format 12-hour time consistently with 2-digit hours

Sprint-2/5-stretch-extend/format-time.js

@@ -2,26 +2,33 @@ function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
   const minutes = time.slice(3, 5);
 
+  let formattedHour;
+  let period;
+
   if (hours === 0) {
-    // midnight
-    return `12:${minutes} am`;
+    formattedHour = "12";
+    period = "am";
   } else if (hours === 12) {
-    // noon
-    return `12:${minutes} pm`;
+    formattedHour = "12";
+    period = "pm";
   } else if (hours > 12) {
-    return `${hours - 12}:${minutes} pm`;
+    formattedHour = String(hours - 12).padStart(2, "0");
+    period = "pm";
   } else {
-    // 1am to 11am
-    return `${time} am`;
+    formattedHour = String(hours).padStart(2, "0");
+    period = "am";
   }
+
+  return `${formattedHour}:${minutes} ${period}`;
 }
 
+
 // Tests:
 const tests = [
   { input: "00:00", expected: "12:00 am" },
   { input: "08:00", expected: "08:00 am" },
   { input: "12:00", expected: "12:00 pm" },
-  { input: "15:30", expected: "3:30 pm" },
+  { input: "15:30", expected: "03:30 pm" },
   { input: "23:59", expected: "11:59 pm" },
   { input: "11:15", expected: "11:15 am" },
 ];
@@ -34,3 +41,4 @@ tests.forEach(({ input, expected }) => {
   );
 });
 
+