writing test for the given function and writing a function by test driven development

Author: Abduhasen

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

@@ -1,5 +1,11 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (let i = 0; i < stringOfCharacters.length; i++) {
+    if (stringOfCharacters[i] === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }
 
 module.exports = countChar;

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

@@ -16,9 +16,39 @@ test("should count multiple occurrences of a character", () => {
   const count = countChar(str, char);
   expect(count).toEqual(5);
 });
+test("should count multiple occurrences of a character", () => {
+  const str = "hello";
+  const char = "l";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
+test("should count multiple occurrences of a character", () => {
+  const str = "speed";
+  const char = "e";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
 
 // Scenario: No Occurrences
 // Given the input string `str`,
 // 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 multiple occurrences of a character", () => {
+  const str = "kkkk";
+  const char = "l";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+test("should count multiple occurrences of a character", () => {
+  const str = "bbbb";
+  const char = "c";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+test("should count multiple occurrences of a character", () => {
+  const str = "mmmmmzmze";
+  const char = "d";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

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

@@ -1,5 +1,19 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  let numberValue = num;
+  let lastDigit = numberValue % 10;
+  let lastTwoDigit = numberValue % 100;
+  if (lastTwoDigit === 11 || lastTwoDigit === 12 || lastTwoDigit === 13) {
+    return String(numberValue) + "th";
+  }
+  if (lastDigit === 1) {
+    return String(numberValue) + "st";
+  }
+  if (lastDigit === 2) {
+    return String(numberValue) + "nd";
+  }
+  if (lastDigit === 3) {
+    return String(numberValue) + "rd";
+  } else return String(numberValue) + "th";
 }
 
 module.exports = getOrdinalNumber;

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

@@ -18,3 +18,19 @@ 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(52)).toEqual("52nd");
+});
+// 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(33)).toEqual("33rd");
+  expect(getOrdinalNumber(133)).toEqual("133rd");
+});

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

@@ -1,7 +1,15 @@
-function repeatStr() {
+function repeatStr(str, num) {
+  let result = "";
   // 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";
+  for (let i = 0; i < num; i++) {
+    result += str;
+  }
+  if (num > 0) {
+    return result;
+  } else if (num === 0) {
+    return "";
+  } else throw new error();
 }
 
 module.exports = repeatStr;

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

@@ -20,13 +20,28 @@ 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 return the original string when count equal to 1", () => {
+  const str = "manchester";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("manchester");
+});
 // 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 the empty string when count equal to 0", () => {
+  const str = "ahmed";
+  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 negative values pass to it", () => {
+  expect(() => {
+    repeatedStr("hi", -3);
+  }).toThrow();
+});