Birmingham | 26-ITP-May | Ogbemi Mene | sprint 3 | 2-practice TDD coursework exercises

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

@@ -1,5 +1,13 @@
 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

@@ -22,3 +22,13 @@ 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.
+
+// to solve this issue, we will implement a test case that checks for the scenario where the character is not found in the string.
+// The test will call the countChar function with a string and a character that does not exist in that string, and it will assert that the returned count is 0.
+//  here is the code for the test case:
+test("should return 0 when character is not found", () => {
+  const str = "hello";
+  const char = "x";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});

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

@@ -1,5 +1,43 @@
-function getOrdinalNumber(num) {
-  return "1st";
+//function getOrdinalNumber(num) {
+  //return "1st";
+//}
+
+//module.exports = getOrdinalNumber;
+// this is a code i came up with to get the ordinal number of a given number. 
+// I will now write tests to check if it works correctly.
+
+//function getOrdinalNumber(n) {
+  //const pr = new Intl.PluralRules("en-US", { type: "ordinal" });
+  //const suffixes = { one: "st", two: "nd", few: "rd", other: "th" };
+  //const rule = pr.select(n);
+  //return `${n}${suffixes[rule]}`;
+//}
+
+// code without any API
+
+function getOrdinalNumber(n) {
+  // Pure arithmetic to get absolute value without Math.abs()
+  let positiveN;
+if (n < 0) {
+  positiveN = -n;
+} else {
+  positiveN = n;
+}
+
+  const lastTwoDigits = positiveN % 100;
+  const lastDigit = positiveN % 10;
+
+  // Teens exception: 11th, 12th, 13th
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 13) {
+    return `${n}th`;
+  }
+
+  // Standard endings
+  if (lastDigit === 1) return `${n}st`;
+  if (lastDigit === 2) return `${n}nd`;
+  if (lastDigit === 3) return `${n}rd`;
+
+  return `${n}th`;
 }
 
 module.exports = getOrdinalNumber;

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

@@ -18,3 +18,61 @@ test("should append 'st' for numbers ending with 1, except those ending with 11"
   expect(getOrdinalNumber(21)).toEqual("21st");
   expect(getOrdinalNumber(131)).toEqual("131st");
 });
+
+// here are more test cases for different scenarios
+
+describe("getOrdinalNumber", () => {
+  // Case 1: Already defined in your prompt
+  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");
+  });
+
+  // Case 2: Numbers ending with 2 (but not 12)
+  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(142)).toEqual("142nd");
+  });
+
+  // Case 3: Numbers ending with 3 (but not 13)
+  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(153)).toEqual("153rd");
+  });
+
+  // Case 4: Numbers ending with 11, 12, 13 (The exceptions)
+  test("should append 'th' for numbers ending in 11, 12, or 13", () => {
+    expect(getOrdinalNumber(11)).toEqual("11th");
+    expect(getOrdinalNumber(12)).toEqual("12th");
+    expect(getOrdinalNumber(13)).toEqual("13th");
+    expect(getOrdinalNumber(111)).toEqual("111th");
+    expect(getOrdinalNumber(112)).toEqual("112th");
+    expect(getOrdinalNumber(113)).toEqual("113th");
+  });
+
+  // Case 5: Numbers ending in 0, 4, 5, 6, 7, 8, or 9
+  describe("numbers ending with 0, 4, 5, 6, 7, 8, or 9", () => {
+    const defaultThCases = [
+      { endingDigit: 0, testValues: [0, 10, 20, 100, -10] },
+      { endingDigit: 4, testValues: [4, 24, 104, -4] },
+      { endingDigit: 5, testValues: [5, 25, 105, -5] },
+      { endingDigit: 6, testValues: [6, 26, 106, -6] },
+      { endingDigit: 7, testValues: [7, 27, 107, -7] },
+      { endingDigit: 8, testValues: [8, 28, 108, -8] },
+      { endingDigit: 9, testValues: [9, 29, 109, -9] },
+    ];
+
+
+    defaultThCases.forEach(({ endingDigit, testValues }) => {
+      test.each(testValues)(
+        `appends "th" to %i (representative for digit ${endingDigit})`,
+        (num) => {
+          expect(getOrdinalNumber(num)).toBe(`${num}th`);
+        }
+      );
+    });
+  });
+}); 

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

@@ -1,7 +1,15 @@
-function repeatStr() {
-  // 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";
+function repeatStr(str, count) {
+  // Native String.prototype.repeat throws a RangeError for negative counts
+  if (count < 0) {
+    throw new RangeError("Invalid count value");
+  }
+
+  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

@@ -30,3 +30,28 @@ 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, as negative counts are not valid.
+
+
+  // Case 1: Multiple repetitions
+  test("should repeat the string count times", () => {
+    const str = "hello";
+    const count = 3;
+    const repeatedStr = repeatStr(str, count);
+    expect(repeatedStr).toEqual("hellohellohello");
+  });
+
+  // Case 2: Count of 1
+  test("should return the original string when count is 1", () => {
+    expect(repeatStr("hello", 1)).toEqual("hello");
+  });
+
+  // Case 3: Count of 0
+  test("should return an empty string when count is 0", () => {
+    expect(repeatStr("hello", 0)).toEqual("");
+  });
+
+  // Case 4: Negative count
+  test("should throw an error when count is negative", () => {
+    expect(() => repeatStr("hello", -1)).toThrow(RangeError);
+  });
+