History utility tests

Author: Travis Lawrence

src/utilities/__tests__/history.test.js

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+/*global chrome*/
+import History from "../history";
+
+const mockResponse = {
+  date: "2007-09-05",
+  explanation: "On September 1, Aurigid meteors filled the sky...",
+  hdurl: "https://apod.nasa.gov/apod/image/0709/AurigidVaubaillon.jpg",
+  media_type: "image",
+  service_version: "v1",
+  title: "Aurigids from 47,000 Feet",
+  url: "https://apod.nasa.gov/apod/image/0709/AurigidVaubaillon720.jpg"
+};
+
+const mockResponse2 = { ...mockResponse, date: "2015-10-12" };
+
+describe("History Helper Utility", () => {
+  let history;
+
+  beforeEach(() => {
+    history = new History();
+  });
+
+  it("creates a new object", () => {
+    expect(history.responses.length).toBe(0);
+    expect(history.currentIdx).toBe(0);
+  });
+
+  it("adds response to history", () => {
+    history.add(mockResponse);
+    expect(history.responses.length).toBe(1);
+    expect(history.currentIdx).toBe(0);
+  });
+
+  it("adds multiple responses to history", () => {
+    history.add(mockResponse);
+    history.add(mockResponse2);
+    expect(history.responses.length).toBe(2);
+    expect(history.currentIdx).toBe(1);
+  });
+
+  it("will not add existing  response to history", () => {
+    history.add(mockResponse);
+    history.add(mockResponse);
+    expect(history.responses.length).toBe(1);
+    expect(history.currentIdx).toBe(0);
+  });
+
+  it("gets previous date", () => {
+    history.add(mockResponse);
+    history.add(mockResponse2);
+
+    const response = history.getPreviousDate();
+    expect(response).toMatchObject(history.responses[0]);
+  });
+
+  it("no previous dates responds false", () => {
+    history.add(mockResponse);
+    history.add(mockResponse2);
+
+    history.getPreviousDate();
+    const response = history.getPreviousDate();
+    expect(response).toBe(false);
+  });
+
+  it("gets next date", () => {
+    history.add(mockResponse);
+    history.add(mockResponse2);
+
+    history.getPreviousDate();
+    const response = history.getNextDate();
+    expect(response).toMatchObject(history.responses[1]);
+  });
+
+  it("no next date responds false", () => {
+    history.add(mockResponse);
+    history.add(mockResponse2);
+
+    const response = history.getNextDate();
+    expect(response).toBe(false);
+  });
+});