Save-only warning added

__tests__/saveOnly.test.ts

@@ -91,3 +91,31 @@ test("save with valid inputs uploads a cache", async () => {
 
     expect(failedMock).toHaveBeenCalledTimes(0);
 });
+
+test("save failing logs the warning message", async () => {
+    const warningMock = jest.spyOn(core, "warning");
+
+    const primaryKey = "Linux-node-bb828da54c148048dd17899ba9fda624811cfb43";
+
+    const inputPath = "node_modules";
+    testUtils.setInput(Inputs.Key, primaryKey);
+    testUtils.setInput(Inputs.Path, inputPath);
+    testUtils.setInput(Inputs.UploadChunkSize, "4000000");
+
+    const cacheId = -1;
+    const saveCacheMock = jest
+        .spyOn(cache, "saveCache")
+        .mockImplementationOnce(() => {
+            return Promise.resolve(cacheId);
+        });
+
+    await run();
+
+    expect(saveCacheMock).toHaveBeenCalledTimes(1);
+    expect(saveCacheMock).toHaveBeenCalledWith([inputPath], primaryKey, {
+        uploadChunkSize: 4000000
+    });
+
+    expect(warningMock).toHaveBeenCalledTimes(1);
+    expect(warningMock).toHaveBeenCalledWith("Cache save failed.");
+});