Algorithms must be thoroughly tested at boundary conditions and edge cases to prevent subtle bugs. Pay special attention to off-by-1 errors in mathematical calculations, empty collections, and boundary values that might cause unexpected behavior. Common edge cases to validate: - Mathematical boundaries (e.g., `Math.log10(10)` edge case) - Empty or single-element collections - Maximum/minimum values in ranges - Conditional logic branches with complex state Example from the codebase: ```javascript // Problematic - fails for totalTestCount === 10 const indexLength = Math.ceil(Math.log10(this.totalTestCount)); // Correct - handles the edge case properly const indexLength = Math.ceil(Math.log10(this.totalTestCount + 1)); ``` When implementing algorithms, create test cases that specifically target these boundary conditions. Consider reusing existing, well-tested algorithmic logic rather than reimplementing similar functionality, as proven algorithms are less likely to contain edge case bugs.