Complete Sprint 3 section 5: extend

Author: BrianY315

Sprint-3/5-stretch-extend/format-time.js

@@ -2,24 +2,31 @@
 // Make sure to do the prep before you do the coursework
 // Your task is to write tests for as many different groups of input data or edge cases as you can, and fix any bugs you find.
 
+const assert = require("node:assert/strict");
+
 function formatAs12HourClock(time) {
-  const hours = Number(time.slice(0, 2));
-  if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+  if (typeof time !== "string" || !/^(?:[01]\d|2[0-3]):[0-5]\d$/.test(time)) {
+    throw new RangeError("time must be a valid 24-hour time in HH:MM format");
   }
-  return `${time} am`;
+
+  const hours = Number(time.slice(0, 2));
+  const displayHours = String(hours % 12 || 12).padStart(2, "0");
+  const minutes = time.slice(3);
+  const period = hours < 12 ? "am" : "pm";
+
+  return `${displayHours}:${minutes} ${period}`;
 }
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
-console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
-);
+assert.equal(formatAs12HourClock("00:00"), "12:00 am");
+assert.equal(formatAs12HourClock("00:05"), "12:05 am");
+assert.equal(formatAs12HourClock("08:00"), "08:00 am");
+assert.equal(formatAs12HourClock("11:59"), "11:59 am");
+assert.equal(formatAs12HourClock("12:00"), "12:00 pm");
+assert.equal(formatAs12HourClock("12:45"), "12:45 pm");
+assert.equal(formatAs12HourClock("13:07"), "01:07 pm");
+assert.equal(formatAs12HourClock("23:59"), "11:59 pm");
+assert.throws(() => formatAs12HourClock("24:00"), RangeError);
+assert.throws(() => formatAs12HourClock("12:60"), RangeError);
+assert.throws(() => formatAs12HourClock("8:00"), RangeError);
 
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
-console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
-);
+console.log("All formatAs12HourClock tests passed.");