Manchester | 25-ITP-May | Fithi Teklom | Sprint 3 | 3-stretch

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

@@ -3,3 +3,19 @@ function countChar(stringOfCharacters, findCharacter) {
 }
 
 module.exports = countChar;
+
+const countChar = require('../countChar');
+
+describe('countChar()', () => {
+  test('always returns 5', () => {
+    expect(countChar('anything', 'a')).toBe(5);
+  });
+
+  test('still returns 5 with empty string', () => {
+    expect(countChar('', 'z')).toBe(5);
+  });
+
+  test('still returns 5 with special characters', () => {
+    expect(countChar('!!!', '!')).toBe(5);
+  });
+});

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

@@ -1,5 +1,16 @@
 // implement a function countChar that counts the number of times a character occurs in a string
 const countChar = require("./count");
+
+function countChar(stringOfCharacters, findCharacter) {
+  let count = 0;
+  for (let char of stringOfCharacters) {
+    if (char === findCharacter) count++;
+  }
+  return count;
+}
+
+module.exports = countChar;
+
 // Given a string str and a single character char to search for,
 // When the countChar function is called with these inputs,
 // Then it should:
@@ -16,6 +27,36 @@ test("should count multiple occurrences of a character", () => {
   const count = countChar(str, char);
   expect(count).toEqual(5);
 });
+test("should return 0 when the character is not found", () => {
+  const str = "hello";
+  const char = "z";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Scenario: Case Sensitivity
+// It should be case-sensitive, meaning 'A' != 'a'.
+test("should be case-sensitive when counting characters", () => {
+  const str = "Banana";
+  expect(countChar(str, "a")).toEqual(3);
+  expect(countChar(str, "A")).toEqual(0);
+});
+
+// Scenario: Empty String
+// It should return 0 when the input string is empty.
+test("should return 0 when the input string is empty", () => {
+  const str = "";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
+
+// Scenario: Special Characters
+// It should correctly count spaces and punctuation.
+test("should count special characters like spaces or punctuation", () => {
+  expect(countChar("a b a b", " ")).toEqual(2);
+  expect(countChar("wow!!!", "!")).toEqual(3);
+});
 
 // Scenario: No Occurrences
 // Given the input string str,

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

@@ -1,5 +1,61 @@
+
 function getOrdinalNumber(num) {
-  return "1st";
+  const remainder10 = num % 10;
+  const remainder100 = num % 100;
+
+  if (remainder100 >= 11 && remainder100 <= 13) {
+    return `${num}th`;
+  }
+
+  switch (remainder10) {
+    case 1:
+      return `${num}st`;
+    case 2:
+      return `${num}nd`;
+    case 3:
+      return `${num}rd`;
+    default:
+      return `${num}th`;
+  }
 }
 
 module.exports = getOrdinalNumber;
+
+
+const getOrdinalNumber = require("./getOrdinalNumber");
+
+describe("getOrdinalNumber()", () => {
+  test("should return '1st' for 1", () => {
+    expect(getOrdinalNumber(1)).toBe("1st");
+  });
+
+  test("should return '2nd' for 2", () => {
+    expect(getOrdinalNumber(2)).toBe("2nd");
+  });
+
+  test("should return '3rd' for 3", () => {
+    expect(getOrdinalNumber(3)).toBe("3rd");
+  });
+
+  test("should return '4th' for 4", () => {
+    expect(getOrdinalNumber(4)).toBe("4th");
+  });
+
+  test("should return '11th', '12th', '13th' for special cases", () => {
+    expect(getOrdinalNumber(11)).toBe("11th");
+    expect(getOrdinalNumber(12)).toBe("12th");
+    expect(getOrdinalNumber(13)).toBe("13th");
+  });
+
+  test("should return correct suffixes for 21, 22, 23", () => {
+    expect(getOrdinalNumber(21)).toBe("21st");
+    expect(getOrdinalNumber(22)).toBe("22nd");
+    expect(getOrdinalNumber(23)).toBe("23rd");
+  });
+
+  test("should return '111th' for numbers ending with 11, 12, 13 even if larger", () => {
+    expect(getOrdinalNumber(111)).toBe("111th");
+    expect(getOrdinalNumber(112)).toBe("112th");
+    expect(getOrdinalNumber(113)).toBe("113th");
+  });
+});

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

@@ -1,4 +1,11 @@
 const getOrdinalNumber = require("./get-ordinal-number");
+
+function getOrdinalNumber(num) {
+  return "1st";
+}
+
+module.exports = getOrdinalNumber;
+
 // In this week's prep, we started implementing getOrdinalNumber
 
 // continue testing and implementing getOrdinalNumber for additional cases

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

@@ -3,6 +3,14 @@ const repeatStr = require("./repeat-str");
 // Given a target string str and a positive integer count,
 // When the repeatStr function is called with these inputs,
 // Then it should:
+function repeat(str, count) {
+  if (count < 0) {
+    throw new Error("Count must be a non-negative integer");
+  }
+  return str.repeat(count);
+}
+
+module.exports = repeat;
 
 // case: repeat String:
 // Given a target string str and a positive integer count,
@@ -30,3 +38,35 @@ test("should repeat the string count times", () => {
 // 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 or return an appropriate error message, as negative counts are not valid.
+const repeat = require("./repeat");
+
+// Case 1: Repeat string multiple times
+test("should repeat the string count times", () => {
+  const str = "hello";
+  const count = 3;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("hellohellohello");
+});
+
+// Case 2: Handle count of 1
+test("should return the original string when count is 1", () => {
+  const str = "world";
+  const count = 1;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("world");
+});
+
+// Case 3: Handle count of 0
+test("should return an empty string when count is 0", () => {
+  const str = "test";
+  const count = 0;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
+// Case 4: Negative count
+test("should throw an error when count is negative", () => {
+  const str = "oops";
+  const count = -2;
+  expect(() => repeat(str, count)).toThrow("Count must be a non-negative integer");
+});

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

@@ -0,0 +1,11 @@
+const repeat = require("./repeat");
+
+function repeat() {
+  return "hellohellohello";
+}
+
+module.exports = repeat;
+
+test("should repeat the given word three times", () => {
+  expect(repeat("hi", 3)).toBe("hihihi");
+});

Sprint-3/3-stretch/ validateCreditCard.js

@@ -0,0 +1,25 @@
+function validateCreditCard(number) {
+  const numStr = String(number);
+
+  // Must be exactly 16 digits, only numbers
+  if (!/^\d{16}$/.test(numStr)) return false;
+
+  // Must contain at least two different digits
+  const uniqueDigits = new Set(numStr);
+  if (uniqueDigits.size < 2) return false;
+
+  // Last digit must be even
+  const lastDigit = Number(numStr[numStr.length - 1]);
+  if (lastDigit % 2 !== 0) return false;
+
+  // Sum must be greater than 16
+  const sum = numStr
+    .split("")
+    .map(Number)
+    .reduce((a, b) => a + b, 0);
+  if (sum <= 16) return false;
+
+  return true;
+}
+
+module.exports = validateCreditCard;

Sprint-3/3-stretch/card-validator.md.js

@@ -0,0 +1,59 @@
+/**
+ * Validates a credit card number based on specific rules:
+ * - Must be 16 digits
+ * - Must have at least two different digits
+ * - Final digit must be even
+ * - Sum of all digits must be greater than 16
+ * 
+ * @param {string} cardNumber - The credit card number to validate
+ * @returns {boolean} - true if valid, false if invalid
+ */
+function validateCreditCard(cardNumber) {
+    // Rule 1: Check if length is exactly 16 digits and all are numbers
+    if (!/^\d{16}$/.test(cardNumber)) {
+        return false;
+    }
+
+    // Convert string to array of numbers
+    const digits = cardNumber.split('').map(Number);
+
+    // Rule 2: Check for at least two different digits
+    const uniqueDigits = new Set(digits);
+    if (uniqueDigits.size < 2) {
+        return false;
+    }
+
+    // Rule 3: Check if the final digit is even
+    if (digits[digits.length - 1] % 2 !== 0) {
+        return false;
+    }
+
+    // Rule 4: Check if sum of all digits is greater than 16
+    const sum = digits.reduce((acc, val) => acc + val, 0);
+    if (sum <= 16) {
+        return false;
+    }
+
+    // All rules passed
+    return true;
+}
+
+// Example usage:
+console.log(validateCreditCard("9999777788880000")); // true
+console.log(validateCreditCard("6666666666661666")); // true
+console.log(validateCreditCard("a92332119c011112")); // false
+console.log(validateCreditCard("4444444444444444")); // false
+console.log(validateCreditCard("1111111111111110")); // false
+console.log(validateCreditCard("6666666666666661")); // false
+
+module.exports = validateCreditCard;
+
+const validateCreditCard = require('./credit-card-validator');
+
+test("valid credit card number", () => {
+    expect(validateCreditCard("9999777788880000")).toBe(true);
+});
+
+test("invalid credit card number (all same digits)", () => {
+    expect(validateCreditCard("4444444444444444")).toBe(false);
+});

Sprint-3/3-stretch/find.js

@@ -20,6 +20,14 @@ console.log(find("code your future", "z"));
 // Pay particular attention to the following:
 
 // a) How the index variable updates during the call to find
+//The variable index starts at 0 and increases by 1 every time the loop runs (index++).
+//It keeps track of the current position in the string.
 // b) What is the if statement used to check
+//The if statement checks whether the current character (str[index]) is equal to the one we’re searching for (char).
+//If it is, we immediately return index.
 // c) Why is index++ being used?
+//It moves to the next character in the string during each loop iteration.
+//Without it, the loop would never move forward — it would keep checking the same character forever (infinite loop 🔁
 // d) What is the condition index < str.length used for?
+//That’s the loop condition — it keeps the loop running as long as index is less than the length of the string.
+//Once index equals str.length, it means we’ve checked every character, and the loop stops.

Sprint-3/3-stretch/password-validator.js

@@ -3,4 +3,8 @@ function passwordValidator(password) {
 }
 
 
-module.exports = passwordValidator;
+module.exports = passwordValidator;
+
+// password.length < 5 → rejects short passwords.
+
+// Returns true only if the password passes all checks.

Sprint-3/3-stretch/password-validator.test.js

@@ -14,6 +14,35 @@ To be valid, a password must:
 
 You must breakdown this problem in order to solve it. Find one test case first and get that working
 */
+const previousPasswords = [];//Create an array to store previous passwords
+
+function isValidPassword(password) {
+  // Rule 1: At least 5 characters
+  if (password.length < 5) return false;
+
+  // Rule 2: At least one uppercase letter
+  if (!/[A-Z]/.test(password)) return false;
+
+  // Rule 3: At least one lowercase letter
+  if (!/[a-z]/.test(password)) return false;
+
+  // Rule 4: At least one number
+  if (!/[0-9]/.test(password)) return false;
+
+  // Rule 5: At least one special symbol ! # $ % . * &
+  if (!/[!#$%.*&]/.test(password)) return false;
+
+  // Rule 6: Must not be a previous password
+  if (previousPasswords.includes(password)) return false;
+
+  // If all checks pass, save password and return true
+  previousPasswords.push(password);
+  return true;
+}
+
+module.exports = isValidPassword;
+
+
 const isValidPassword = require("./password-validator");
 test("password has at least 5 characters", () => {
     // Arrange

Sprint-3/3-stretch/validateCreditCard.test.js

@@ -0,0 +1,22 @@
+const validateCreditCard = require("./validateCreditCard");
+
+test("valid credit card numbers should return true", () => {
+  expect(validateCreditCard("9999777788880000")).toBe(true);
+  expect(validateCreditCard("6666666666661666")).toBe(true);
+});
+
+test("invalid cards with letters should return false", () => {
+  expect(validateCreditCard("a92332119c011112")).toBe(false);
+});
+
+test("invalid cards with all same digits should return false", () => {
+  expect(validateCreditCard("4444444444444444")).toBe(false);
+});
+
+test("invalid cards with sum less than 16 should return false", () => {
+  expect(validateCreditCard("1111111111111110")).toBe(false);
+});
+
+test("invalid cards with odd final digit should return false", () => {
+  expect(validateCreditCard("6666666666666661")).toBe(false);
+});