lens/packages/technical-features/messaging/agnostic/src/features/unit-testing/get-message-bridge-fake/get-message-bridge-fake.test.ts

import {
  createContainer,
  DiContainer,
  Injectable,
} from "@ogre-tools/injectable";
import asyncFn, { AsyncFnMock } from "@async-fn/jest";
import { registerFeature } from "@k8slens/feature-core/src/register-feature";
import {
  getMessageChannelListenerInjectable,
  MessageChannel,
} from "../../actual/message/message-channel-listener-injection-token";
import { sendMessageToChannelInjectionToken } from "../../actual/message/message-to-channel-injection-token.no-coverage";
import { registerMobX } from "@ogre-tools/injectable-extension-for-mobx";
import { runInAction } from "mobx";
import {
  getRequestChannelListenerInjectable,
  RequestChannel,
} from "../../actual/request/request-channel-listener-injection-token";
import { requestFromChannelInjectionToken } from "../../actual/request/request-from-channel-injection-token.no-coverage";
import { getPromiseStatus } from "@k8slens/test-utils";
import { getMessageBridgeFake } from "./get-message-bridge-fake";
import { getMessageChannel } from "../../actual/message/get-message-channel";
import { getRequestChannel } from "../../actual/request/get-request-channel";
import { startApplicationInjectionToken } from "@k8slens/application";
import { messagingFeatureForUnitTesting } from "../feature";

[{ scenarioIsAsync: true }, { scenarioIsAsync: false }].forEach(
  ({ scenarioIsAsync }) =>
    describe(`get-message-bridge-fake, given running as ${
      scenarioIsAsync ? "async" : "sync"
    }`, () => {
      let messageBridgeFake: any;

      beforeEach(() => {
        messageBridgeFake = getMessageBridgeFake();
      });

      describe("given multiple DIs are involved", () => {
        let someDi1: DiContainer;
        let someDi2: DiContainer;
        let someDiWithoutListeners: DiContainer;

        beforeEach(async () => {
          someDi1 = createContainer("some-di-1");
          someDi2 = createContainer("some-di-2");

          someDiWithoutListeners = createContainer("some-di-3");

          registerMobX(someDi1);
          registerMobX(someDi2);
          registerMobX(someDiWithoutListeners);

          runInAction(() => {
            registerFeature(someDi1, messagingFeatureForUnitTesting);
            registerFeature(someDi2, messagingFeatureForUnitTesting);
            registerFeature(
              someDiWithoutListeners,
              messagingFeatureForUnitTesting
            );
          });

          messageBridgeFake.involve(someDi1, someDi2, someDiWithoutListeners);

          if (scenarioIsAsync) {
            messageBridgeFake.setAsync(scenarioIsAsync);
          }

          await Promise.all([
            someDi1.inject(startApplicationInjectionToken)(),
            someDi2.inject(startApplicationInjectionToken)(),
            someDiWithoutListeners.inject(startApplicationInjectionToken)(),
          ]);
        });

        describe("given there are message listeners", () => {
          let someHandler1MockInDi1: jest.Mock;
          let someHandler1MockInDi2: jest.Mock;
          let someHandler2MockInDi2: jest.Mock;
          let someListener1InDi2: Injectable<unknown, unknown>;

          beforeEach(() => {
            someHandler1MockInDi1 = jest.fn();
            someHandler1MockInDi2 = jest.fn();
            someHandler2MockInDi2 = jest.fn();

            const someListener1InDi1 = getMessageChannelListenerInjectable({
              id: "some-listener-in-di-1",
              channel: someMessageChannel,
              getHandler: () => someHandler1MockInDi1,
            });

            someListener1InDi2 = getMessageChannelListenerInjectable({
              id: "some-listener-in-di-2",
              channel: someMessageChannel,
              getHandler: () => someHandler1MockInDi2,
            });

            const someListener2InDi2 = getMessageChannelListenerInjectable({
              id: "some-listener-2-in-di-2",
              channel: someMessageChannel,
              getHandler: () => someHandler2MockInDi2,
            });

            runInAction(() => {
              someDi1.register(someListener1InDi1);
              someDi2.register(someListener1InDi2);
              someDi2.register(someListener2InDi2);
            });
          });

          describe("given there is a listener in di-2 that responds to a message with a message", () => {
            beforeEach(() => {
              const someResponder = getMessageChannelListenerInjectable({
                id: "some-responder-di-2",
                channel: someMessageChannel,

                getHandler: (di) => {
                  const sendMessage = di.inject(
                    sendMessageToChannelInjectionToken
                  );

                  return (message) => {
                    sendMessage(
                      someMessageChannel,
                      `some-response-to: ${message}`
                    );
                  };
                },
              });

              runInAction(() => {
                someDi2.register(someResponder);
              });
            });

            describe("given a message is sent in di-1", () => {
              beforeEach(() => {
                const sendMessageToChannelFromDi1 = someDi1.inject(
                  sendMessageToChannelInjectionToken
                );

                sendMessageToChannelFromDi1(someMessageChannel, "some-message");
              });

              describe(
                scenarioIsAsync
                  ? "when all message steps are propagated using a wrapper"
                  : "immediately",
                () => {
                  let someWrapper: jest.Mock;

                  beforeEach((done) => {
                    someWrapper = jest.fn((propagation) => propagation());

                    if (scenarioIsAsync) {
                      messageBridgeFake
                        .messagePropagationRecursive(someWrapper)
                        .then(done);
                    } else {
                      done();
                    }
                  });

                  it("the response gets handled in di-1", () => {
                    expect(someHandler1MockInDi1).toHaveBeenCalledWith(
                      "some-response-to: some-message"
                    );
                  });

                  scenarioIsAsync &&
                    it("the wrapper gets called with the both propagations", () => {
                      expect(someWrapper).toHaveBeenCalledTimes(2);
                    });
                }
              );

              describe(
                scenarioIsAsync
                  ? "when all message steps are propagated not using a wrapper"
                  : "immediately",
                () => {
                  beforeEach((done) => {
                    if (scenarioIsAsync) {
                      messageBridgeFake
                        .messagePropagationRecursive()
                        .then(done);
                    } else {
                      done();
                    }
                  });

                  it("the response gets handled in di-1", () => {
                    expect(someHandler1MockInDi1).toHaveBeenCalledWith(
                      "some-response-to: some-message"
                    );
                  });
                }
              );
            });
          });

          describe("when sending message in a DI", () => {
            beforeEach(() => {
              const sendMessageToChannelFromDi1 = someDi1.inject(
                sendMessageToChannelInjectionToken
              );

              sendMessageToChannelFromDi1(someMessageChannel, "some-message");
            });

            it("listener in sending DI does not handle the message", () => {
              expect(someHandler1MockInDi1).not.toHaveBeenCalled();
            });

            scenarioIsAsync &&
              it("listeners in other than sending DIs do not handle the message yet", () => {
                expect(someHandler1MockInDi2).not.toHaveBeenCalled();
                expect(someHandler2MockInDi2).not.toHaveBeenCalled();
              });

            describe(
              scenarioIsAsync ? "when messages are propagated" : "immediately",
              () => {
                beforeEach((done) => {
                  if (scenarioIsAsync) {
                    messageBridgeFake.messagePropagation().then(done);
                  } else {
                    done();
                  }
                });

                it("listeners in other than sending DIs handle the message", () => {
                  expect(someHandler1MockInDi2).toHaveBeenCalledWith(
                    "some-message"
                  );

                  expect(someHandler2MockInDi2).toHaveBeenCalledWith(
                    "some-message"
                  );
                });
              }
            );

            scenarioIsAsync &&
              describe("when messages are propagated using a wrapper, such as act() in react testing lib", () => {
                let someWrapper: jest.Mock;

                beforeEach(async () => {
                  someWrapper = jest.fn((observation) => observation());

                  await messageBridgeFake.messagePropagation(someWrapper);
                });

                it("the wrapper gets called with the related propagation", async () => {
                  expect(someWrapper).toHaveBeenCalledTimes(1);
                });

                it("listeners still handle the message", () => {
                  expect(someHandler1MockInDi2).toHaveBeenCalledWith(
                    "some-message"
                  );

                  expect(someHandler2MockInDi2).toHaveBeenCalledWith(
                    "some-message"
                  );
                });
              });
          });

          it("given a listener is deregistered, when sending message, deregistered listener does not handle the message", () => {
            runInAction(() => {
              someDi2.deregister(someListener1InDi2);
            });

            const sendMessageToChannelFromDi1 = someDi1.inject(
              sendMessageToChannelInjectionToken
            );

            someHandler1MockInDi2.mockClear();

            sendMessageToChannelFromDi1(someMessageChannel, "irrelevant");

            expect(someHandler1MockInDi2).not.toHaveBeenCalled();
          });
        });

        describe("given there are request listeners", () => {
          let someHandler1MockInDi1: AsyncFnMock<
            (message: string) => Promise<number>
          >;

          let someHandler1MockInDi2: AsyncFnMock<
            (message: string) => Promise<number>
          >;

          let someListener1InDi2: Injectable<unknown, unknown>;
          let actualPromise: Promise<number>;

          beforeEach(() => {
            someHandler1MockInDi1 = asyncFn();
            someHandler1MockInDi2 = asyncFn();

            const someListener1InDi1 = getRequestChannelListenerInjectable({
              id: "some-request-listener-in-di-1",
              channel: someOtherRequestChannel,
              getHandler: () => someHandler1MockInDi1,
            });

            someListener1InDi2 = getRequestChannelListenerInjectable({
              id: "some-request-listener-in-di-2",
              channel: someRequestChannel,
              getHandler: () => someHandler1MockInDi2,
            });

            runInAction(() => {
              someDi1.register(someListener1InDi1);
              someDi2.register(someListener1InDi2);
            });
          });

          describe("when requesting from a channel in a DI", () => {
            beforeEach(() => {
              const requestFromChannelFromDi1 = someDi1.inject(
                requestFromChannelInjectionToken
              );

              actualPromise = requestFromChannelFromDi1(
                someRequestChannel,
                "some-request"
              );
            });

            it("listener in requesting DI does not handle the request", () => {
              expect(someHandler1MockInDi1).not.toHaveBeenCalled();
            });

            it("the listener in other than requesting DIs handle the request", () => {
              expect(someHandler1MockInDi2).toHaveBeenCalledWith(
                "some-request"
              );
            });

            it("does not resolve yet", async () => {
              const promiseStatus = await getPromiseStatus(actualPromise);

              expect(promiseStatus.fulfilled).toBe(false);
            });

            it("when handle resolves, resolves with response", async () => {
              await someHandler1MockInDi2.resolve(42);

              const actual = await actualPromise;

              expect(actual).toBe(42);
            });
          });

          it("given a listener is deregistered, when requesting, deregistered listener does not handle the request", () => {
            runInAction(() => {
              someDi2.deregister(someListener1InDi2);
            });

            const sendMessageToChannelFromDi1 = someDi1.inject(
              sendMessageToChannelInjectionToken
            );

            someHandler1MockInDi2.mockClear();

            sendMessageToChannelFromDi1(someMessageChannel, "irrelevant");

            expect(someHandler1MockInDi2).not.toHaveBeenCalled();
          });

          it("given there are multiple listeners between different DIs for same channel, when requesting, throws", () => {
            const someConflictingListenerInjectable =
              getRequestChannelListenerInjectable({
                id: "conflicting-listener",
                channel: someRequestChannel,
                getHandler: () => () => 84,
              });

            runInAction(() => {
              someDi1.register(someConflictingListenerInjectable);
            });

            const requestFromChannelFromDi2 = someDi2.inject(
              requestFromChannelInjectionToken
            );

            return expect(() =>
              requestFromChannelFromDi2(someRequestChannel, "irrelevant")
            ).rejects.toThrow(
              'Tried to make a request but multiple listeners were discovered for channel "some-request-channel" in multiple DIs.'
            );
          });

          it("when requesting from channel without listener, throws", () => {
            const requestFromChannel = someDi1.inject(
              requestFromChannelInjectionToken
            );

            return expect(() =>
              requestFromChannel(
                someRequestChannelWithoutListeners,
                "irrelevant"
              )
            ).rejects.toThrow(
              'Tried to make a request but no listeners for channel "some-request-channel-without-listeners" was discovered in any DIs'
            );
          });
        });
      });
    })
);

type SomeMessageChannel = MessageChannel<string>;
type SomeRequestChannel = RequestChannel<string, number>;

const someMessageChannel: SomeMessageChannel = getMessageChannel(
  "some-message-channel"
);
const someRequestChannel: SomeRequestChannel = getRequestChannel(
  "some-request-channel"
);
const someOtherRequestChannel: SomeRequestChannel = {
  id: "some-other-request-channel",
};
const someRequestChannelWithoutListeners: SomeRequestChannel = {
  id: "some-request-channel-without-listeners",
};