Massive refactor (#165)

src/utilities/dockerUtils.test.ts

@@ -0,0 +1,15 @@
+import * as io from "@actions/io";
+import { checkDockerPath } from "./dockerUtils";
+
+describe("docker utilities", () => {
+  it("checks if docker is installed", async () => {
+    // docker installed
+    const path = "path";
+    jest.spyOn(io, "which").mockImplementationOnce(async () => path);
+    expect(() => checkDockerPath()).not.toThrow();
+
+    // docker not installed
+    jest.spyOn(io, "which").mockImplementationOnce(async () => undefined);
+    await expect(() => checkDockerPath()).rejects.toThrow();
+  });
+});