London | 26-ITP-Jan | Kris Oldrini | Sprint 3 | Practice TDD

Sprint-3/2-practice-tdd/count.js

@@ -1,5 +1,9 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  const metaCharRegex = /[.^$*+?{}\[\]\\|()]/g;
+  const safeChar = findCharacter.replace(metaCharRegex, `\\$&`);
+  const charRegex = new RegExp(safeChar, "g");
+  const charArr = [...stringOfCharacters.matchAll(charRegex)];
+  return charArr.length;
 }
 
 module.exports = countChar;

Sprint-3/2-practice-tdd/count.test.js

@@ -22,3 +22,26 @@ 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 count 0 occurrences of a character", () => {
+  const str = "dog";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+test("should be case sensitive and return only occurrences of same case characters", () => {
+  const str = "Dodgers";
+  const char = "D";
+  const count = countChar(str, char);
+  expect(count).toEqual(1);
+});
+
+test("should count occurrences of regex metacharacters", () => {
+  const str = "a*b*c";
+  const char = "*";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
+
+// metacharacters . ^ $ * + ? { } [ ] \ | ( )

Sprint-3/2-practice-tdd/get-ordinal-number.js

@@ -1,5 +1,12 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  const lastTwoDigits = num % 100;
+  if (lastTwoDigits === 11 || lastTwoDigits === 12 || lastTwoDigits === 13)
+    return `${num}th`;
+  const lastDigit = num % 10;
+  if (lastDigit === 1) return `${num}st`;
+  if (lastDigit === 2) return `${num}nd`;
+  if (lastDigit === 3) return `${num}rd`;
+  return `${num}th`;
 }
 
 module.exports = getOrdinalNumber;

Sprint-3/2-practice-tdd/get-ordinal-number.test.js

@@ -18,3 +18,31 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+test("should append 'nd' for numbers ending with 2, except those ending with 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(42)).toEqual("42nd");
+  expect(getOrdinalNumber(782)).toEqual("782nd");
+});
+
+test("should append 'rd' for numbers ending with 3, except those ending with 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(93)).toEqual("93rd");
+  expect(getOrdinalNumber(7253)).toEqual("7253rd");
+});
+
+test("should append 'th' for numbers ending with numbers 0 or 4-9", () => {
+  expect(getOrdinalNumber(20)).toEqual("20th");
+  expect(getOrdinalNumber(75)).toEqual("75th");
+  expect(getOrdinalNumber(567)).toEqual("567th");
+  expect(getOrdinalNumber(2574)).toEqual("2574th");
+});
+
+test("should append 'th' for numbers ending with 11, 12, or 13", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(512)).toEqual("512th");
+  expect(getOrdinalNumber(113)).toEqual("113th");
+  expect(getOrdinalNumber(6411)).toEqual("6411th");
+});

Sprint-3/2-practice-tdd/repeat-str.js

@@ -1,5 +1,6 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  if (count < 0) throw new Error("Invalid format: count cannot be negative");
+  return str.repeat(count);
 }
 
 module.exports = repeatStr;

Sprint-3/2-practice-tdd/repeat-str.test.js

@@ -21,12 +21,33 @@ test("should repeat the string count times", () => {
 // When the repeatStr function is called with these inputs,
 // Then it should return the original `str` without repetition.
 
+test("should return the original string when count is 1", () => {
+  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 when count is 0", () => {
+  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 when count is negative", () => {
+  const str = "hello";
+  const count = -6;
+  const repeatedStr = () => repeatStr(str, count);
+  expect(repeatedStr).toThrow(/Invalid format/);
+});