// MISSION ARCHIVE //

CHALLENGE HALL

Select an anomaly, inspect the buggy logic, and submit your verified fix.

🎯 BUG OF THE DAY
ALL DIFFICULTIES EASY MEDIUM HARD INSANE
HARD
+500 XP

Debounce Trailing Execution Loss

A debounce function is losing its target execution arguments and context when the timer expires. Refactor debounce to preserve 'this' and the latest arguments passed to the debounced function.

⏱ 15m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
HARD
+500 XP

Object Key Memoizer Collision

A memoization wrapper casts arguments to string by key = args[0], which turns all objects into '[object Object]', causing different object inputs to return cached collision values! Fix key generation using JSON.stringify.

⏱ 15m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
HARD
+500 XP

Generator Infinite Loop Halt

A fibonacci sequence generator produces numbers, but lacks a maximum threshold or termination condition, causing callers attempting to consume it to enter an endless loop. Add a limit parameter.

⏱ 15m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
HARD
+500 XP

Prototype Pollution in Deep Merge

A recursive deepMerge utility merges user configs without checking key names, allowing attackers to pollute Object.prototype via '__proto__' or 'constructor'. Add validation to reject prototype pollution keys.

⏱ 15m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
INSANE
+1000 XP

EventEmitter Listener Removal Splice Bug

A custom EventBus implementation uses array.indexOf followed by splice inside a loop. When a listener unregisters itself during event dispatch, subsequent listeners in the array are skipped! Fix the dispatch array traversal.

⏱ 20m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
INSANE
+1000 XP

Circular Reference JSON Sanitizer

A payload logger crashes with 'TypeError: Converting circular structure to JSON'. Implement a custom JSON stringifier replacer function that replaces circular node references with '[Circular]'.

⏱ 20m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
INSANE
+1000 XP

Currying Function Arity Pipeline

A functional programming curry utility stops accumulating arguments too early when empty calls occur. Build a robust curry function that continuously returns a curried function until fn.length arguments have been received.

⏱ 20m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →
INSANE
+1000 XP

Immutable State Tree Reducer Mutation

A gaming state manager reducer performs deep updates by modifying properties directly on the existing state tree. In an immutable architecture, this breaks state time-travel. Refactor to return a clean new state object with updated branch values.

⏱ 20m limit ⚡ 0 Solves JAVASCRIPT
HUNT BUG →