Updated the test system

test/yesNo.test.js

@@ -0,0 +1,42 @@
+const expect = require('expect');
+const {yesNo} = require('./_30s.js');
+
+test('yesNo is a Function', () => {
+  expect(yesNo).toBeInstanceOf(Function);
+});
+test('yesNo(Y) returns true', () => {
+  expect(yesNo('Y')).toBeTruthy();
+});
+test('yesNo(yes) returns true', () => {
+  expect(yesNo('yes')).toBeTruthy();
+});
+test('yesNo(foo, true) returns true', () => {
+  expect(yesNo('foo', true)).toBeTruthy();
+});
+test('yesNo(No) returns false', () => {
+  expect(yesNo('No')).toBeFalsy();
+});
+test('yesNo() returns false', () => {
+  expect(yesNo()).toBeFalsy();
+});
+test('yesNo(null) returns false', () => {
+  expect(yesNo(null)).toBeFalsy();
+});
+test('yesNo(undefined) returns false', () => {
+  expect(yesNo(undefined)).toBeFalsy();
+});
+test('yesNo([123, null]) returns false', () => {
+  expect(yesNo([123, null])).toBeFalsy();
+});
+test('yesNo([Yes, No]) returns false', () => {
+  expect(yesNo(['Yes', 'No'])).toBeFalsy();
+});
+test('yesNo({ 2: Yes }) returns false', () => {
+  expect(yesNo({ 2: 'Yes' })).toBeFalsy();
+});
+test('yesNo([Yes, No], true) returns true', () => {
+  expect(yesNo(['Yes', 'No'], true)).toBeTruthy();
+});
+test('yesNo({ 2: Yes }, true) returns true', () => {
+  expect(yesNo({ 2: 'Yes' }, true)).toBeTruthy();
+});