Jaypie 🐦⬛
Event-driven fullstack architecture centered around JavaScript, AWS, and the JSON:API specification
"JavaScript on both sides and underneath"
🐦⬛ Introduction
Jaypie is an opinionated approach to application development centered around JavaScript and the JSON:API specification in an event-driven architecture.
Jaypie is suited for applications that require custom infrastructure beyond HTTP requests (e.g., message queues). Without custom infrastructure, fullstack hosts like Vercel or Netlify are recommended.
"Jaypie Stack"
- AWS infrastructure managed by CDK in Node.js
- Express server running on AWS Lambda
- Node.js worker processes running on AWS Lambda
- MongoDB via Mongoose
- Vue ecosystem frontend: Vue 3 composition, Vuetify, Pinia
- Vitest for testing
- ES6 syntax enforced via ESLint
- Prettier formatting
- JSON logging with custom metadata
Philosophy
Jaypie is for building fullstack JavaScript applications.
JavaScript Only 💛
Jaypie uses the AWS Cloud Development Kit (CDK) to manage infrastructure, which is written in Node.js. This makes managing infrastructure accessible to the fullstack developer without learning a new syntax and living without language constructs like loops and inheritance.
Does NOT use Kubernetes, Docker, Terraform, or the "Serverless" framework.
Eject Anything ⏏️
Jaypie embraces "ejectability," the philosophy that any part of the code can be removed (and therefore replaced) without disturbing the whole.
Mock Everywhere 🎴
Jaypie strives to be "mockable-first" meaning all components should be easily tested via default or provided mocks.
📋 Usage
Installation
Base Package
npm install jaypie
@jaypie/core
is included in jaypie
. Almost every Jaypie package requires core.
Peer Dependencies
You must install peer dependencies for your project.
Package | Exports | Description |
---|
@jaypie/aws | getSecret | AWS helpers |
@jaypie/lambda | lambdaHandler | Lambda entry point |
@jaypie/mongoose | connectFromSecretEnv , disconnect , mongoose | MongoDB management |
TestKit
Matchers, mocks, and utilities to test Jaypie projects.
npm install --save-dev @jaypie/testkit
Example
npm install jaypie @jaypie/lambda
const { InternalError, lambdaHandler, log } = require("jaypie");
export const handler = lambdaHandler(async({event}) => {
if (event.something === "problem") {
throw new InternalError();
}
return "Hello World";
}, { name: "example"});
This example would then be deployed to AWS via CDK or similar orchestration.
A @jaypie/cdk
package is intended
📖 Reference
AWS
import {
getMessages,
getSecret,
sendBatchMessages,
sendMessage,
} from "jaypie";
getMessages(event)
Return an array of message bodies from an SQS event.
import { getMessages } from '@jaypie/aws';
const messages = getMessages(event);
getSecret(secretName: string)
Retrieve a secret from AWS Secrets Manager using the secret name.
import { getSecret } from '@jaypie/aws';
const secret = await getSecret("MongoConnectionStringN0NC3-nSg1bR1sh");
sendBatchMessages({ messages, queueUrl })
Batch and send messages to an SQS queue. If more than ten messages are provided, the function will batch them into groups of ten or less (per AWS).
import { sendBatchMessages } from '@jaypie/aws';
const messages = [
{ salutation: "Hello, world!" },
{ salutation: "Hola, dushi!" },
];
const queueUrl = "https://sqs.us-east-1.amazonaws.com/123456789012/MyQueue";
await sendBatchMessages({ messages, queueUrl });
Parameter | Type | Required | Description |
---|
delaySeconds | number | No | Seconds to delay message delivery; default 0 |
messages | Array | Yes | Array of message objects (or strings) |
messageAttributes | object | No | Message attributes |
messageGroupId | string | No | Custom message group for FIFO queues; default provided |
queueUrl | string | Yes | URL of the SQS queue |
sendMessage({ body, queueUrl })
Send a single message to an SQS queue.
import { sendMessage } from '@jaypie/aws';
const body = "Hello, world!";
const queueUrl = "https://sqs.us-east-1.amazonaws.com/123456789012/MyQueue";
const response = await sendMessage({ body, queueUrl });
Parameter | Type | Required | Description |
---|
body | string | Yes | Message body |
delaySeconds | number | No | Seconds to delay message delivery; default 0 |
messageAttributes | object | No | Message attributes |
messageGroupId | string | No | Custom message group for FIFO queues; default provided |
queueUrl | string | Yes | URL of the SQS queue |
Constants
import {
CDK,
ERROR,
HTTP,
VALIDATE,
} from "jaypie";
CDK
CDK.ACCOUNT
CDK.ENV
CDK.ROLE
CDK.SERVICE
CDK.TAG
See constants.js in @jaypie/core.
ERROR
Default messages and titles for Jaypie errors.
See HTTP
for status codes.
HTTP
HTTP.ALLOW.ANY
HTTP.CODE
: OK
, CREATED
, ...HTTP.CONTENT.ANY
HTTP.CONTENT.HTML
HTTP.CONTENT.JSON
HTTP.CONTENT.TEXT
HTTP.HEADER
: ...HTTP.METHOD
: GET
, POST
, ...
VALIDATE
VALIDATE.ANY
- DefaultVALIDATE.ARRAY
VALIDATE.CLASS
VALIDATE.FUNCTION
VALIDATE.NUMBER
VALIDATE.NULL
VALIDATE.OBJECT
VALIDATE.STRING
VALIDATE.UNDEFINED
Internal Constants
JAYPIE
- for consistency across JaypiePROJECT
- for consistency across projects
Errors
Throwing/Catching Errors
const { InternalError } = require("@knowdev/errors");
try {
throw InternalError("Oh, I am slain!");
} catch (error) {
if(error.isProjectError) {
{
name,
title,
detail,
status,
} = error;
} else {
throw error;
}
}
Format Error
if(error.isProjectError) {
return error.json();
}
Multi-Error Usage
const errors = [];
errors.push(BadGatewayError());
errors.push(NotFoundError());
throw MultiError(errors);
Error Reference
Error | Status | Notes |
---|
BadGatewayError | 502 | Something I need gave me an error |
BadRequestError | 400 | You did something wrong |
ConfigurationError | 500 | "The developer" (probably you) or an associate did something wrong |
ForbiddenError | 403 | You are not allowed |
GatewayTimeoutError | 504 | Something I need is taking too long |
GoneError | 410 | The thing you are looking for was here but is now gone forever |
IllogicalError | 500 | Code is in a state that "should never happen" |
InternalError | 500 | General "something went wrong" |
MethodNotAllowedError | 405 | You tried a good path but the wrong method |
MultiError | Varies | Takes an array of errors |
NotFoundError | 404 | The thing you are looking for is not here and maybe never was |
NotImplementedError | 400 | "The developer" (you again?) didn't finish this part yet - hopefully a temporary message |
RejectedError | 403 | Request filtered prior to processing |
TeapotError | 418 | RFC 2324 section-2.3.2 |
UnavailableError | 503 | The thing you are looking for cannot come to the phone right now |
UnhandledError | 500 | An error that should have been handled wasn't |
UnreachableCodeError | 500 | Should not be possible |
Special Errors
ALWAYS internal to the app, NEVER something the client did
- Configuration
- "The person writing the code did something wrong" like forgot to pass or passed bad arguments
- "The person who configured the application made a mistake" like set mutually exclusive settings to true
- Illogical
- A combination of truth conditions occurred that should not be able to occur at the same time
- Not Implemented
- A marker to come back and finish this, but allows stubbing out HTTP endpoints
- Unhandled
- Internal to Jaypie, should not be thrown directly
- Jaypie expects code in handlers to handler errors and re-throw a Jaypie error
- If an unexpected error escapes the handler, Jaypie returns this when it is caught
- Unreachable
- In theory the block is literally not reachable and we want to put something there to make sure it stays that way
- For example, a complicated chain of
if
/else
that should always return and cover all cases, may throw this as the last else
- A configuration error means what happened was possible but should not have happened, an unreachable error means it should not have been possible
Functions
cloneDeep
lodash.clonedeep
from NPM
import { cloneDeep } from "jaypie";
const original = { a: 1, b: { c: 2 }};
const clone = cloneDeep(original);
envBoolean
Look up a key in process.env
and coerce it into a boolean.
Returns true
for true
(case-insensitive) and 1
for string, boolean, and numeric types.
Returns false
for false
(case-insensitive) and 0
for string, boolean, and numeric types.
Returns undefined
otherwise.
const { envBoolean } = require("@knowdev/functions");
process.env.AWESOME = true;
if (envBoolean("AWESOME")) {
console.log("Awesome!");
}
envBoolean
: defaultValue
const { envBoolean } = require("@knowdev/functions");
if (envBoolean("AWESOME", { defaultValue: true })) {
console.log("Awesome!");
}
force
Coerce a value into a type or throw an error.
Forcing arrays is the primary use case.
import { force } from "jaypie";
argument = force(thing, Array);
argument = force([thing], Array);
force
supports Array, Object, and String.
argument = force(argument, Array);
argument = force(argument, Object, "key");
argument = force(argument, String, "default");
argument = force.array(argument);
argument = force.object(argument, "key");
argument = force.string(argument);
getHeaderFrom(headerKey:string, searchObject:object)
Case-insensitive search inside searchObject
for headerKey
. Also looks in header
and headers
child object of searchObject
, if headerKey
not found at top-level.
placeholders
Lightweight string interpolation
import { placeholders } from "jaypie";
const string = placeholders("Hello, {name}!", { name: "World" });
The code for placeholders was written by Chris Ferdinandi and distributed under the MIT License in 2018-2019. Their web site is https://gomakethings.com
validate
import { validate, VALIDATE } from "jaypie";
validate(argument, {
type: VALIDATE.ANY,
falsy: false,
required: true,
throws: true
});
Validate Convenience Functions
import { validate } from "jaypie";
validate.array(argument);
validate.class(argument);
validate.function(argument);
validate.null(argument);
validate.number(argument);
validate.object(argument);
validate.string(argument);
validate.undefined(argument);
Intuitive Validate Types
Does not include any, class, or undefined
validate(argument, {
type: Array,
type: Function,
type: Number,
type: null,
type: Object,
type: String,
})
Jaypie Handler
The Jaypie handler can be used directly but is more likely to be wrapped in a more specific handler. The Jaypie handler will call lifecycle methods and provide logging. Unhandled errors will be thrown as UnhandledError
.
import { jaypieHandler } from "jaypie";
const handler = jaypieHandler(async(...args) => {
return "Hello World";
}, { name: "jaypieReference"});
Jaypie Lifecycle Methods
Each function receives the same arguments as the handler.
validate: [async Function]
Returns true
to validate the request. Throw an error or return false
to reject the request.
setup: [async Function]
Called before the handler (e.g., connect to a database). Throw an error to halt execution.
handler: async Function
The main function to handle the request. Throw an error to halt execution.
teardown: [async Function]
Called after the handler (e.g., disconnect from a database). Runs even if setup or handler throws errors.
Lambda Handler
The Lambda handler wraps the Jaypie handler that is specifically for AWS Lambda. It will call lifecycle methods and provide logging. Unhandled errors will be thrown as UnhandledError
.
const { lambdaHandler } = require("jaypie");
const handler = lambdaHandler(async({event}) => {
return "Hello World";
}, { name: "lambdaReference"});
Logging
import {
log,
} from "jaypie";
log
import { log } from "jaypie";
log.trace();
log.debug();
log.info();
log.warn();
log.error();
log.fatal();
log.lib({ lib: "myLib" })
Uses silent
by default. if process.env.MODULE_LOG_LEVEL
is true
, follows process.env.LOG_LEVEL
. If process.env.MODULE_LOG_LEVEL
is also set, uses that log level.
import { log } from "jaypie";
log.lib().trace();
log.lib({ lib: "myLib" }).trace();
log.tag(key, value) or log.tag({ key: value })
Permanently add the key-value pair to the logger's tags, or at least until log.untag(key)
is called.
import { log } from "jaypie";
log.tag("myTag", "myValue");
log.tag({ myTag: "myValue" });
log.untag(key) or log.untag([key1, key2, ...])
Remove the key-value pair from the logger's tags.
import { log } from "jaypie";
log.untag("myTag");
log.untag(["myTag1", "myTag2"]);
log.var(key, value) or log.var({ key: value })
Log a key-value pair. In the json
format, the key will be tagged as var
and the value will be the value. Logging marker variables this way can be useful for debugging.
import { log } from "jaypie";
log.var("message", "Hello, world");
log.var({ message: "Hello, world" });
const message = "Hello, world";
log.var({ message });
log.with() - clone
Create a new log object with additional tags
import { log as defaultLogger } from "jaypie";
const log = defaultLogger.with({ customProperty: "customValue" });
Mongoose
import {
connectFromSecretEnv,
disconnect,
mongoose,
} from "jaypie";
connectFromSecretEnv
Jaypie lifecycle method to connect to MongoDB using process.env.MONGO_CONNECTION_STRING
.
import { connectFromSecretEnv, disconnect, lambdaHandler, mongoose } from "jaypie";
const handler = lambdaHandler(async({event}) => {
return "Hello World";
}, {
name: "lambdaReference"
setup: [connectFromSecretEnv],
teardown: [disconnect],
});
disconnect
Jaypie lifecycle method to disconnect from MongoDB.
import { disconnect, lambdaHandler } from "jaypie";
const handler = lambdaHandler(async({event}) => {
}, {
teardown: [disconnect],
});
mongoose
mongoose
from NPM
import { mongoose } from "jaypie";
TestKit
npm install --save-dev @jaypie/testkit
Log Spying
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();
});
👺 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 () => {
await myNewFunction();
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();
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
TestKit Sundry
import {
jsonApiErrorSchema,
jsonApiSchema,
mockLogFactory,
} from '@jaypie/testkit'
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.
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
.
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();
});
🌠 Wishlist
@jaypie/cdk
- CDK package@jaypie/express
- Express package- ...Nicely organized VitePress documentation 😅
📝 Changelog
Date | Version | Summary |
---|
3/19/2024 | 1.0.0 | First publish with @jaypie/core@1.0.0 |
3/15/2024 | 0.1.0 | Initial deploy |
3/15/2024 | 0.0.1 | Initial commit |
📜 License
Published by Finlayson Studio. All rights reserved