London | May-26 | Liridona Shehu | Sprint 1 | Module-Data-Groups

Sprint-1/fix/median.js

@@ -6,9 +6,34 @@
 // 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 if is an array
+  if (!Array.isArray(list)) {
+    return null;
+  }
+  //Filter numeric values
+  const filteredNumericValues = list.filter(
+    (item) => typeof item === "number" && Number.isFinite(item)
+  );
+  if (filteredNumericValues.length === 0) {
+    return null;
+  }
+
+  // Sort filtered numeric values
+  const sortedNumericValues = filteredNumericValues.toSorted((a, b) => a - b);
+  let middleIndex = Math.floor(sortedNumericValues.length / 2);
+  let medianValue;
+  // ODD length
+  if (sortedNumericValues.length % 2 !== 0) {
+    medianValue = sortedNumericValues.slice(middleIndex, middleIndex + 1);
+    return medianValue[0];
+  }
+
+  // EVEN length
+  else
+    return (medianValue =
+      (sortedNumericValues[middleIndex - 1] +
+        sortedNumericValues[middleIndex]) /
+      2);
 }
 
 module.exports = calculateMedian;

Sprint-1/implement/dedupe.js

@@ -1 +1,5 @@
-function dedupe() {}
+function dedupe(elements) {
+  return Array.from(new Set(elements));
+}
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,13 +16,21 @@ E.g. dedupe([1, 2, 1]) returns [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("given an empty array, it returns an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("Given an array with no duplicates should return a copy of the original array", () => {
+  expect(dedupe([1, 2, 3, 4, 5, 6])).toEqual([1, 2, 3, 4, 5, 6]);
+});
 
 // Given an array of strings or numbers
 // When passed to the dedupe function
-// Then it should return a new array with duplicates removed while preserving the 
+// Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
+test("Given an array of strings or numbers should return a new array with duplicates removed while preserving the first occurrence from the original array.", () => {
+  expect(dedupe([1, 2, 1])).toEqual([1, 2]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,11 @@
 function findMax(elements) {
+  if (elements.length === 0) {
+    return -Infinity;
+  }
+  let filteredNumericValues = elements.filter((item) => Number.isFinite(item));
+  console.log(filteredNumericValues);
+
+  return Math.max(...filteredNumericValues);
 }
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -16,28 +16,48 @@ const findMax = require("./max.js");
 // 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");
+test("given an empty array, returns -Infinity", () => {
+  expect(findMax([])).toEqual(-Infinity);
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
+test("Given an array with one number should return that number", () => {
+  expect(findMax([1])).toEqual(1);
+});
 
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
+test("Given an array with both positive and negative numbers should return the largest number overall", () => {
+  expect(findMax([-1, 2, -3, 4, -5])).toEqual(4);
+});
 
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
+test("Given an array with just negative numbers should return the closest one to zero", () => {
+  expect(findMax([-1, -2, -3, -4, -5])).toEqual(-1);
+});
 
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
+test("Given an array with decimal numbers should return the largest decimal number", () => {
+  expect(findMax([1.5, 2.5, 3.5, 4.5])).toEqual(4.5);
+});
 
 // Given an array with non-number values
 // When passed to the max function
 // Then it should return the max and ignore non-numeric values
+test(" Given an array with non-number values should return the max and ignore non-numeric values", () => {
+  expect(findMax([1, "hello", 2, undefined, null])).toEqual(2);
+});
 
 // 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
+test("Given an array with only non-number values should return the least surprising value given how it behaves for all other inputs", () => {
+  expect(findMax(["hello", undefined, null, NaN])).toEqual(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,10 @@
 function sum(elements) {
+  let filteredNumericValues = elements.filter((item) => Number.isFinite(item));
+  let sumOfElements = 0;
+  for (let item of filteredNumericValues) {
+    sumOfElements += item;
+  }
+  return sumOfElements;
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,39 @@ const sum = require("./sum.js");
 // Given an empty array
 // When passed to the sum function
 // Then it should return 0
-test.todo("given an empty array, returns 0")
+test("given an empty array, returns 0", () => {
+  expect(sum([])).toEqual(0);
+});
 
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
-
+test("Given an array with just one number should return that number", () => {
+  expect(sum([1])).toEqual(1);
+});
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
+test("Given an array containing negative numbers should return the total sum", () => {
+  expect(sum([-1, 2, -3, -4])).toEqual(-6);
+});
 
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
-
+test("Given an array with decimal/float numbers should return sum", () => {
+  expect(sum([1.5, 2.5, 3.5, 4.5])).toEqual(12);
+});
 // 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
+test("Given an array containing non-number values should ignore non-numerical values and return the sum", () => {
+  expect(sum([1, "hello", null, undefined, NaN, 2, 3])).toEqual(6);
+});
 
 // 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
+test("Given an array with only non-number values should return 0", () => {
+  expect(sum(["hello", null, undefined, NaN])).toEqual(0);
+});

Sprint-1/refactor/includes.js

@@ -1,9 +1,8 @@
 // Refactor the implementation of includes to use a for...of loop
 
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
-    if (element === target) {
+  for (let item of list) {
+    if (item === target) {
       return true;
     }
   }