Address comments

Author: minggangw

lib/utils.js

@@ -41,16 +41,21 @@ function detectUbuntuCodename() {
  * The comparison uses the formula:
  *   abs(a - b) <= max(rtol * max(abs(a), abs(b)), atol)
  *
+ * Implementation checks:
+ *   1. Absolute tolerance: abs(a - b) <= atol
+ *   2. Relative tolerance: abs(a - b) / max(abs(a), abs(b)) <= rtol
+ *
  * @param {number} a - The first number to compare
  * @param {number} b - The second number to compare
  * @param {number} [rtol=1e-9] - The relative tolerance parameter (default: 1e-9)
  * @param {number} [atol=0.0] - The absolute tolerance parameter (default: 0.0)
  * @returns {boolean} True if the numbers are close within the tolerance
  *
  * @example
- * isClose(1.0, 1.0) // true
- * isClose(1.0, 1.1, 0.01) // false - difference 0.1 > 0.01 * max(1.0, 1.1) = 0.011
- * isClose(10, 10.00001, 1e-6) // true - difference 0.00001 <= 1e-6 * 10 = 0.00001
+ * isClose(1.0, 1.0) // true - exact equality
+ * isClose(1.0, 1.1, 0.01) // false - relative diff: 0.1/1.1 ≈ 0.091 > 0.01
+ * isClose(10, 10.00001, 1e-6) // true - relative diff: 0.00001/10 = 1e-6 <= 1e-6
+ * isClose(0, 0.05, 0, 0.1) // true - absolute diff: 0.05 <= 0.1 (atol)
  */
 function isClose(a, b, rtol = 1e-9, atol = 0.0) {
   // Handle exact equality
@@ -72,6 +77,12 @@ function isClose(a, b, rtol = 1e-9, atol = 0.0) {
 
   // Check relative tolerance
   const relativeScaler = Math.max(Math.abs(a), Math.abs(b));
+
+  // Handle division by zero when both values are zero or very close to zero
+  if (relativeScaler === 0) {
+    return true; // Both are zero, already handled by absolute tolerance
+  }
+
   const relativeDiff = absDiff / relativeScaler;
 
   return rtol >= relativeDiff;