Safe parse function for typescript

safeParseInt.js

/**
 * Attempts to parse a string as an integer with validation and clamping.
 *
 * @param {unknown} str - The string to parse as an integer
 * @param {number} defaultValue - The value to return if parsing fails or validation fails
 * @param {string} [min=1] - The minimum allowed value (inclusive), defaults to 1
 * @param {number} [max] - The maximum allowed value (inclusive)
 * @returns {number} The parsed integer clamped to the range [min, max], or the default value if parsing fails
 *
 * @example
 * ```typescript
 * tryToParseInt("42", 0, 100, 1); // Returns 42
 * tryToParseInt("150", 0, 100, 1); // Returns 100 (clamped to max)
 * tryToParseInt("abc", 0, 100, 1); // Returns 0 (default value)
 * tryToParseInt("0", 10, 100, 1); // Returns 1 (clamped to min)
 * tryToParseInt(" ", 2, 100, 1); // Returns 2 (default value, whitespace input)
 * ```
 */
export function safeParseInt(str, defaultValue, min = 1, max = undefined) {
  try {
    if (typeof str !== "string") {
      return defaultValue; // Return default value if input is not a string
    }
    const num = parseInt(str, 10); // Always specify radix

    // Check if parsing failed or string wasn't purely numeric
    if (isNaN(num) || !str.trim() || !/^\d+$/.test(str.trim())) {
      return defaultValue;
    }

    // Clamp the value to the range [min, max] (if max is provided)
    return Math.max(min, max !== undefined ? Math.min(max, num) : num);
  } catch {
    return defaultValue;
  }
}

safeParseInt.ts

/**
 * Attempts to parse a string as an integer with validation and clamping.
 *
 * @param str - The string to parse as an integer
 * @param defaultValue - The value to return if parsing fails or validation fails
 * @param min - The minimum allowed value (inclusive), defaults to 1
 * @param max - The maximum allowed value (inclusive)
 * @returns The parsed integer clamped to the range [min, max], or the default value if parsing fails
 *
 * @example
 * ```typescript
 * tryToParseInt("42", 0, 100, 1); // Returns 42
 * tryToParseInt("150", 0, 100, 1); // Returns 100 (clamped to max)
 * tryToParseInt("abc", 0, 100, 1); // Returns 0 (default value)
 * tryToParseInt("0", 10, 100, 1); // Returns 1 (clamped to min)
 * tryToParseInt(" ", 2, 100, 1); // Returns 2 (default value, whitespace input)
 * ```
 */
export function safeParseInt(str: unknown, defaultValue: number, min = 1, max?: number): number {
  try {
    if (typeof str !== "string") {
      return defaultValue; // Return default value if input is not a string
    }
    const num = parseInt(str, 10); // Always specify radix

    // Check if parsing failed or string wasn't purely numeric
    if (isNaN(num) || !str.trim() || !/^\d+$/.test(str.trim())) {
      return defaultValue;
    }

    // Clamp the value to the range [min, max] (if max is provided)
    return Math.max(min, max !== undefined ? Math.min(max, num) : num);
  } catch {
    return defaultValue;
  }
}