TS: Add an Approval base test similar to Java-Approvals and CS-xunit-verify using Jest Snapshot.

TypeScript/test/jest/approvals.spec.ts

@@ -0,0 +1,54 @@
+import { Item, GildedRose } from '@/gilded-rose';
+
+/**
+ * This unit test uses [Jest Snapshot](https://goo.gl/fbAQLP).
+ * 
+ * There are two test cases here with different styles:
+ * <li>"foo" is more similar to the unit test from the 'Java' version
+ * <li>"thirtyDays" is more similar to the TextTest from the 'Java' version
+ *
+ * I suggest choosing one style to develop and deleting the other.
+ */
+
+describe('Gilded Rose Approval', () => {
+
+  let gameConsoleOutput: string;
+  let originalConsoleLog: (message: any) => void;
+  let originalProcessArgv: string[]
+
+  function gameConsoleLog(msg: string) {
+    if (msg) {
+      gameConsoleOutput += msg;
+    }
+    gameConsoleOutput += "\n";
+  }
+
+  beforeEach(() => {
+    // prepare capturing console.log to our own gameConsoleLog.
+    gameConsoleOutput = "";
+    originalConsoleLog = console.log;
+    console.log = gameConsoleLog;
+    originalProcessArgv = process.argv;
+  });
+
+  afterEach(() => {
+    // reset original console.log
+    console.log = originalConsoleLog;
+    process.argv = originalProcessArgv;
+  });
+
+  it('should foo', () => {
+    const gildedRose = new GildedRose([new Item('foo', 0, 0)]);
+    const items = gildedRose.updateQuality();
+  
+    expect(items).toMatchSnapshot();
+  });
+
+  it('should thirtyDays', () => {
+    process.argv = ["<node>", "<script", "30"];
+    require('../golden-master-text-test.ts');
+       
+    expect(gameConsoleOutput).toMatchSnapshot();
+  });
+
+});