update count.js

Author: FAprogrammerO

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

@@ -1,24 +1,48 @@
+// ═══════════════════════════════════════════════════════
+// 🎯 Personal Implementation: countChar Function Tests
+
+// Purpose: Test-first practice for counting character occurrences
+// Style: Gherkin-style BDD comments + Jest assertions
+// ═══════════════════════════════════════════════════════
+
 // implement a function countChar that counts the number of times a character occurs in a string
 const countChar = require("./count");
+
+// ───────────────────────────────────────────────────────
+// 📋 Specification:
 // Given a string `str` and a single character `char` to search for,
 // When the countChar function is called with these inputs,
-// Then it should:
+// Then it should return the number of times `char` appears in `str`.
+// ───────────────────────────────────────────────────────
+
+// ═══════════════════════════════════════════════════════
+// 🧪 Test Scenarios
+// ═══════════════════════════════════════════════════════
 
 // 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'),
 // When the function is called with these inputs,
 // Then it should correctly count occurrences of `char`.
-
 test("should count multiple occurrences of a character", () => {
-  const str = "aaaaa";
-  const char = "a";
+  const str = "aaaaa";      // 🎯 Input: repeated character
+  const char = "a";         // 🔍 Search for: 'a'
   const count = countChar(str, char);
-  expect(count).toEqual(5);
+  expect(count).toEqual(5); // ✅ Expect: 5 occurrences
 });
 
 // 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 return 0 for no occurence", () => {
+  const str = "asdf";       // 🎯 Input: no 'l' present
+  const char = "l";         // 🔍 Search for: 'l' (not in string)
+  const count = countChar(str, char);
+  expect(count).toEqual(0); // ✅ Expect: 0 occurrences
+});
+
+

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

@@ -1,5 +1,16 @@
 function getOrdinalNumber(num) {
-  return "1st";
+  let numberToString = String(num);
+  let numberLastDigit = numberToString.slice(-1);
+  let numberLast2Digits = numberToString.slice(-2);
+
+  if (numberLastDigit === "1" && numberLast2Digits !== "11")
+    return numberToString + "st";
+  if (numberLastDigit === "2" && numberLast2Digits !== "12")
+    return numberToString + "nd";
+  if (numberLastDigit === "3" && numberLast2Digits !== "13")
+    return numberToString + "rd";
+  return numberToString + "th";
 }
 
-module.exports = getOrdinalNumber;
+
+module.exports = getOrdinalNumber;

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

@@ -1,20 +1,47 @@
+
 const getOrdinalNumber = require("./get-ordinal-number");
-// In this week's prep, we started implementing getOrdinalNumber.
-
-// Continue testing and implementing getOrdinalNumber for additional cases.
-// Write your tests using Jest — remember to run your tests often for continual feedback.
-
-// To ensure thorough testing, we need broad scenarios that cover all possible cases.
-// Listing individual values, however, can quickly lead to an unmanageable number of test cases.
-// Instead of writing tests for individual numbers, consider grouping all possible input values
-// into meaningful categories. Then, select representative samples from each category to test.
-// This approach improves coverage and makes our tests easier to maintain.
-
-// Case 1: Numbers ending with 1 (but not 11)
-// When the number ends with 1, except those ending with 11,
-// Then the function should return a string by appending "st" to the number.
-test("should append 'st' for numbers ending with 1, except those ending with 11", () => {
-  expect(getOrdinalNumber(1)).toEqual("1st");
-  expect(getOrdinalNumber(21)).toEqual("21st");
-  expect(getOrdinalNumber(131)).toEqual("131st");
+
+// ───────────────────────────────────────────────────────
+// 📋 Rule Summary:
+// • 1 → "1st", 2 → "2nd", 3 → "3rd" (unless teen)
+// • 11, 12, 13 → always "th" (teen exception)
+// • All others → last digit determines suffix
+// ───────────────────────────────────────────────────────
+
+// ── Case 1: Numbers ending in 1 (excluding teens) → "st" ──
+test("appends 'st' to numbers ending in 1, except 11", () => {
+  expect(getOrdinalNumber(1)).toEqual("1st");    // single digit
+  expect(getOrdinalNumber(21)).toEqual("21st");  // double digit
+  expect(getOrdinalNumber(131)).toEqual("131st");// triple digit
+});
+
+// ── Case 2: Numbers ending in 2 (excluding teens) → "nd" ──
+test("appends 'nd' to numbers ending in 2, except 12", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(22)).toEqual("22nd");
+  expect(getOrdinalNumber(122)).toEqual("122nd");
+});
+
+// ── Case 3: Numbers ending in 3 (excluding teens) → "rd" ──
+test("appends 'rd' to numbers ending in 3, except 13", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(23)).toEqual("23rd");
+  expect(getOrdinalNumber(123)).toEqual("123rd");
+});
+
+// ── Case 4: Default "th" suffix (teens + digits 0,4-9) ──
+test("appends 'th' for teens (11-13) and digits 0,4-9", () => {
+  // Teen exceptions (critical edge case)
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+  expect(getOrdinalNumber(111)).toEqual("111th"); // larger teen
+  
+  // Default suffix digits
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(25)).toEqual("25th");
 });
+
+
+

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("negative counts are not valid");
+  return str.repeat(count);
 }
 
-module.exports = repeatStr;
+module.exports = repeatStr;

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

@@ -1,32 +1,37 @@
-// Implement a function repeatStr
 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:
 
-// Case: handle multiple repetitions:
-// Given a target string `str` and a positive integer `count` greater than 1,
-// When the repeatStr function is called with these inputs,
-// Then it should return a string that contains the original `str` repeated `count` times.
+// ───────────────────────────────────────────────────────
+// Rule Summary:
+// • count > 1 → str repeated count times ("hi", 3 → "hihihi")
+// • count = 1 → original string unchanged
+// • count = 0 → empty string ""
+// • count < 0 → throw error (invalid input)
+// ───────────────────────────────────────────────────────
 
-test("should repeat the string count times", () => {
-  const str = "hello";
-  const count = 3;
-  const repeatedStr = repeatStr(str, count);
-  expect(repeatedStr).toEqual("hellohellohello");
+// ── Case 1: Multiple repetitions (count > 1) ──
+test("repeats string correctly for count > 1", () => {
+  expect(repeatStr("hello", 3)).toEqual("hellohellohello");
+  expect(repeatStr("a", 5)).toEqual("aaaaa");
+  expect(repeatStr("xy", 2)).toEqual("xyxy");
 });
 
-// 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.
+// ── Case 2: Single repetition (count = 1) ──
+test("returns original string unchanged when count = 1", () => {
+  expect(repeatStr("bye", 1)).toEqual("bye");
+  expect(repeatStr("x", 1)).toEqual("x");
+  expect(repeatStr("test", 1)).toEqual("test");
+});
+
+// ── Case 3: Zero repetition (count = 0) ──
+test("returns empty string when count = 0", () => {
+  expect(repeatStr("no", 0)).toEqual("");
+  expect(repeatStr("anything", 0)).toEqual("");
+  expect(repeatStr("", 0)).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.
+// ── Case 4: Invalid input (negative count) ──
+test("throws error for negative count values", () => {
+  expect(() => repeatStr("str", -1)).toThrow("negative counts are not valid");
+  expect(() => repeatStr("x", -10)).toThrow("negative counts are not valid");
+});
 
-// 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.