Birmingham | ITP-Jan-26 | Ayodeji Ayorinde | Sprint 1| Coursework/Sprint1

Sprint-1/fix/median.js

@@ -5,10 +5,30 @@
 // Hint: Please consider scenarios when 'list' doesn't have numbers (the function is expected to return null)
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
+
 function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+  // Check it is an array
+  if (!Array.isArray(list)) return null;
+
+  // Pull out numbers
+  const nums = list.filter(n => typeof n === "number" && !Number.isNaN(n));
+
+  // If no numbers, return null
+  if (nums.length === 0) return null;
+
+  // MODERN FIX: Use .toSorted() to avoid mutating the original array
+  const sorted = nums.toSorted((a, b) => a - b);
+
+  const len = sorted.length;
+  const mid = Math.floor(len / 2);
+
+  // If length is odd, take middle element
+  if (len % 2 === 1) {
+    return sorted[mid];
+  }
+
+  // If length is even, take average of two middle elements
+  return (sorted[mid - 1] + sorted[mid]) / 2;
 }
 
-module.exports = calculateMedian;
+module.exports = calculateMedian;

Sprint-1/implement/dedupe.js

@@ -1 +1,8 @@
-function dedupe() {}
+function dedupe(arr) {
+    // (Though requirements suggest it will be an array)
+    if (!Array.isArray(arr)) return [];
+    // The spread operator [...] preserves the first-occurrence order
+    return [...new Set(arr)];
+}
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -1,4 +1,41 @@
+
+
 const dedupe = require("./dedupe.js");
+
+describe("dedupe()", () => {
+    // Acceptance Criteria 1
+    test("given an empty array, it returns an empty array", () => {
+        expect(dedupe([])).toEqual([]);
+    });
+
+    // Acceptance Criteria 2
+    test("given an array with no duplicates, it returns a copy of the original array", () => {
+        const input = [1, 2, 3, "a", "b"];
+        const result = dedupe(input);
+        expect(result).toEqual(input);
+        // Ensure it's a new reference (a copy)
+        expect(result).not.toBe(input);
+    });
+
+    // Acceptance Criteria 3 & 4: Numbers
+    test("it should remove duplicate numbers and preserve first occurrence order", () => {
+        expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]);
+        expect(dedupe([1, 2, 1])).toEqual([1, 2]);
+    });
+
+    // Acceptance Criteria 3 & 4: Strings
+    test("it should remove duplicate strings and preserve first occurrence order", () => {
+        expect(dedupe(['a', 'a', 'a', 'b', 'b', 'c'])).toEqual(['a', 'b', 'c']);
+    });
+
+    // Mixed types edge case
+    test("it should handle mixed strings and numbers correctly", () => {
+        expect(dedupe([1, "1", 1, "a", "a"])).toEqual([1, "1", "a"]);
+    });
+});
+
+
+
 /*
 Dedupe Array
 
@@ -16,7 +53,7 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 // Given an empty array
 // When passed to the dedupe function
 // Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+//test.todo("given an empty array, it returns an empty array");
 
 // Given an array with no duplicates
 // When passed to the dedupe function

Sprint-1/implement/max.js

@@ -1,4 +1,24 @@
-function findMax(elements) {
+
+function findMax(arr) {
+    // Requirement 7: Filter out non-numbers and non-numeric strings
+    // Requirement 8: If only non-numbers exist, numericValues will be empty
+    const numericValues = arr
+        .filter((item) => {
+            // Check if it's a number and not NaN
+            if (typeof item === "number" && !isNaN(item)) return true;
+            // Check if it's a numeric string that isn't just whitespace
+            if (typeof item === "string" && item.trim() !== "" && !isNaN(item)) return true;
+            return false;
+        })
+        .map((item) => Number(item));
+
+    // Requirement 2 & 8: Returns -Infinity if no numerical elements are found
+    if (numericValues.length === 0) return -Infinity;
+
+    // Requirement 1, 3, 4, 5, 6: Use Math.max with the spread operator
+    return Math.max(...numericValues);
 }
 
 module.exports = findMax;
+
+

Sprint-1/implement/max.test.js

@@ -1,43 +1,50 @@
-/* Find the maximum element of an array of numbers
-
-In this kata, you will need to implement a function that find the largest numerical element of an array.
-
-E.g. max([30, 50, 10, 40]), target output: 50
-E.g. max(['hey', 10, 'hi', 60, 10]), target output: 60 (sum ignores any non-numerical elements)
-
-You should implement this function in max.js, and add tests for it in this file.
-
-We have set things up already so that this file can see your function from the other file.
-*/
 
 const findMax = require("./max.js");
 
-// Given an empty array
-// When passed to the max function
-// Then it should return -Infinity
-// Delete this test.todo and replace it with a test.
-test.todo("given an empty array, returns -Infinity");
-
-// Given an array with one number
-// When passed to the max function
-// Then it should return that number
-
-// Given an array with both positive and negative numbers
-// When passed to the max function
-// Then it should return the largest number overall
-
-// Given an array with just negative numbers
-// When passed to the max function
-// Then it should return the closest one to zero
-
-// Given an array with decimal numbers
-// When passed to the max function
-// Then it should return the largest decimal number
+describe("findMax()", () => {
+    // Requirement 1
+    test("finds the largest number in an array", () => {
+        expect(findMax([30, 50, 10, 40])).toBe(50);
+    });
+
+    // Requirement 2
+    test("given an empty array, returns -Infinity", () => {
+        expect(findMax([])).toBe(-Infinity);
+    });
+
+    // Requirement 3
+    test("given an array with one number, returns that number", () => {
+        expect(findMax([42])).toBe(42);
+    });
+
+    // Requirement 4
+    test("finds the largest number in a mix of positive and negative numbers", () => {
+        expect(findMax([-10, 5, 0, -2, 20])).toBe(20);
+    });
+
+    // Requirement 5
+    test("given only negative numbers, returns the one closest to zero", () => {
+        expect(findMax([-50, -10, -40])).toBe(-10);
+    });
+
+    // Requirement 6
+    test("finds the largest among decimal numbers", () => {
+        expect(findMax([1.5, 1.55, 1.05])).toBe(1.55);
+    });
+
+    // Requirement 7
+    test("ignores non-numeric values and finds the max", () => {
+        expect(findMax(['hey', 10, 'hi', 60, '10'])).toBe(60);
+    });
+
+    // Requirement 8
+    test("given only non-number values, returns -Infinity", () => {
+        expect(findMax(['apple', 'orange', ' '])).toBe(-Infinity);
+    });
+
+    test("treats numeric strings as numbers", () => {
+        expect(findMax(["10", "20", "5"])).toBe(20);
+    });
+});
 
-// Given an array with non-number values
-// When passed to the max function
-// Then it should return the max and ignore non-numeric values
 
-// Given an array with only non-number values
-// When passed to the max function
-// Then it should return the least surprising value given how it behaves for all other inputs

Sprint-1/implement/sum.js

@@ -1,4 +1,23 @@
-function sum(elements) {
+function sum(arr) {
+    if (!Array.isArray(arr)) return 0;
+
+    return arr.reduce((accumulator, currentValue) => {
+        // We want to skip booleans, null, and empty/whitespace strings 
+        // as Number() would coerce them into 0 or 1.
+        if (typeof currentValue === 'boolean' || currentValue === null ||
+            (typeof currentValue === 'string' && currentValue.trim() === "")) {
+            return accumulator;
+        }
+
+        const numericValue = Number(currentValue);
+
+        // Check if the result is a valid number and not NaN
+        if (!Number.isNaN(numericValue)) {
+            return accumulator + numericValue;
+        }
+
+        return accumulator;
+    }, 0);
 }
 
-module.exports = sum;
+module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -1,36 +1,42 @@
-/* Sum the numbers in an array
-
-In this kata, you will need to implement a function that sums the numerical elements of an array
-
-E.g. sum([10, 20, 30]), target output: 60
-E.g. sum(['hey', 10, 'hi', 60, 10]), target output: 80 (ignore any non-numerical elements)
-*/
 
 const sum = require("./sum.js");
 
-// Acceptance Criteria:
-
-// Given an empty array
-// When passed to the sum function
-// Then it should return 0
-test.todo("given an empty array, returns 0")
-
-// Given an array with just one number
-// When passed to the sum function
-// Then it should return that number
-
-// Given an array containing negative numbers
-// When passed to the sum function
-// Then it should still return the correct total sum
-
-// Given an array with decimal/float numbers
-// When passed to the sum function
-// Then it should return the correct total sum
-
-// Given an array containing non-number values
-// When passed to the sum function
-// Then it should ignore the non-numerical values and return the sum of the numerical elements
+describe("sum()", () => {
+    // Requirement 1 & 6
+    test("should sum numerical elements and ignore non-numerical strings", () => {
+        expect(sum([10, 20, 30])).toBe(60);
+        expect(sum(['hey', 10, 'hi', 60, 10])).toBe(80);
+    });
+
+    // Requirement 2
+    test("given an empty array, it should return 0", () => {
+        expect(sum([])).toBe(0);
+    });
+
+    // Requirement 3
+    test("given an array with one number, it should return that number", () => {
+        expect(sum([42])).toBe(42);
+    });
+
+    // Requirement 4
+    test("given an array with negative numbers, it should return the correct total", () => {
+        expect(sum([10, -5, 20])).toBe(25);
+        expect(sum([-10, -20, 5])).toBe(-25);
+    });
+
+    // Requirement 5
+    test("given an array with decimals, it should return the correct total", () => {
+        // Using toBeCloseTo for float precision safety
+        expect(sum([1.5, 2.5, 1.1])).toBeCloseTo(5.1);
+    });
+
+    // Requirement 7
+    test("given an array with only non-number values, it should return 0", () => {
+        expect(sum(['apple', 'banana', null, undefined])).toBe(0);
+    });
+
+    test("should handle numeric strings correctly", () => {
+        expect(sum(["10", "20", 5])).toBe(35);
+    });
+});
 
-// Given an array with only non-number values
-// When passed to the sum function
-// Then it should return the least surprising value given how it behaves for all other inputs