firestore-vitest-mock/__tests__/transaction.test.ts

Vitest helper for mocking Google Cloud Firestore

import { beforeEach, describe, expect, vi, test, beforeAll } from "vitest";

import { mockFirebase } from "..";
import {
  mockRunTransaction,
  mockDelete,
  mockDeleteTransaction,
  mockUpdate,
  mockUpdateTransaction,
  mockSet,
  mockSetTransaction,
  mockGet,
  mockGetTransaction,
  mockGetAll,
  mockGetAllTransaction,
  mockCreateTransaction,
  Transaction,
} from "../mocks/firestore";

describe("Transactions", () => {
  mockFirebase({
    database: {},
  });

  let firebase;
  let db;

  beforeAll(async () => {
    firebase = await import("firebase");
    firebase.initializeApp({
      apiKey: "### FIREBASE API KEY ###",
      authDomain: "### FIREBASE AUTH DOMAIN ###",
      projectId: "### CLOUD FIRESTORE PROJECT ID ###",
    });
    db = firebase.firestore();
  });

  beforeEach(() => {
    vi.resetModules();
    vi.clearAllMocks();
  });

  test("it returns a Promise", () => {
    const result = db.runTransaction(async () => {});

    expect(result).toBeInstanceOf(Promise);
    expect(mockRunTransaction).toHaveBeenCalled();
  });

  test("it returns the same value returned by the transaction callback", async () => {
    const result = await db.runTransaction(() => "Success!");
    expect(result).toBe("Success!");
  });

  test("it provides a Transaction object", () => {
    const runner = vi.fn().mockReturnValue(Promise.resolve());
    const result = db.runTransaction(runner);

    expect(result).toBeInstanceOf(Promise);
    expect(runner).toHaveBeenCalled();
    expect(runner.mock.calls[0][0]).toBeInstanceOf(Transaction);
  });

  test("mockGet is accessible", async () => {
    expect.assertions(7);
    expect(mockGetTransaction).not.toHaveBeenCalled();
    const ref = db.collection("some").doc("body");

    await db.runTransaction(async (transaction) => {
      // `get` should return a promise
      const result = transaction.get(ref);
      expect(result).toBeInstanceOf(Promise);
      const doc = await result;

      // Calling `get` on transaction no longer calls `get` on `ref`
      expect(mockGet).not.toHaveBeenCalled();
      expect(doc).toHaveProperty("id", "body");
      expect(doc).toHaveProperty("exists", false);
      expect(doc.data()).toBeUndefined();
    });
    expect(mockGetTransaction).toHaveBeenCalled();
  });

  test("mockSet is accessible", async () => {
    expect.assertions(4);
    expect(mockSetTransaction).not.toHaveBeenCalled();
    const ref = db.collection("some").doc("body");

    await db.runTransaction((transaction) => {
      const newData = { foo: "bar" };
      const options = { merge: true };
      const result = transaction.set(ref, newData, options);

      expect(result).toBeInstanceOf(Transaction);
      expect(mockSet).toHaveBeenCalledWith(newData, options);
    });
    expect(mockSetTransaction).toHaveBeenCalled();
  });

  test("mockUpdate is accessible", async () => {
    expect.assertions(4);
    expect(mockUpdateTransaction).not.toHaveBeenCalled();
    const ref = db.collection("some").doc("body");

    await db.runTransaction((transaction) => {
      const newData = { foo: "bar" };
      const result = transaction.update(ref, newData);

      expect(result).toBeInstanceOf(Transaction);
      expect(mockUpdate).toHaveBeenCalledWith(newData);
    });
    expect(mockUpdateTransaction).toHaveBeenCalled();
  });

  test("mockDelete is accessible", async () => {
    expect.assertions(4);
    expect(mockDeleteTransaction).not.toHaveBeenCalled();
    const ref = db.collection("some").doc("body");

    await db.runTransaction(async (transaction) => {
      const result = transaction.delete(ref);

      expect(result).toBeInstanceOf(Transaction);
      expect(mockDelete).toHaveBeenCalled();
    });
    expect(mockDeleteTransaction).toHaveBeenCalled();
  });

  test("mockGetAll is accessible", async () => {
    expect.assertions(4);
    expect(mockGetAllTransaction).not.toHaveBeenCalled();
    const ref1 = db.collection("some").doc("body");
    const ref2 = ref1.collection("once").doc("told");

    await db.runTransaction(async (transaction) => {
      // FIXME: getAll is not defined on the client library, so this is a shot in the dark
      const result = await transaction.getAll(ref1, ref2);

      expect(result).toBeInstanceOf(Array);
      expect(mockGetAll).toHaveBeenCalled();
    });
    expect(mockGetAllTransaction).toHaveBeenCalled();
  });

  test("mockCreateTransaction is accessible", async () => {
    expect.assertions(2);
    expect(mockCreateTransaction).not.toHaveBeenCalled();
    // Example from documentation
    // https://googleapis.dev/nodejs/firestore/latest/Transaction.html#create-examples

    await db.runTransaction(async (transaction) => {
      const documentRef = db.doc("col/doc");
      return transaction.get(documentRef).then((doc) => {
        if (!doc.exists) {
          transaction.create(documentRef, { foo: "bar" });
        }
      });
    });

    expect(mockCreateTransaction).toHaveBeenCalled();
  });
});