Configuration

Threshold Configuration

The threshold option controls the spectral radius limit. Patterns with radius > threshold are considered unsafe.

import { check } from "resafe";

// Default threshold (1.0)
check("(a+)+$");  // ❌ Unsafe (radius 4.0 > 1.0)

// Higher threshold - more permissive
check("(a+)+$", { threshold: 5.0 });  // ✅ Safe (radius 4.0 < 5.0)

// Lower threshold - more strict
check("a+", { threshold: 0.5 }); // May flag some patterns

Silent Mode

Suppress console output while still getting analysis results:

const result = check("(a+)+$", { silent: true });

if (!result.safe) {
  console.error(`Pattern unsafe: radius ${result.radius.toFixed(2)}`);
}

Error Throwing

Use throwErr to prevent unsafe patterns from being used:

function createRegex(pattern: string): RegExp {
  check(pattern, { 
    throwErr: true, 
    silent: true,
    threshold: 1.0
  });
  
  return new RegExp(pattern);
}

try {
  const regex = createRegex("(a+)+$");
} catch (error) {
  console.error("Blocked unsafe regex:", error.message);
}