test: test decoder chain

src/__tests__/decoding.spec.ts

@@ -0,0 +1,119 @@
+import { empty, of, Task, fail } from "../Task/Task"
+
+interface Command {
+  commandId?: string
+}
+
+const CMD: Command = { commandId: "1234" }
+
+const getCommandSuccess = (): Task<unknown, Command | undefined> =>
+  of<Command>(CMD)
+
+const getCommandFailure = (): Task<unknown, Command | undefined> => empty()
+
+const getCommandNoCommand = (): Task<unknown, Command | undefined> =>
+  of<Command>({ commandId: undefined })
+
+const rejectFailures = (result?: Command): Task<undefined, Command> =>
+  result && result.commandId ? of(result) : fail(undefined)
+
+enum Status {
+  CREATED,
+  COMPLETED,
+}
+
+interface Result {
+  status: Status
+  cmd: Command
+}
+
+const executeCommandCreated = (
+  cmd: Command,
+): Task<unknown, Result | undefined> =>
+  of<Result>({ cmd, status: Status.CREATED })
+
+const executeCommandCompleted = (
+  cmd: Command,
+): Task<unknown, Result | undefined> =>
+  of<Result>({ cmd, status: Status.COMPLETED })
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const executeCommandFail = (_cmd: Command): Task<unknown, Result | undefined> =>
+  fail(undefined)
+
+const keepCreated = (result?: Result): Task<undefined, Result> =>
+  result && result.status === Status.CREATED ? of(result) : fail(undefined)
+
+describe("decoding", () => {
+  test("success", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandSuccess().chain(rejectFailures).fork(reject, resolve)
+
+    expect(reject).not.toBeCalled()
+    expect(resolve).toBeCalledWith(CMD)
+  })
+
+  test("failure", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandFailure().chain(rejectFailures).fork(reject, resolve)
+
+    expect(reject).toBeCalledWith(undefined)
+    expect(resolve).not.toBeCalled()
+  })
+
+  test("no command", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandNoCommand().chain(rejectFailures).fork(reject, resolve)
+
+    expect(reject).toBeCalledWith(undefined)
+    expect(resolve).not.toBeCalled()
+  })
+
+  test("success created", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandSuccess()
+      .chain(rejectFailures)
+      .chain(executeCommandCreated)
+      .chain(keepCreated)
+      .fork(reject, resolve)
+
+    expect(reject).not.toBeCalled()
+    expect(resolve).toBeCalledWith({ cmd: CMD, status: Status.CREATED })
+  })
+
+  test("success completed", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandSuccess()
+      .chain(rejectFailures)
+      .chain(executeCommandCompleted)
+      .chain(keepCreated)
+      .fork(reject, resolve)
+
+    expect(reject).toBeCalledWith(undefined)
+    expect(resolve).not.toBeCalled()
+  })
+
+  test("success then failed", () => {
+    const resolve = jest.fn()
+    const reject = jest.fn()
+
+    getCommandSuccess()
+      .chain(rejectFailures)
+      .chain(executeCommandFail)
+      .chain(keepCreated)
+      .fork(reject, resolve)
+
+    expect(reject).toBeCalledWith(undefined)
+    expect(resolve).not.toBeCalled()
+  })
+})