London | 26-ITP-January | Eugenie Ahangama | Sprint 3 | Practice TDD

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

@@ -1,5 +1,11 @@
 function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (const character of stringOfCharacters) {
+    if(character === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }
 
 module.exports = countChar;

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

@@ -22,3 +22,62 @@ 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 when character does not appear in string", () => {
+  expect(countChar("hello", "x")).toEqual(0);
+  expect(countChar("banana", "z")).toEqual(0);
+  // empty string
+  expect(countChar("", "a")).toEqual(0);
+});
+
+// Scenario: Single Occurence
+// Given a string where `char` appears exactly once,
+// When countChar is called,
+// Then it should return 1.
+test("should return 1 when character appears exactly once", () => {
+  expect(countChar("hello", "h")).toEqual(1);
+  expect(countChar("test", "e")).toEqual(1);
+  expect(countChar("xyz", "y")).toEqual(1);
+});
+
+// Scenario: Case Sensitivity
+// Given a string with mixed case letters, 
+// When countChar is called with a specific case,
+// Then it should count only exact matches (case-sensitive).
+test("should be case-sensitive when counting characters", () => {
+  expect(countChar("Hello", "H")).toEqual(1);
+  expect(countChar("Hello", "h")).toEqual(0);
+  expect(countChar("AAAaaa", "A")).toEqual(3);
+  expect(countChar("AAAaaa", "a")).toEqual(3);
+});
+
+// Scenario: Special Characters/Symbols
+// Given a string containing punctuation or emojis,
+// When counting a special character,
+// Then it should correctly identify and count it.
+test("should count special characters and emojis", () => {
+  expect(countChar("hello!!!", "!")).toEqual(3);
+  expect(countChar("smile 😊😊😊", "😊")).toEqual(3);
+});
+
+// Scenario: Longer Mixed String
+// Given a longer string with various characters and spaces,
+// When counting different characters,
+// Then it should return the correct count for each.
+test("should count correctly in longer mixed string", () => {
+  const str = "i am writing some jest tests right now";
+  // some, now
+  expect(countChar(str, "o")).toEqual(2);
+  // some, jest, tests
+  expect(countChar(str, "e")).toEqual(3);
+  // spaces
+  expect(countChar(str, " ")).toEqual(7);
+});
+
+// Scenario: Single Character String
+// Given a string containing only one character,
+// When countChar is called,
+// Then it should correctly handle matching or non-matching cases.
+test("should handle single character strings", () => {
+  expect(countChar("a", "a")).toEqual(1);
+  expect(countChar("b", "a")).toEqual(0);
+});

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

@@ -1,5 +1,23 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  // Last digit determines st/nd/rd for most numbers
+  const lastDigit = num % 10;
+  // Last two digits needed to handle special,
+  // teen cases (11th, 12th, 13th)
+  const lastTwo = num % 100;
+
+  // Special rule: numbers ending in 11, 12 or 13 always use "th"
+  if (lastTwo === 11 || lastTwo === 12 || lastTwo === 13) {
+    return num + "th";
+  }
+
+  // Ending in 1 → "st"
+  if (lastDigit === 1) return num + "st";
+  // Ending in 2 → "nd"
+  if (lastDigit === 2) return num + "nd";
+  // Ending in 3 → "rd"
+  if (lastDigit === 3) return num + "rd";
+  // All other endings (0, 4-9 and anything after teen check) → "th"
+  return num + "th";
 }
 
 module.exports = getOrdinalNumber;

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

@@ -18,3 +18,47 @@ 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 (except 12)
+// Given the number ends with 2 but not 12,
+// When getOrdinalNumber is called,
+// Then it should append "nd".
+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(102)).toEqual("102nd");
+});
+
+// Case 3: Numbers ending with 3 (except 13)
+// Given the number ends with 3 but not 13,
+// When getOrdinalNumber is called,
+// Then it should append "rd".
+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(103)).toEqual("103rd");
+});
+
+// Case 4: Numbers ending with 4-9, 0, or 11-19
+// Given the number ends with 4-9, 0, ot 11-19,
+// When getOrdinalNumber is called,
+// Then it should append "th".
+test("should append 'th' for numbers ending with 4-9, 0, or 11-19", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(5)).toEqual("5th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(20)).toEqual("20th");
+});
+
+// Case 5: Large numbers
+// Give a very large positive number,
+// When getOrdinalNumber is called,
+// Then it should still append the correct suffix based on the last digits.
+test("should handle large numbers correctly", () => {
+  expect(getOrdinalNumber(101)).toEqual("101st");
+  expect(getOrdinalNumber(112)).toEqual("112th");
+  expect(getOrdinalNumber(1000)).toEqual("1000th");
+});

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

@@ -1,5 +1,26 @@
-function repeatStr() {
-  return "hellohellohello";
+function repeatStr(str, count) {
+  // Reject negative counts - not valid for repetition
+  if (count < 0) {
+    throw new Error("Count cannot be negative");
+  }
+
+  // If count is 0, return empty string immediately
+  if (count === 0) {
+    return "";
+  }
+
+  // For count = 1, just return the original string
+  if (count === 1) {
+    return str;
+  }
+
+  // For count > 1: build the repeated string using a loop
+  let result = "";
+  for (let i = 0; i < count; i++) {
+    result += str;
+  }
+
+  return result;
 }
 
 module.exports = repeatStr;

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

@@ -20,13 +20,37 @@ 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 is 1", () => {
+  expect(repeatStr("hello", 1)).toEqual("hello");
+  expect(repeatStr("a", 1)).toEqual("a");
+  expect(repeatStr("", 1)).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 is 0", () => {
+  expect(repeatStr("hello", 0)).toEqual("");
+  expect(repeatStr("anything", 0)).toEqual("");
+  expect(repeatStr("", 0)).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 error when count is negative", () => {
+  expect(() => repeatStr("hello", -1)).toThrow();
+  expect(() => repeatStr("test", -5)).toThrow();
+  expect(() => repeatStr("", -3)).toThrow();
+});
+
+// Case: Handle positive count:
+// Given an empty string `str`and a positive integer `count`,
+// When the repeatStr function is called,
+// Then it should return an empty string
+test("should return empty string when input string is empty", () => {
+  expect(repeatStr("", 5)).toEqual("");
+  expect(repeatStr("", 1)).toEqual("");
+});