London | 26-ITP-Sep | Mahir Shah | Sprint 2 | Practice TDD

practice-tdd/count.js

@@ -1,3 +1,9 @@
 export function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (let i = 0; i < stringOfCharacters.length; i++) {
+    if (stringOfCharacters[i] === findCharacter) {
+      count += 1;
+    }
+  }
+  return count;
 }

practice-tdd/count.test.js

@@ -4,6 +4,32 @@ import { countChar } from "./count.js";
 // When the countChar function is called with these inputs,
 // Then it should:
 
+// Scenario: One Occurrence
+// Given the input string `str`,
+// And a character `char` that occurs one times in `str` (e.g., 'a' in 'abbbb'),
+// When the function is called with these inputs,
+// Then it should correctly count occurrences of `char`.
+test("should count one occurrence of a character at the beginning of a string", () => {
+  const str = "abbbb";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(1);
+});
+
+test("should count one occurrence of a character at the end of a string", () => {
+  const str = "bbbba";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(1);
+});
+
+test("should count one occurrence of a character in the middle of a string", () => {
+  const str = "bbabb";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(1);
+});
+
 // Scenario: Multiple Occurrences
 // Given the input string `str`,
 // And a character `char` that occurs one or more times in `str` (e.g., 'a' in 'aaaaa'),
@@ -17,8 +43,42 @@ test("should count multiple occurrences of a character", () => {
   expect(count).toEqual(5);
 });
 
+test("should count multiple occurrences of a character when mixed with other characters", () => {
+  const str = "ababa";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(3);
+});
+
+test("should count multiple occurrences of a character at the beginning and end of a string", () => {
+  const str = "abbba";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(2);
+});
+
+test("should count multiple occurrences of a character in the middle of a string", () => {
+  const str = "baaabaaabbb";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(7);
+});
+
 // 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 0 occurrences of a character", () => {
+  const str = "aaaaa";
+  const char = "b";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+test("should count 0 occurrences of a character for an empty string", () => {
+  const str = "";
+  const char = "b";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

practice-tdd/get-ordinal-number.js

@@ -1,3 +1,19 @@
 export function getOrdinalNumber(num) {
-  return "1st";
+  const numString = num.toString();
+  const lastDigit = numString.slice(-1);
+  const last2Digit = numString.slice(-2);
+
+  if (lastDigit === "1" && last2Digit !== "11") {
+    return numString + "st";
+  }
+
+  if (lastDigit === "2" && last2Digit !== "12") {
+    return numString + "nd";
+  }
+
+  if (lastDigit === "3" && last2Digit !== "13") {
+    return numString + "rd";
+  }
+
+  return numString + "th";
 }

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

@@ -18,3 +18,28 @@ 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(22)).toEqual("22nd");
+  expect(getOrdinalNumber(132)).toEqual("132nd");
+});
+
+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");
+});
+
+test("should append 'th' for numbers ending not ending with 1,2,3, except those ending with 11, 12, 13", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(166)).toEqual("166th");
+  expect(getOrdinalNumber(238)).toEqual("238th");
+  expect(getOrdinalNumber(211)).toEqual("211th");
+  expect(getOrdinalNumber(312)).toEqual("312th");
+  expect(getOrdinalNumber(413)).toEqual("413th");
+});

practice-tdd/repeat-str.js

@@ -1,5 +1,14 @@
-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("Error - invalid count number");
+  }
+
+  let repeatedStr = "";
+  for (let i = count; i > 0; i--) {
+    repeatedStr += str;
+  }
+
+  return repeatedStr;
 }

practice-tdd/repeat-str.test.js

@@ -16,17 +16,62 @@ test("should repeat the string count times", () => {
   expect(repeatedStr).toEqual("hellohellohello");
 });
 
+test("should return empty string when str is empty and count = 3", () => {
+  const str = "";
+  const count = 3;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
 // Case: handle count of 1:
 // 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, count = 1", () => {
+  const str = "hello";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("hello");
+});
+
+test("should return empty string when str is empty and count = 1", () => {
+  const str = "";
+  const count = 1;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
 // 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 empty string when count = 0", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeatStr(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
+test("should return empty string when string is empty and count = 0", () => {
+  const str = "";
+  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 return error when count < 0", () => {
+  const str = "hello";
+  const count = -5;
+  expect(() => repeatStr(str, count)).toThrow(/Error/);
+});
+
+test("should return error when count < 0 and  string is empty", () => {
+  const str = "";
+  const count = -5;
+  expect(() => repeatStr(str, count)).toThrow(/Error/);
+});