London | 26-ITP-May | Vito Moratti | Sprint 1 | Module data groups/sprint1

Sprint-1/fix/median.js

@@ -5,10 +5,36 @@
 // 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).
 
+// Fix this implementation
+// Start by running the tests for this function
+// If you're in the Sprint-1 directory, you can run `npm test -- fix` to run the tests in the fix directory
+
+// 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).
+// Fix this implementation
+// Start by running the tests for this function
+// If you're in the Sprint-1 directory, you can run `npm test -- fix` to run the tests in the fix directory
+
+// 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;
+  if (!Array.isArray(list) || list.length < 1) {
+    return null;
+  }
+  const filteredList = list.filter((value) => typeof value === "number");
+  if (filteredList.length < 2) {
+    return null;
+  }
+  const sortedList = filteredList.sort((a, b) => a - b);
+  const evenLength = sortedList.length % 2 === 0;
+  const middleIndex = Math.floor(sortedList.length / 2);
+  if (evenLength) {
+    const evenListCalc =
+      (sortedList[middleIndex] + sortedList[middleIndex - 1]) / 2;
+    return evenListCalc;
+  } else {
+    return sortedList[middleIndex];
+  }
 }
 
 module.exports = calculateMedian;

Sprint-1/implement/dedupe.js

@@ -1 +1,12 @@
-function dedupe() {}
+function dedupe(arr) {
+  let newArr = [];
+  for (let i = 0; i < arr.length; i++) {
+    if (!newArr.includes(arr[i])) {
+      newArr.push(arr[i]);
+    }
+  }
+  return newArr;
+}
+
+console.log(dedupe([1,2,2,2,4]))
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,13 +16,22 @@ 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, it returns a copy of the original array", () => {
+  expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]);
+});
 
 // 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 
 // first occurrence of each element from the original array.
+test("given an array of strings or numbers, it returns a new array with no duplicates removed", () => {
+  expect(dedupe(['a','a','a','b','b','c'])).toEqual(['a','b','c']);
+  expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]);
+}); 

Sprint-1/implement/max.js

@@ -1,4 +1,12 @@
 function findMax(elements) {
+    if (elements.length < 1) {
+        return -Infinity;
+    } else {
+        const filteredList = elements.filter((value) => typeof value === "number");
+        return Math.max( ...filteredList)}
+
 }
 
 module.exports = findMax;
+
+//console.log(findMax([30, 50, 10, 40])); // 50

Sprint-1/implement/max.test.js

@@ -16,28 +16,59 @@ 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
+describe("findMax", () => {
+  [{ input: [3], expected: 3 }].forEach(({ input, expected }) =>
+    it(`returns the only number in the array for [${input}]`, () =>
+      expect(findMax(input)).toEqual(expected))
+  );
+});
 
 // 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, returns the largest", () => {
+  expect(findMax([1, -2, 3, -4, 5])).toEqual(5);
+});
 
 // 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, returns closest to zero", () => {
+  expect(findMax([-1, -2, -3, -4])).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, returns largest decimal number", () => {
+  expect(findMax([1.5, 1.6, 1.7, 1.8])).toEqual(1.8);
+  expect(findMax([-1.5, -1.6, -1.7, -1.8])).toEqual(-1.5);
+});
 
 // 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, returns the max and ignores non-numeric values", () => {
+  expect(findMax([1, 2, "3", null, undefined, 4])).toEqual(4);
+  expect(findMax(["apple", 1, 2, 3, "banana", 4])).toEqual(4);
+  expect(findMax([1, "2", 3, "4", 5])).toEqual(5);
+  expect(findMax([1, "apple", 2, null, 3, undefined, 4])).toEqual(4);
+  expect(findMax([3, "apple", 1, null, 2, undefined, 4])).toEqual(4);
+  expect(findMax(["banana", 5, 3, "apple", 1, 4, 2])).toEqual(5);
+});
 
 // 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, returns -Infinity", () => {
+  expect(findMax(["apple", null, undefined])).toEqual(-Infinity);
+  expect(findMax([null, undefined])).toEqual(-Infinity);
+  expect(findMax(["apple", "banana"])).toEqual(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,10 @@
 function sum(elements) {
+    let innit = 0;
+    const filteredList = elements.filter((value) => typeof value === "number");
+    for (let i = 0; i < filteredList.length; i++) {
+        innit += filteredList[i];
+    }
+return innit; 
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,44 @@ 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 returns that number", () => {
+  expect(sum([2])).toEqual(2);
+});
 
 // 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, returns the correct total sum", () => {
+  expect(sum([-1, -2, -3])).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, returns the correct total sum", () => {
+  expect(sum([1.5, 2.5, 3.5])).toEqual(7.5);
+  expect(sum([-1.5, -2.5, -3.5])).toEqual(-7.5);
+});
 
 // 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, ignores the non-numerical values and returns the sum of the numerical elements", () => {
+  expect(sum([1, 2, "3", null, undefined, 4])).toEqual(7);
+  expect(sum(["apple", 1, 2, 3, "banana", 4])).toEqual(10);
+  expect(sum([1, "2", 3, "4", 5])).toEqual(9);
+});
 
 // 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, returns 0", () => {
+  expect(sum(["apple", "banana", null, undefined])).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 i of list) {
+    if (i === target) {
       return true;
     }
   }