Add some basic unit tests for the following files: (#1050)

* Add some basic unit tests for cluster, kube-auth-proxy, and kubeconfig-manager

- src/main/cluster.ts
- src/main/kube-auth-proxy.ts
- src/main/kubeconfig-manager.ts

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/main/__test__/kubeconfig-manager.test.ts

@@ -0,0 +1,112 @@
+const logger = {
+  silly: jest.fn(),
+  debug: jest.fn(),
+  log: jest.fn(),
+  info: jest.fn(),
+  error: jest.fn(),
+  crit: jest.fn(),
+};
+
+jest.mock("winston", () => ({
+  format: {
+    colorize: jest.fn(),
+    combine: jest.fn(),
+    simple: jest.fn(),
+    label: jest.fn(),
+    timestamp: jest.fn(),
+    printf: jest.fn()
+  },
+  createLogger: jest.fn().mockReturnValue(logger),
+  transports: {
+    Console: jest.fn(),
+    File: jest.fn(),
+  }
+}))
+
+import { KubeconfigManager } from "../kubeconfig-manager"
+import mockFs from "mock-fs"
+import { Cluster } from "../cluster";
+import { workspaceStore } from "../../common/workspace-store";
+import { ContextHandler } from "../context-handler";
+import { getFreePort } from "../port";
+import fse from "fs-extra"
+import { loadYaml } from "@kubernetes/client-node";
+import { Console } from "console";
+
+console = new Console(process.stdout, process.stderr) // fix mockFS
+
+describe("kubeconfig manager tests", () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  beforeEach(() => {
+    const mockOpts = {
+      "minikube-config.yml": JSON.stringify({
+        apiVersion: "v1",
+        clusters: [{
+          name: "minikube",
+          cluster: {
+            server: "https://192.168.64.3:8443",
+          },
+        }],
+        contexts: [{
+          context: {
+            cluster: "minikube",
+            user: "minikube",
+          },
+          name: "minikube",
+        }],
+        users: [{
+          name: "minikube",
+        }],
+        kind: "Config",
+        preferences: {},
+      })
+    }
+    mockFs(mockOpts)
+  })
+
+  afterEach(() => {
+    mockFs.restore()
+  })
+
+  it("should create 'temp' kube config with proxy", async () => {
+    const cluster = new Cluster({
+      id: "foo",
+      contextName: "minikube",
+      kubeConfigPath: "minikube-config.yml",
+      workspace: workspaceStore.currentWorkspaceId
+    })
+    const contextHandler = new ContextHandler(cluster)
+    const port = await getFreePort()
+    const kubeConfManager = await KubeconfigManager.create(cluster, contextHandler, port)
+
+    expect(logger.error).not.toBeCalled()
+    expect(kubeConfManager.getPath()).toBe("tmp/kubeconfig-foo")
+    const file = await fse.readFile(kubeConfManager.getPath())
+    const yml = loadYaml<any>(file.toString())
+    expect(yml["current-context"]).toBe("minikube")
+    expect(yml["clusters"][0]["cluster"]["server"]).toBe(`http://127.0.0.1:${port}/foo`)
+    expect(yml["users"][0]["name"]).toBe("proxy")
+  })
+
+  it("should remove 'temp' kube config on unlink and remove reference from inside class", async () => {
+    const cluster = new Cluster({
+      id: "foo",
+      contextName: "minikube",
+      kubeConfigPath: "minikube-config.yml",
+      workspace: workspaceStore.currentWorkspaceId
+    })
+    const contextHandler = new ContextHandler(cluster)
+    const port = await getFreePort()
+    const kubeConfManager = await KubeconfigManager.create(cluster, contextHandler, port)
+
+    const configPath = kubeConfManager.getPath()
+    expect(await fse.pathExists(configPath)).toBe(true)
+    await kubeConfManager.unlink()
+    expect(await fse.pathExists(configPath)).toBe(false)
+    await kubeConfManager.unlink() // doesn't throw
+    expect(kubeConfManager.getPath()).toBeUndefined()
+  })
+})