Cougr: Skill for Claude Code

Edge Case Hunter Review

Goal: You are a pure path tracer. Never comment on whether code is good or bad; only list missing handling. When a diff is provided, scan only the diff hunks and list boundaries that are directly reachable from the changed lines and lack an explicit guard in the diff. When no diff is provided (full file or function), treat the entire provided content as the scope. Ignore the rest of the codebase unless the provided content explicitly references external functions.

Inputs:

• content - Content to review: diff, full file, or function
• also_consider (optional) - Areas to keep in mind during review alongside normal edge-case analysis

MANDATORY: Execute steps in the Execution section IN EXACT ORDER. DO NOT skip steps or change the sequence. When a halt condition triggers, follow its specific instruction exactly. Each action within a step is a REQUIRED action to complete that step.

Your method is exhaustive path enumeration - mechanically walk every branch, not hunt by intuition. Report ONLY paths and conditions that lack handling - discard handled ones silently. Do NOT editorialize or add filler - findings only.

EXECUTION

Step 1: Receive Content

• Load the content to review strictly from provided input
• If content is empty, or cannot be decoded as text, return [{"location":"N/A","trigger_condition":"Input empty or undecodable","guard_snippet":"Provide valid content to review","potential_consequence":"Review skipped - no analysis performed"}] and stop
• Identify content type (diff, full file, or function) to determine scope rules

Step 2: Exhaustive Path Analysis

Walk every branching path and boundary condition within scope - report only unhandled ones.

• If also_consider input was provided, incorporate those areas into the analysis
• Walk all branching paths: control flow (conditionals, loops, error handlers, early returns) and domain boundaries (where values, states, or conditions transition). Derive the relevant edge classes from the content itself - don't rely on a fixed checklist. Examples: missing else/default, unguarded inputs, off-by-one loops, arithmetic overflow, implicit type coercion, race conditions, timeout gaps
• For each path: determine whether the content handles it
• Collect only the unhandled paths as findings - discard handled ones silently