London | 26 ITP SEP | Russom Gebremeskel | Sprint 2 | Practice TDD

practice-tdd/count.js

@@ -1,3 +1,9 @@
 export function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (const char of stringOfCharacters) {
+    if (char === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }

practice-tdd/count.test.js

@@ -22,3 +22,10 @@ test("should count multiple occurrences of a character", () => {
 // And a character `char` that does not exist within `str`.
 // When the function is called with these inputs,
 // Then it should return 0, indicating that no occurrences of `char` were found.
+
+test("should return 0 for a character with no occurrences", () => {
+  const str = "aaaaa";
+  const char = "b";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

practice-tdd/get-ordinal-number.js

@@ -1,3 +1,15 @@
 export function getOrdinalNumber(num) {
-  return "1st";
+  const lastDigit = num % 10;
+  const lastTwoDigit = num % 100;
+
+  if (lastDigit === 1 && lastTwoDigit !== 11) {
+    return `${num}st`;
+  }
+  if (lastDigit === 2 && lastTwoDigit !== 12) {
+    return `${num}nd`;
+  }
+  if (lastDigit === 3 && lastTwoDigit !== 13) {
+    return `${num}rd`;
+  }
+  return `${num}th`;
 }

practice-tdd/get-ordinal-number.test.js

@@ -18,3 +18,48 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+// Case 2: Numbers ending with 2 (but not 12)
+// When the number ends with 2, except those ending with 12,
+// Then the function should return a string by appending "nd" to the number.
+test("should append 'nd' for numbers ending with 2, except those ending with 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(22)).toEqual("22nd");
+  expect(getOrdinalNumber(132)).toEqual("132nd");
+});
+
+// Case 3: Numbers ending with 3 (but not 13)
+// When the number ends with 3, except those ending with 13,
+// Then the function should return a string by appending "rd" to the number.
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(23)).toEqual("23rd");
+  expect(getOrdinalNumber(133)).toEqual("133rd");
+});
+
+// Case 4: Exception for 11, 12 and 13.
+// When a number ends with 11, 12 and 13,
+// Then the function should return a string by appending "th" not st, nd or rd.
+test("should append 'th' for numbers ending with 11, 12 and 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+});
+
+// Case 5: Numbers ending with 4 to 9.
+// When the number ends with 4 to 9,
+// Then the function should return a string by appending "th" to the number.
+test("should append 'th' for numbers ending with 4 to 9", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(14)).toEqual("14th");
+  expect(getOrdinalNumber(144)).toEqual("144th");
+});
+
+// Case 6: Numbers ending with 0.
+// When the number ends with 0,
+// Then the function should return a string by appending "th" to the number.
+test("should append 'th' for numbers ending with 0", () => {
+  expect(getOrdinalNumber(0)).toEqual("0th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(100)).toEqual("100th");
+});

practice-tdd/repeat-str.js

@@ -1,5 +1,13 @@
-export function repeatStr() {
+export function repeatStr(str, count) {
   // Your implementation of this function must *not* call String.prototype.repeat (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat).
   // The goal is to re-implement that function, not to use it.
-  return "hellohellohello";
+  if (count < 0) {
+    throw new Error("Count must not be negative");
+  }
+
+  let repeat = "";
+  for (let i = 0; i < count; i++) {
+    repeat += str;
+  }
+  return repeat;
 }

practice-tdd/repeat-str.test.js

@@ -20,13 +20,30 @@ test("should repeat the string count times", () => {
 // Given a target string `str` and a `count` equal to 1,
 // When the repeatStr function is called with these inputs,
 // Then it should return the original `str` without repetition.
+test("should repeat the string count times", () => {
+  const str = "hello";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("hello");
+});
 
 // Case: Handle count of 0:
 // Given a target string `str` and a `count` equal to 0,
 // When the repeatStr function is called with these inputs,
 // Then it should return an empty string.
+test("should return an empty string", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
 
 // Case: Handle negative count:
 // Given a target string `str` and a negative integer `count`,
 // When the repeatStr function is called with these inputs,
 // Then it should throw an error, as negative counts are not valid.
+test("should throw an error", () => {
+  const str = "hello";
+  const count = -1;
+  expect(() => repeatStr(str, count)).toThrow("Count must not be negative");
+});