'cleared'.

Focus Mode

Start

src/env.js
src/flags.js

Likely area

src/env.js
src/flags.js

Progressive hints

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

TopicConfig & Environment

DifficultyMedium

Est. time15 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...