diff --git a/__tests__/stateProvider.test.ts b/__tests__/stateProvider.test.ts
new file mode 100644
index 0000000..4c588ac
--- /dev/null
+++ b/__tests__/stateProvider.test.ts
@@ -0,0 +1,71 @@
+import * as core from "@actions/core";
+
+import { Events, RefKey, State } from "../src/constants";
+import {
+    IStateProvider,
+    NullStateProvider,
+    StateProvider
+} from "../src/stateProvider";
+
+jest.mock("@actions/core");
+
+beforeAll(() => {
+    jest.spyOn(core, "getInput").mockImplementation((name, options) => {
+        return jest.requireActual("@actions/core").getInput(name, options);
+    });
+
+    jest.spyOn(core, "setOutput").mockImplementation((key, value) => {
+        return jest.requireActual("@actions/core").setOutput(key, value);
+    });
+});
+
+afterEach(() => {
+    delete process.env[Events.Key];
+    delete process.env[RefKey];
+});
+
+test("StateProvider saves states", async () => {
+    const getStateMock = jest
+        .spyOn(core, "getState")
+        .mockImplementation(name =>
+            jest.requireActual("@actions/core").getState(name)
+        );
+    const saveStateMock = jest
+        .spyOn(core, "saveState")
+        .mockImplementation((key, value) => {
+            return jest.requireActual("@actions/core").saveState(key, value);
+        });
+
+    const cacheMatchedKey = "node-cache";
+
+    const stateProvider: IStateProvider = new StateProvider();
+    stateProvider.setState("stateKey", "stateValue");
+    stateProvider.setState(State.CacheMatchedKey, cacheMatchedKey);
+    stateProvider.getState("stateKey");
+    stateProvider.getCacheState();
+
+    expect(getStateMock).toHaveBeenCalledTimes(2);
+    expect(saveStateMock).toHaveBeenCalledTimes(2);
+});
+
+test("NullStateProvider saves outputs", async () => {
+    const getStateMock = jest
+        .spyOn(core, "getState")
+        .mockImplementation(name =>
+            jest.requireActual("@actions/core").getState(name)
+        );
+    const setOutputMock = jest
+        .spyOn(core, "setOutput")
+        .mockImplementation((key, value) => {
+            return jest.requireActual("@actions/core").setOutput(key, value);
+        });
+    const cacheMatchedKey = "node-cache";
+    const nullStateProvider: IStateProvider = new NullStateProvider();
+    nullStateProvider.setState("outputKey", "outputValue");
+    nullStateProvider.setState(State.CacheMatchedKey, cacheMatchedKey);
+    nullStateProvider.getState("outputKey");
+    nullStateProvider.getCacheState();
+
+    expect(getStateMock).toHaveBeenCalledTimes(0);
+    expect(setOutputMock).toHaveBeenCalledTimes(2);
+});