Merge pull request #111 from huwshimi/handle-no-versions

Be defensive about returned version data

api/tests/test-versions.ts

@@ -1,34 +1,85 @@
-import { cachedAPIResponse, jujuUpdateAvailable } from "../versions";
+import {
+  cachedAPIResponse,
+  jujuUpdateAvailable,
+  dashboardUpdateAvailable,
+} from "../versions";
 
 describe("versions", () => {
-  // mock fetch: https://juju.is/latest.json
-  const mockFetch = jest.fn();
-  mockFetch.mockReturnValue({
-    json: () => ({
-      dashboard: "2.8.1",
-      juju: ["2.8.1", "2.8.0", "2.7.9"],
-    }),
-  });
-  global.fetch = mockFetch;
+  let fetchSpy: jest.SpyInstance;
+
+  beforeAll(() => {
+    fetchSpy = jest.spyOn(global, "fetch");
+  });
+
+  beforeEach(() => {
+    // invalidate the cache
+    cachedAPIResponse?.fetchedAt.setTime(0);
+    // mock fetch: https://juju.is/latest.json
+    fetchSpy.mockImplementation(
+      jest.fn(() =>
+        Promise.resolve({
+          json: () => ({
+            dashboard: "2.8.1",
+            juju: ["2.8.1", "2.8.0", "2.7.9"],
+          }),
+        })
+      ) as jest.Mock
+    );
+  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+  });
+
+  afterAll(() => {
+    jest.restoreAllMocks();
+  });
+
   it("should return true if the Juju controller version is old", async () => {
     expect(await jujuUpdateAvailable("2.7.8")).toBe(true);
   });
+
   it("should return false if the Juju controller version is new", async () => {
     expect(await jujuUpdateAvailable("2.8.1")).toBe(false);
   });
+
   it("should return true if the Juju dashboard version is old", async () => {
-    expect(await jujuUpdateAvailable("2.2.0")).toBe(true);
+    expect(await dashboardUpdateAvailable("2.2.0")).toBe(true);
   });
+
   it("should return false if the Juju dashboard version is new", async () => {
-    expect(await jujuUpdateAvailable("2.8.1")).toBe(false);
+    expect(await dashboardUpdateAvailable("2.8.1")).toBe(false);
   });
+
+  it("handles no juju version response", async () => {
+    fetchSpy.mockImplementation(
+      jest.fn(() =>
+        Promise.resolve({
+          json: () => ({}),
+        })
+      ) as jest.Mock
+    );
+    expect(await jujuUpdateAvailable("2.8.1")).toBeNull();
+  });
+
+  it("handles no dashboard version response", async () => {
+    fetchSpy.mockImplementation(
+      jest.fn(() =>
+        Promise.resolve({
+          json: () => ({}),
+        })
+      ) as jest.Mock
+    );
+    expect(await dashboardUpdateAvailable("2.2.0")).toBeNull();
+  });
+
   it("should use TTL to cache the response", async () => {
     await jujuUpdateAvailable("2.7.8");
     await jujuUpdateAvailable("2.7.8");
-    expect(mockFetch).toHaveBeenCalledTimes(1);
+    expect(fetchSpy).toHaveBeenCalledTimes(1);
     // invalidate the cache
     cachedAPIResponse?.fetchedAt.setTime(0);
     await jujuUpdateAvailable("2.7.8");
-    expect(mockFetch).toHaveBeenCalledTimes(2);
+    expect(fetchSpy).toHaveBeenCalledTimes(2);
   });
 });

api/versions.ts

@@ -17,7 +17,7 @@ const versionGreaterThan = (v1: string, v2: string): boolean => {
 };
 
 const sortVersions = (versions: string[]): string[] =>
-  versions.sort((v1, v2) => {
+  versions?.sort((v1, v2) => {
     if (versionGreaterThan(v1, v2)) {
       return -1;
     } else if (versionGreaterThan(v2, v1)) {
@@ -49,7 +49,10 @@ const fetchVersions = async () => {
     return cachedAPIResponse.data;
   cachedAPIResponse = null;
   const response = await fetch("https://juju.is/latest.json");
-  const data = await response.json();
+  const data: APIPayload | undefined = await response?.json();
+  if (!data) {
+    return null;
+  }
   cachedAPIResponse = {
     data: { ...data, juju: sortVersions(data.juju) },
     fetchedAt: new Date(),
@@ -64,7 +67,10 @@ const fetchVersions = async () => {
  * @returns
  */
 export const jujuUpdateAvailable = async (jujuVersion: string) => {
-  const jujuVersions = (await fetchVersions()).juju;
+  const jujuVersions = (await fetchVersions())?.juju;
+  if (!jujuVersions) {
+    return null;
+  }
   const latestAvailableVersion = jujuVersions.slice(-1)[0];
   return versionGreaterThan(latestAvailableVersion, jujuVersion);
 };
@@ -76,6 +82,9 @@ export const jujuUpdateAvailable = async (jujuVersion: string) => {
  * @returns
  */
 export const dashboardUpdateAvailable = async (dashboardVersion: string) => {
-  const latestDashboardVersion = (await fetchVersions()).dashboard;
+  const latestDashboardVersion = (await fetchVersions())?.dashboard;
+  if (!latestDashboardVersion) {
+    return null;
+  }
   return versionGreaterThan(latestDashboardVersion, dashboardVersion);
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@canonical/jujulib",
-  "version": "3.2.0",
+  "version": "3.2.1",
   "description": "Juju API client",
   "main": "dist/api/client.js",
   "types": "dist/api/client.d.ts",