Implement formatAs12HourClock function with comprehensive tests for time conversion

Author: moses77-boop

format-clock-edge-cases/README.md

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+In your prep, you looked this `formatAs12HourClock` function:
+
+```js
+function formatAs12HourClock(time) {
+
+  const hours = Number(time.slice(0, 2));
+
+  if (hours > 12) {
+    return `${hours - 12}:00 pm`;
+  }
+  return `${time} am`;
+}
+```
+
+It still has bugs. Think of as many edge-cases as you can with this code. Write tests for all of them, and fix this code so that it works correctly for all valid inputs. You don't need to worry about invalid inputs (e.g. `"25:00"`).

format-clock-edge-cases/timeConverter.js

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+// function formatAs12HourClock(time) {
+
+//   const hours = Number(time.slice(0, 2));
+
+//   if (hours > 12) {
+//     return `${hours - 12}:00 pm`;
+//   }
+//   return `${time} am`;
+// }
+
+// export {formatAs12HourClock};
+
+function formatAs12HourClock(time){
+  const [hourPart, minutePart] = time.split(":");
+  const hours = Number(hourPart);
+
+  let period;
+  if(hours < 12){
+    period = "am";
+  } else {
+    period = "pm";
+  }
+
+  let displayHour = hours % 12;
+  if(displayHour === 0){
+    displayHour = 12;
+  } 
+  return `${displayHour}:${minutePart}${period}`;
+}
+export {formatAs12HourClock};
+console.log(formatAs12HourClock("08:40"))

format-clock-edge-cases/timeConverter.test.js

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+import {formatAs12HourClock} from "./timeConverter.js";
+import assert from "node:assert";
+import test from "node:test";
+
+test("correctly convert time after 12:00", () => {
+    assert.equal(formatAs12HourClock("23:00"), "11:00pm");
+});
+
+test("converts a single-digit morning hour and drops leading zero", () => {
+    assert.equal(formatAs12HourClock("08:00"), "8:00am");
+})
+test("converts exactly to midnight", () => {
+    assert.equal(formatAs12HourClock("00:00"), "12:00am");
+})
+test("converts time just after midnight", () => {
+    assert.equal(formatAs12HourClock("00:30"), "12:30am");
+})
+test("converts the last minute before noon", () => {
+    assert.equal(formatAs12HourClock("11:59"), "11:59am");
+})
+test("converts exact noon to pm", () => {
+    assert.equal(formatAs12HourClock("12:00"), "12:00pm");
+})
+test("convert time just after noon", () => {
+    assert.equal(formatAs12HourClock("12:30"), "12:30pm");
+})
+test("converts the first afternoon hour", () => {
+    assert.equal(formatAs12HourClock("13:00"), "1:00pm");
+})
+test("converts late evening hour", () => {
+    assert.equal(formatAs12HourClock("23:00"), "11:00pm");
+})
+test("converts last minute of the day", () => {
+    assert.equal(formatAs12HourClock("23:59"), "11:59pm");
+})
+test("preserves minutes with leading zero", () => {
+    assert.equal(formatAs12HourClock("09:05"), "9:05am");
+})
+test("preserves non-zero minutes", () => {
+    assert.equal(formatAs12HourClock("14:45"), "2:45pm");
+})