London | 26-ITP-May | Remi M. | Sprint 3 | Implement and Rewrite

Sprint-3/1-implement-and-rewrite-tests/implement/1-get-angle-type.js

@@ -16,6 +16,15 @@
 
 function getAngleType(angle) {
   // TODO: Implement this function
+  // Check invalid first - angles must be between 0 and 360 (exclusive)
+  if (angle <= 0 || angle >= 360) return "Invalid angle";
+  // Check exact values before ranges to avoid overlap
+  if (angle === 90) return "Right angle";
+  if (angle === 180) return "Straight angle";
+  // Now check ranges
+  if (angle < 90) return "Acute angle";
+  if (angle < 180) return "Obtuse angle";
+  return "Reflex angle"; // anything left must be between 180 and 360, which is reflex
 }
 
 // The line below allows us to load the getAngleType function into tests in other files.
@@ -33,5 +42,53 @@ function assertEquals(actualOutput, targetOutput) {
 
 // TODO: Write tests to cover all cases, including boundary and invalid cases.
 // Example: Identify Right Angles
+// // Right angle: only one possible value
 const right = getAngleType(90);
 assertEquals(right, "Right angle");
+
+// Acute angles: test a boundary (just above 0), a normal case, and a boundary (just below 90)
+const acute1 = getAngleType(1);
+assertEquals(acute1, "Acute angle"); // boundary: just above 0
+
+const acute2 = getAngleType(45);
+assertEquals(acute2, "Acute angle"); // normal acute angle
+
+const acute3 = getAngleType(89);
+assertEquals(acute3, "Acute angle"); // boundary: just below 90
+
+// Obtuse angles: boundary just above 90, normal, boundary just below 180
+const obtuse1 = getAngleType(91);
+assertEquals(obtuse1, "Obtuse angle"); // boundary: just above 90
+
+const obtuse2 = getAngleType(120);
+assertEquals(obtuse2, "Obtuse angle"); // normal obtuse angle
+
+const obtuse3 = getAngleType(179);
+assertEquals(obtuse3, "Obtuse angle"); // boundary: just below 180
+
+// Straight angle: only one possible value
+const straight = getAngleType(180);
+assertEquals(straight, "Straight angle");
+
+// Reflex angles: boundary just above 180, normal, boundary just below 360
+const reflex1 = getAngleType(181);
+assertEquals(reflex1, "Reflex angle"); // boundary: just above 180
+
+const reflex2 = getAngleType(270);
+assertEquals(reflex2, "Reflex angle"); // normal reflex angle
+
+const reflex3 = getAngleType(359);
+assertEquals(reflex3, "Reflex angle"); // boundary: just below 360
+
+// Invalid angles: exactly 0, exactly 360, negative, over 360
+const invalid1 = getAngleType(0);
+assertEquals(invalid1, "Invalid angle"); // boundary: exactly 0
+
+const invalid2 = getAngleType(360);
+assertEquals(invalid2, "Invalid angle"); // boundary: exactly 360
+
+const invalid3 = getAngleType(-10);
+assertEquals(invalid3, "Invalid angle"); // negative number
+
+const invalid4 = getAngleType(400);
+assertEquals(invalid4, "Invalid angle"); // over 360

Sprint-3/1-implement-and-rewrite-tests/implement/2-is-proper-fraction.js

@@ -12,6 +12,10 @@
 
 function isProperFraction(numerator, denominator) {
   // TODO: Implement this function
+  // a denominator of 0 is not a proper fraction - it is invalid. divison by 0 undefined.
+  if (denominator === 0) return false;
+  // Maths.abs handles negative numbers, -> e.g. -1/2 is a proper fraction, but 1/-2 is not.
+  return Math.abs(numerator) < Math.abs(denominator);
 }
 
 // The line below allows us to load the isProperFraction function into tests in other files.
@@ -31,3 +35,25 @@ function assertEquals(actualOutput, targetOutput) {
 
 // Example: 1/2 is a proper fraction
 assertEquals(isProperFraction(1, 2), true);
+
+// TODO: Write tests to cover all cases.
+// What combinations of numerators and denominators should you test?
+// Using inline style as the result doesn't need to be stored,
+// we only need to check if it equals the expected value
+
+// Example: 1/2 is a proper fraction
+assertEquals(isProperFraction(1, 2), true);
+
+// Proper fractions: numerator smaller than denominator
+assertEquals(isProperFraction(3, 4), true); // normal proper fraction
+assertEquals(isProperFraction(-1, 2), true); // negative numerator - still proper
+assertEquals(isProperFraction(0, 5), true); // zero numerator - 0/5 = 0, which is proper
+
+// Improper fractions: numerator greater than or equal to denominator
+assertEquals(isProperFraction(2, 1), false); // numerator bigger than denominator
+assertEquals(isProperFraction(5, 3), false); // normal improper fraction
+assertEquals(isProperFraction(4, 4), false); // boundary: equal - 4/4 = 1, a whole number not proper
+
+// Invalid: zero denominator - division by zero is undefined
+assertEquals(isProperFraction(1, 0), false);
+

Sprint-3/1-implement-and-rewrite-tests/implement/3-get-card-value.js

@@ -21,8 +21,49 @@
 // After you have implemented the function, write tests to cover all the cases, and
 // execute the code to ensure all tests pass.
 
+/**
+ * Returns the numerical value of a playing card.
+ *
+ * A standard deck has 4 suits: ♠ (spades), ♥ (hearts), ♦ (diamonds), ♣ (clubs)
+ * Each card is written as a rank followed by a suit symbol e.g. "A♠", "10♥", "K♦"
+ *
+ * @param {string} card - A string representing a playing card e.g. "A♠", "10♥", "K♦", "7♣"
+ * @returns {number} - The numerical value of the card:
+ *   - Ace ("A") returns 11
+ *   - Face cards ("J", "Q", "K") return 10
+ *   - Number cards ("2" to "10") return their numeric value
+ * @throws {Error} - If the card string is not in a valid format e.g. "invalid" or "1♠"
+ *
+ * @example
+ * getCardValue("A♠") // returns 11
+ * getCardValue("10♥") // returns 10
+ * getCardValue("K♦") // returns 10
+ * getCardValue("7♣") // returns 7
+ */
 function getCardValue(card) {
   // TODO: Implement this function
+  // NEW: The suit symbol (♠ ♥ ♦ ♣) always takes up 2 characters in JavaScript
+  // slice(0, -2) means "give me everything except the last 2 characters"
+  // so "A♠" becomes "A", "10♥" becomes "10", "K♦" becomes "K"
+  // MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice
+  const rank = card.slice(0, -1);
+
+  // ✨ NEW: Ace is always worth 11
+  if (rank === "A") return 11;
+
+  // ✨ NEW: Face cards - Jack, Queen and King are all worth 10
+  if (rank === "J" || rank === "Q" || rank === "K") return 10;
+
+  // ✨ NEW: Number() converts a string like "9" into the actual number 9
+  // so we can check if it falls in the valid range of 2 to 10
+  // MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number
+  const numValue = Number(rank);
+  if (numValue >= 2 && numValue <= 10) return numValue;
+
+  // ✨ NEW: If we reach this line, none of the above matched
+  // throw stops the function and sends an error back to whoever called it
+  // MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw
+  throw new Error(`Invalid card: ${card}`);
 }
 
 // The line below allows us to load the getCardValue function into tests in other files.
@@ -38,17 +79,52 @@ function assertEquals(actualOutput, targetOutput) {
 }
 
 // TODO: Write tests to cover all outcomes, including throwing errors for invalid cards.
-// Examples:
-assertEquals(getCardValue("9♠"), 9);
+
+// Ace cards - always 11 regardless of suit
+assertEquals(getCardValue("A♠"), 11);
+assertEquals(getCardValue("A♥"), 11);
+
+// Number cards - return their face value as a number
+assertEquals(getCardValue("2♦"), 2); // boundary: lowest number card
+assertEquals(getCardValue("9♣"), 9);
+assertEquals(getCardValue("10♥"), 10); // boundary: highest number card
+
+// Face cards - Jack, Queen and King all return 10
+assertEquals(getCardValue("J♣"), 10);
+assertEquals(getCardValue("Q♦"), 10);
+assertEquals(getCardValue("K♠"), 10);
 
 // Handling invalid cards
+// try/catch lets us test that an error IS thrown
+// try: runs the code. catch: catches the error if one is thrown
+// MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch
 try {
   getCardValue("invalid");
-
   // This line will not be reached if an error is thrown as expected
-  console.error("Error was not thrown for invalid card 😢");
+  console.error("Error was not thrown for invalid card ");
 } catch (e) {
-  console.log("Error thrown for invalid card 🎉");
+  console.log("Error thrown for invalid card ");
 }
 
 // What other invalid card cases can you think of?
+
+try {
+  getCardValue("1♠"); // 1 is not a valid rank - valid ranks are 2 through A
+  console.error("Error was not thrown for rank 1 ");
+} catch (e) {
+  console.log("Error thrown for rank 1 ");
+}
+
+try {
+  getCardValue("11♥"); // 11 is not a valid rank - valid ranks are 2 through A
+  console.error("Error was not thrown for rank 11 ");
+} catch (e) {
+  console.log("Error thrown for rank 11 ");
+}
+
+try {
+  getCardValue("A"); // missing suit
+  console.error("Error was not thrown for missing suit ");
+} catch (e) {
+  console.log("Error thrown for missing suit ");
+}

Sprint-3/1-implement-and-rewrite-tests/rewrite-tests-with-jest/1-get-angle-type.test.js

@@ -2,6 +2,9 @@
 // We will use the same function, but write tests for it using Jest in this file.
 const getAngleType = require("../implement/1-get-angle-type");
 
+// Jest docs: https://jestjs.io/docs/getting-started
+// freeCodeCamp intro to testing: https://www.freecodecamp.org/news/how-to-start-unit-testing-javascript
+
 // TODO: Write tests in Jest syntax to cover all cases/outcomes,
 // including boundary and invalid cases.
 
@@ -14,7 +17,33 @@ test(`should return "Acute angle" when (0 < angle < 90)`, () => {
 });
 
 // Case 2: Right angle
+test(`should return "Right angle" when angle is exactly 90`, () => {
+  expect(getAngleType(90)).toEqual("Right angle");
+});
+
 // Case 3: Obtuse angles
+test(`should return "Obtuse angle" when (90 < angle < 180)`, () => {
+  expect(getAngleType(91)).toEqual("Obtuse angle"); // boundary: just above 90
+  expect(getAngleType(120)).toEqual("Obtuse angle"); // normal obtuse angle
+  expect(getAngleType(179)).toEqual("Obtuse angle"); // boundary: just below 180
+});
+
 // Case 4: Straight angle
+test(`should return "Straight angle" when angle is exactly 180`, () => {
+  expect(getAngleType(180)).toEqual("Straight angle");
+});
+
 // Case 5: Reflex angles
+test(`should return "Reflex angle" when (180 < angle < 360)`, () => {
+  expect(getAngleType(181)).toEqual("Reflex angle"); // boundary: just above 180
+  expect(getAngleType(270)).toEqual("Reflex angle"); // normal reflex angle
+  expect(getAngleType(359)).toEqual("Reflex angle"); // boundary: just below 360
+});
+
 // Case 6: Invalid angles
+test(`should return "Invalid angle" for angles outside valid range`, () => {
+  expect(getAngleType(0)).toEqual("Invalid angle"); // boundary: exactly 0
+  expect(getAngleType(360)).toEqual("Invalid angle"); // boundary: exactly 360
+  expect(getAngleType(-10)).toEqual("Invalid angle"); // negative number
+  expect(getAngleType(400)).toEqual("Invalid angle"); // over 360
+});

Sprint-3/1-implement-and-rewrite-tests/rewrite-tests-with-jest/2-is-proper-fraction.test.js

@@ -8,3 +8,22 @@ const isProperFraction = require("../implement/2-is-proper-fraction");
 test(`should return false when denominator is zero`, () => {
   expect(isProperFraction(1, 0)).toEqual(false);
 });
+
+// Proper fractions: numerator smaller than denominator
+test("should return true for a proper fraction", () => {
+  expect(isProperFraction(1, 2)).toEqual(true); // basic proper fraction
+  expect(isProperFraction(3, 4)).toEqual(true);
+  expect(isProperFraction(-1, 2)).toEqual(true); // negative numerator still proper
+  expect(isProperFraction(0, 5)).toEqual(true); // 0/5 = 0, which is proper
+});
+
+// Improper fractions: numerator greater than denominator
+test("should return false for an improper fraction", () => {
+  expect(isProperFraction(2, 1)).toEqual(false);
+  expect(isProperFraction(5, 3)).toEqual(false);
+});
+
+// Boundary: equal numerator and denominator - 4/4 = 1, a whole number not a fraction
+test("should return false when numerator equals denominator", () => {
+  expect(isProperFraction(4, 4)).toEqual(false);
+});

Sprint-3/1-implement-and-rewrite-tests/rewrite-tests-with-jest/3-get-card-value.test.js

@@ -7,6 +7,7 @@ const getCardValue = require("../implement/3-get-card-value");
 // Case 1: Ace (A)
 test(`Should return 11 when given an ace card`, () => {
   expect(getCardValue("A♠")).toEqual(11);
+  expect(getCardValue("A♥")).toEqual(11);
 });
 
 // Suggestion: Group the remaining test data into these categories:
@@ -18,3 +19,25 @@ test(`Should return 11 when given an ace card`, () => {
 // please refer to the Jest documentation:
 // https://jestjs.io/docs/expect#tothrowerror
 
+// Number cards -> return their numeric value (2-10)
+test("should return the numeric value for number cards", () => {
+  expect(getCardValue("2♦")).toEqual(2); // boundary: lowest number card
+  expect(getCardValue("9♣")).toEqual(9);
+  expect(getCardValue("10♥")).toEqual(10); // boundary: highest number card
+});
+
+//Face cards -> Jack, Queen and King are all worth 10
+test("should return 10 for face cards (J, Q, K)", () => {
+  expect(getCardValue("J♣")).toEqual(10);
+  expect(getCardValue("Q♦")).toEqual(10);
+  expect(getCardValue("K♠")).toEqual(10);
+});
+
+// Invalid cards -> function should throw an error
+// We wrap the call in () => so Jest can catch the error without crashing the test
+// MDN on arrow functions: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions
+test("should throw an error for invalid cards", () => {
+  expect(() => getCardValue("invalid")).toThrow();
+  expect(() => getCardValue("1♠")).toThrow(); // 1 is not a valid rank
+  expect(() => getCardValue("")).toThrow(); // empty string
+});