add unit tests

Author: jschwarz2030

src/utils/constructChangesetUrl.js

@@ -1,6 +1,7 @@
 export const constructChangesetUrl = (task) => {
   if (
     process.env.REACT_APP_CHANGESET_URL === "enabled" &&
+    task?.parent?.id &&
     task.parent.changesetUrl
   ) {
     return ` ${window.location.origin}/browse/challenges/${task.parent.id}`;

src/utils/constructChangesetUrl.test.js

@@ -0,0 +1,36 @@
+import { constructChangesetUrl } from "./constructChangesetUrl";
+
+describe("constructChangesetUrl", () => {
+  const cachedEnv = process.env;
+
+  beforeEach(() => {
+    jest.resetModules();
+    process.env = { ...cachedEnv, REACT_APP_CHANGESET_URL: "enabled" };
+  });
+
+  afterAll(() => {
+    process.env = cachedEnv;
+  });
+
+  it("returns empty string if no task is provided", () => {
+    expect(constructChangesetUrl()).toBe("");
+  });
+
+  it("returns empty string if env variabled is disabled", () => {
+    process.env.REACT_APP_CHANGESET_URL = "disabled";
+    const task = { parent: { changesetUrl: true, id: 1 } };
+    expect(constructChangesetUrl(task)).toBe("");
+  });
+
+  it("returns empty string changesetUrl is false", () => {
+    const task = { parent: { changesetUrl: false, id: 1 } };
+    expect(constructChangesetUrl(task)).toBe("");
+  });
+
+  it("returns correct url if changesetUrl is true", () => {
+    const task = { parent: { changesetUrl: true, id: 1 } };
+    expect(constructChangesetUrl(task)).toBe(
+      " http://localhost/browse/challenges/1"
+    );
+  });
+});