added solutions to max.js

Author: Alex Jamshidi

Sprint-1/implement/max.js

@@ -1,4 +1,7 @@
-function findMax(elements) {
+function findMax(list) {
+    const numbers = list.filter(n => Number.isFinite(n));
+    if (numbers.length == 0) { return "-Infinity"}
+    else {return Math.max(...numbers)};
 }
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -12,32 +12,72 @@ We have set things up already so that this file can see your function from the o
 
 const findMax = require("./max.js");
 
+describe("calculateMedian", () => {
 // 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");
+
+  it("empty array returns -Infinity", () => {
+    const list = [];
+    expect(findMax(list)).toEqual("-Infinity");
+  });
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
 
+  it("array with one number returns that number", () => {
+    const list = [2];
+    expect(findMax(list)).toEqual(2);
+  });
+
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
 
+  it("array with +ve and -ve numbers, returns largest number overall", () => {
+    const list = [10, -15];
+    expect(findMax(list)).toEqual(10);
+  });
+
+
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
 
+  it("array -ve numbers, returns closest to zero", () => {
+    const list = [-1, -2, -3, -15];
+    expect(findMax(list)).toEqual(-1);
+  });
+
+
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
 
+  it("array with decimal numbers should return largest decimal number", () => {
+    const list = [1.9, 2.8999, 3.1];
+    expect(findMax(list)).toEqual(3.1);
+  });
+
+
 // Given an array with non-number values
 // When passed to the max function
 // Then it should return the max and ignore non-numeric values
 
+  it("array with non-number values, returns the max and ignore non-numeric values", () => {
+    const list = [1, "a", 2, "b", 3, "c"];
+    expect(findMax(list)).toEqual(3);
+  });
+
+
 // 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
+
+  it("array with only non-number values, return the least surprising value given how it behaves for all other inputs", () => {
+    const list = ["a", "b", "c"];
+    expect(findMax(list)).toEqual("-Infinity");
+  });
+});