Jaypie Testkit 🐦‍⬛🫒

Test utilities built for Jaypie

📋 Usage

Installation

npm install --save-dev @jaypie/testkit

Example

Mocking Jaypie

The testkit provides a complete mock for Jaypie including:

• Log spying (expect(log.warn).toHaveBeenCalled())
• Default responses for runtime-only functions (connect, sendMessage, submitMetric)
• No automatic error handling for handlers (which is good in production but obfuscates tests)
• Most non-utility functions are mocked to allow simple testing

vi.mock("jaypie", async () => vi.importActual("@jaypie/testkit/mock"));

Error Spying

import { ConfigurationError } from "@jaypie/core";

vi.mock("jaypie", async () => vi.importActual("@jaypie/testkit/mock"));

test("ConfigurationError", () => {
  try {
    throw new ConfigurationError("Sorpresa!");
  } catch (error) {
    expect(error).toBeJaypieError();
    expect(ConfigurationError).toHaveBeenCalled();
  }
});

Log Spying

import { log } from "jaypie";

vi.mock("jaypie", async () => vi.importActual("@jaypie/testkit/mock"));

afterEach(() => {
  vi.clearAllMocks();
});

test("log", () => {
  expect(vi.isMockFunction(log.warn)).toBe(true);
  expect(log.warn).not.toHaveBeenCalled();
  log.warn("Danger");
  expect(log.warn).toHaveBeenCalled();
  expect(log.error).not.toHaveBeenCalled();
});

👺 Logging Conventions:

• Only use log.trace or log.var during "happy path"
• Use log.debug for edge cases
• Now you can add an "observability" test that will fail as soon as new code triggers an unexpected edge condition

describe("Observability", () => {
  it("Does not log above trace", async () => {
    // Arrange
    // TODO: "happy path" setup
    // Act
    await myNewFunction(); // TODO: add any "happy path" parameters
    // Assert
    expect(log).not.toBeCalledAboveTrace();
    // or individually:
    expect(log.debug).not.toHaveBeenCalled();
    expect(log.info).not.toHaveBeenCalled();
    expect(log.warn).not.toHaveBeenCalled();
    expect(log.error).not.toHaveBeenCalled();
    expect(log.fatal).not.toHaveBeenCalled();
  });
});

👺 Follow the "arrange, act, assert" pattern

Test Matchers

testSetup.js

import { matchers as jaypieMatchers } from "@jaypie/testkit";
import * as extendedMatchers from "jest-extended";
import { expect } from "vitest";

expect.extend(extendedMatchers);
expect.extend(jaypieMatchers);

test.spec.js

import { ConfigurationError } from "@jaypie/core";

const error = new ConfigurationError();
const json = error.json();
expect(error).toBeJaypieError();
expect(json).toBeJaypieError();

📖 Reference

import { 
  LOG,
  jsonApiErrorSchema,
  jsonApiSchema,
  matchers,
  mockLogFactory,
  restoreLog,
  spyLog,
} from '@jaypie/testkit'

LOG

LOG constant provided by @jaypie/core for convenience

import { log } from "@jaypie/core";
import { LOG } from "@jaypie/testkit";

const libLogger = log.lib({ level: LOG.LEVEL.WARN, lib: "myLib" });

jsonApiErrorSchema

A JSON Schema validator for the JSON:API error schema. Powers the toBeJaypieError matcher (via toMatchSchema).

jsonApiSchema

A JSON Schema validator for the JSON:API data schema.

matchers

export default {
  toBeCalledAboveTrace,
  toBeCalledWithInitialParams,
  toBeClass,
  toBeJaypieError,
  toBeValidSchema: jsonSchemaMatchers.toBeValidSchema,
  toMatchBase64,
  toMatchJwt,
  toMatchMongoId,
  toMatchSchema: jsonSchemaMatchers.toMatchSchema,
  toMatchSignedCookie,
  toMatchUuid4,
  toMatchUuid5,
  toMatchUuid,
  toThrowBadGatewayError,
  toThrowBadRequestError,
  toThrowConfigurationError,
  toThrowForbiddenError,
  toThrowGatewayTimeoutError,
  toThrowInternalError,
  toThrowJaypieError,
  toThrowNotFoundError,
  toThrowUnauthorizedError,
  toThrowUnavailableError,
};

testSetup.js

import { matchers as jaypieMatchers } from "@jaypie/testkit";
import * as extendedMatchers from "jest-extended";
import { expect } from "vitest";

expect.extend(extendedMatchers);
expect.extend(jaypieMatchers);

expect(subject).toBeCalledAboveTrace()

import { log } from "@jaypie/core";

log.trace("Hello, World!");
expect(log).not.toBeCalledAboveTrace();

log.warn("Look out, World!");
expect(log).toBeCalledAboveTrace();

expect(subject).toBeJaypieError()

Validates instance objects:

try {
  throw new Error("Sorpresa!");
} catch (error) {
  expect(error).not.toBeJaypieError();
}

Validates plain old JSON:

expect({ errors: [ { status, title, detail } ] }).toBeJaypieError();

Jaypie errors, which are ProjectErrors, all have a .json() to convert

expect(subject).toBeValidSchema()

import { jsonApiErrorSchema, jsonApiSchema } from "@jaypie/testkit";

expect(jsonApiErrorSchema).toBeValidSchema();
expect(jsonApiSchema).toBeValidSchema();
expect({ project: "mayhem" }).not.toBeValidSchema();

From jest-json-schema toBeValidSchema.js (not documented in README)

expect(subject).toMatchSchema(schema)

import { jsonApiErrorSchema, jsonApiSchema } from "@jaypie/testkit";
import { ConfigurationError } from "@jaypie/core";

const error = new ConfigurationError();
const json = error.json();
expect(json).toMatchSchema(jsonApiErrorSchema);
expect(json).not.toMatchSchema(jsonApiSchema);

From jest-json-schema; see README

expect(subject).toMatch*() Regular Expression Matchers

Note: these regular expressions matchers so not verify the value is value, only that it matches the pattern (it "looks like" something). For example, expect("123e4567-e89b-12d3-a456-426614174000").toMatchUuid() will pass because the string matches a UUID pattern, even though it is not a valid UUID.

• toMatchBase64
• toMatchJwt
• toMatchMongoId
• toMatchSignedCookie
• toMatchUuid4
• toMatchUuid5
• toMatchUuid

expect(subject).toThrowJaypieError()

import { ConfigurationError } from "@jaypie/core";

const error = new ConfigurationError();
expect(() => {
  throw error;
}).toThrowJaypieError();

Do not forget to await expect when passing async functions:

import { ConfigurationError } from "@jaypie/core";

const error = new ConfigurationError();
await expect(async () => {
  throw error;
}).toThrowJaypieError();

// Breaks and causes a false-positive because `expect` did not `await`
// expect(async () => {}).toThrowJaypieError();
// > Error: Expected function to throw a JaypieError, but it did not throw.

mockLogFactory()

Creates a mock of the log provided by @jaypie/core.

import { mockLogFactory } from "@jaypie/testkit";

const log = mockLogFactory();
log.warn("Danger");
expect(log.warn).toHaveBeenCalled();
expect(log.error).not.toHaveBeenCalled();

restoreLog(log)

Restores the log provided by @jaypie/core, commonly performed afterEach with spyLog in beforeEach. See example with spyLog.

spyLog(log)

Spies on the log provided by @jaypie/core, commonly performed beforeEach with restoreLog in afterEach. Not necessary when mocking the entire Jaypie module.

import { restoreLog, spyLog } from "@jaypie/testkit";
import { log } from "@jaypie/core";

beforeEach(() => {
  spyLog(log);
});
afterEach(() => {
  restoreLog(log);
  vi.clearAllMocks();
});

test("log", () => {
  log.warn("Danger");
  expect(log.warn).toHaveBeenCalled();
  expect(log.error).not.toHaveBeenCalled();
});

sqsTestRecords(message, message, ...) or sqsTestRecords([...])

Generates an event object for testing SQS Lambda functions with as many messages as provided. Note, test will accept more than ten messages, but AWS will only send ten at a time.

import { sqsTestRecords } from "@jaypie/testkit";

const event = sqsTestRecords(
  { MessageId: "1", Body: "Hello, World!" },
  { MessageId: "2", Body: "Goodbye, World!" }
);

🌠 Wishlist

• matcher toBeHttpStatus
• matcher toBeJaypieAny
• matcher toBeJaypieData
• matcher toBeJaypieDataObject
• matcher toBeJaypieDataArray
• ...@knowdev/jest

📝 Changelog

Date	Version	Summary
9/15/2024	1.0.29	All errors exported as mocks
9/14/2024	1.0.28	Matchers toThrowBadGatewayError, toThrowGatewayTimeoutError, toThrowUnavailableError
9/13/2024	1.0.27	Matcher toBeCalledAboveTrace
7/16/2024	1.0.21	Export Jaypie mock as default
3/20/2024	1.0.2	Export LOG
3/16/2024	1.0.0	Artists ship
3/15/2024	0.1.0	Initial deploy
3/15/2024	0.0.1	Initial commit

📜 License

MIT License. Published by Finlayson Studio