Max function tests to cover additional cases including decimals and non-numeric values

Author: ashaahmed7

Sprint-1/implement/max.test.js

@@ -16,28 +16,94 @@ 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");
 
-// Given an array with one number
-// When passed to the max function
-// Then it should return that number
+describe("max()", () => {
+  it("returns -Infinity for empty array", () =>
+    expect(findMax([])).toBe(-Infinity));
 
-// 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 one number
+  // When passed to the max function
+  // Then it should return that number
 
-// Given an array with just negative numbers
-// When passed to the max function
-// Then it should return the closest one to zero
+  [
+    { input: [43], expected: 43 },
+    { input: [342], expected: 342 },
+    { input: [65455453], expected: 65455453 },
+  ].forEach(({ input, expected }) =>
+    it("returns the only number in array with one number", () =>
+      expect(findMax(input)).toBe(expected))
+  );
 
-// Given an array with decimal numbers
-// When passed to the max function
-// Then it should return the largest decimal 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 non-number values
-// When passed to the max function
-// Then it should return the max and ignore non-numeric values
+  [
+    { input: [43, -4], expected: 43 },
+    { input: [342, -45, -768, 23], expected: 342 },
+    { input: [65455453, -54666, -4566, 6565], expected: 65455453 },
+  ].forEach(({ input, expected }) =>
+    it("returns the largest number in array containing negative numbers", () =>
+      expect(findMax(input)).toBe(expected))
+  );
 
-// 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
+  // Given an array with just negative numbers
+  // When passed to the max function
+  // Then it should return the closest one to zero
+
+  [
+    { input: [-43, -4], expected: -4 },
+    { input: [-342, -45, -768, -23], expected: -23 },
+    { input: [-65455453, -54666, -4566, -6565], expected: -4566 },
+  ].forEach(({ input, expected }) =>
+    it("returns closes number to zero in an array with only negative numbers", () =>
+      expect(findMax(input)).toBe(expected))
+  );
+
+  // Given an array with decimal numbers
+  // When passed to the max function
+  // Then it should return the largest decimal number
+
+  [
+    { input: [43.32, -4.1], expected: 43.32 },
+    { input: [342.54, -45.12, -768.76, 23.99], expected: 342.54 },
+    {
+      input: [65455453.4533, -54666.222, -4566.322, 6565.43],
+      expected: 65455453.4533,
+    },
+  ].forEach(({ input, expected }) =>
+    it("returns the largest decimal number in an array with numbers", () =>
+      expect(findMax(input)).toBe(expected))
+  );
+
+  // Given an array with non-number values
+  // When passed to the max function
+  // Then it should return the max and ignore non-numeric values
+
+  [
+    { input: [0, NaN, 1], expected: 1 },
+    { input: [1, 2, "3", null, undefined, NaN, 4], expected: 4 },
+    { input: ["apple", 1, 2, 34, "banana", 4], expected: 34 },
+    { input: [1, "2", 3, "4", 5], expected: 5 },
+    { input: [1, "apple", 2, null, 3, undefined, 4], expected: 4 },
+    { input: [3, "apple", 1, null, 2, undefined, 4, 54], expected: 54 },
+    { input: ["banana", 5, 3, "apple", 1, 4, 2], expected: 5 },
+  ].forEach(({ input, expected }) =>
+    it("returns max of numbers in an array containing non-numeric values", () =>
+      expect(findMax(input)).toEqual(expected))
+  );
+
+  // 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
+
+  [
+    ["not an array", "3", null, undefined],
+    ["apple", "banana"],
+    ["apple", null, undefined],
+    ["banana", {}],
+  ].forEach((input) =>
+    it("returns -Infinity in array with only non-numeric values", () =>
+      expect(findMax(input)).toBe(-Infinity))
+  );
+});