Developing For Ray Developing a Ray Library

Developing a Ray Library

The Ray app is not a language-specific debugging app - as long as there's an integration library, it can be used with any language.

If you're interested in developing a Ray library for your language of choice, this document will help guide you through the process. As an example, we'll be creating an example Ray integration library for JavaScript/Node.js; however, the concepts apply to any language.

#Creating a JavaScript integration for Ray

In this guide, we'll create a new JavaScript library that communicates with Ray. There are already comprehensive third-party libraries in this space, such as node-ray, but this will serve well as an example.

#Goals

Create a JavaScript library that communicates with Ray that implements the following methods:

  • color()
  • html()
  • ray()
  • charles()
  • send()
  • sendRequest()

#Getting started

The spatie/ray PHP package should be used as a reference - it is the primary library for Ray, and all new functionality is always added here first. We'll reference its source code as we write our library.

Create a new directory named ray-library-reference, and run:

cd ./ray-library-reference
composer init
composer require spatie/ray

Next, create a PHP script for testing:

<?php

// ray-test.php

require_once(__DIR__.'/vendor/autoload.php');

ray('test one')->color('red');
ray()->html('<strong>this is a bold</strong>')->color('blue');
ray()->send('this is a test');

#Tools

To help determine what payload data is actually being sent to Ray from our test PHP script, we'll use the third-party permafrost-dev/ray-proxy package to intercept and display all payloads being sent to Ray.

When you're ready to start intercepting data, start Ray app and set the port to 23516 in the preferences. Then start ray-proxy:

npx ray-proxy

#Technology/package choices

For the development, we'll use TypeScript as the primary language and the esbuild package to compile and bundle our library.

We'll use the superagent npm package for sending data to Ray, and the uuid package for generating the required UUIDv4 values for creating valid payloads.

cd ./ray-lib-app

npm install --save-dev typescript esbuild
npm install superagent uuid

Next, let's set up our project:

mkdir ./src
mkdir ./dist

touch ./dist/test.js
touch ./src/Origin.ts
touch ./src/Ray.ts
touch ./src/payloadUtils.ts

#Structure of a Payload

Let's start with the raw contents of a payload that is sent from your code to the Ray app. You may view it in ray-proxy by running the following:

php ./ray-library-reference/ray-test.php

{
  "uuid": "ca539a19-afd7-4c5e-8142-0d4b94512241",
  "payloads": [
    {
      "type": "custom",
      "content": {
        "content": "string 1 1615239018342",
        "label": "HTML"
      },
      "origin": {
        "function_name": "test",
        "file": "/home/user/projects/test-project/test.js",
        "line_number": 16,
        "hostname": "my-hostname"
      }
    }
  ],
  "meta": {
    "php_version": "7.4.16",
    "php_version_id": 70416,
    "ray_package_version": "1.20.1.0"
  }
}

Here we see that a payload has 3 parts: the type, the content, and the origin.

Sent along with the payload is a UUIDv4 and a meta object, which contains the name and version of the Ray library we're using.

The uuid property is critical: it's used by the Ray app to identify each payload. Ray allows libraries to modify the value of payloads that have already been sent by sending subsequent payloads with the same uuid value.

Since this is a basic walk though, we'll use hard-coded Origin data - information about where the call originated within the source code, placed in ./src/Origin.ts.

Integration libraries must implement a working Origin class so the information displayed in Ray is correct.

// src/Origin.ts
export const OriginData = {
	function_name: 'my_test_func',
	file: 'my-file.js',
	line_number: 16,
	hostname: 'my-hostname',
};

Then create ./src/payloadUtils.ts, which will contain helper functions for creating payloads:

// src/payloadUtils.ts
import { v4  as  uuidv4 } from  'uuid';
import { OriginData } from './Origin';

// create the actual payload to send using the structure from above
export function createSendablePayload(payloads: any[] = [], uuid: string | null = null): any {
	uuid = uuid ?? uuidv4({}).toString();

	return { uuid, payloads, meta: { my_package_version: "1.0.0" } };
}

// create a generic payload object.
// in an actual library, we'd create separate Payload classes for each type.
export function createPayload(type: string, label: string | undefined, content: any, contentName: string = 'content'): any {
	let result = {
		type: type,
		content: {
	        [contentName]: content,
	        label: label,
        },
        origin: OriginData,
	};

	if (result.content.label === undefined) {
		delete result.content['label'];
	}

	return result;
}

// change the color of a previously sent payload in Ray
export function createColorPayload(colorName: string, uuid: string | null = null) {
	const payload = createPayload('color', undefined, colorName, 'color');
	return createSendablePayload([payload], uuid);
}

// create an "HTML" payload to display custom HTML in Ray
export function createHtmlPayload(htmlContent: string, uuid: string | null = null) {
	const payload = createPayload('custom', 'HTML', htmlContent);
	return createSendablePayload([payload], uuid);
}

// create a "log" payload to display basic text in Ray
export function createLogPayload(text: string|string[], uuid: string | null = null) {
	const payload = createPayload('log', 'log', text);
	return createSendablePayload([payload], uuid);
}

Now, we'll need to create the main Ray class: ./src/Ray.ts.

All integration libraries should implement a Ray class. When creating an integration library, you should create separate Payload classes for each method (see spatie/ray for examples).

import { createLogPayload, createColorPayload, createHtmlPayload } from './payloadUtils';
const  superagent = require('superagent');

export class Ray {
	public uuid: string | null = null;

	// change the color of the payload
	public color(name: string): Ray {
		const payload = createColorPayload(name, this.uuid);

		return this.sendRequest(payload);
	}

	// send custom html to Ray
	public html(name: string): Ray {
		const payload = createHtmlPayload(name, this.uuid);

		return this.sendRequest(payload);
	}

    // send an arbitrary number of arguments of any type to Ray
	public send(...args: any[]): Ray {
		args.forEach(arg => {
			const payload = createLogPayload('log', null, arg);
			this.sendRequest(payload);
		});

		return this;
	}

	public charles(): Ray {
	    return this.send('🎶 🎹 🎷 🕺');
    }

	// send a payload object to Ray
	public sendRequest(payload: any): Ray {
		this.uuid = request.uuid;

        superagent.post(`http://localhost:23517/`).send(payload)
	        .then(resp => { })
	        .catch(err => {});

		return this;
	}
}

export default Ray;

#Building the library

We'll be using ESBuild to compile our library, which is a very fast ECMA and Typescript compiler built in golang.

The following command tells ESBuild to bundle all files into a single output file, that it will be run on the node platform (instead of in a browser), to target node v12 as the minimum node version to support, and to treat the superagent npm package as external (meaning it should not be packaged as part of our outfile).

./node_modules/.bin/esbuild --bundle \
  --target=node12 --platform=node \
  --format=cjs --external:superagent \
  --outfile=dist/index.js src/Ray.ts

if you'd like to add a shortcut, modify the scripts section in your package.json file to the following:

  "scripts": {
    "build": "./node_modules/.bin/esbuild --bundle --target=node12 --platform=node --format=cjs --external:superagent --outfile=dist/index.js src/Ray.ts"
  },

Once saved, you may run the npm run build command instead of the ./node_modules/.bin/esbuild … command.

After running the build command you choose, you'll see that the file ./dist/index.js has been created.

Finally, we're ready to test our library.

#Testing the library

First, edit the file named ./dist/test.js:

// ./dist/test.js
const { Ray } = require('./index');

(new Ray()).html('<em>hello world</em>').color('red');
(new Ray()).send('Hello World!').color('blue');

Finally, make sure the Ray app is running and run the following command in your terminal:

node ./dist/test.js

With any luck, you'll see the message "hello world" with a red marker next to it in the Ray app - but not the "hello world 2" blue message.

#Debugging issues

If you were to test the send() method, you'd notice that nothing appears in the Ray app. No problem, though - since we've got access to the PHP package as well as the ray-proxy app running, we can debug this in no time.

Here's what is being sent from our library to Ray, according to the proxy:

{
  "uuid": "8bd2e386-e000-47b6-bd31-a655fd66376d",
  "payloads": [
    {
      "type": "log",
      "content": {
        "content": "log",
        "label": "log"
      },
      "origin": {
        "function_name": "my_test_func",
        "file": "my-file.js",
        "line_number": 16,
        "hostname": "my-hostname"
      }
    }
  ],
  "meta": {
    "my_package_version": "1.0.0"
  }
}

Run the following, to see what we should be sending:

php ./ray-library-reference/ray-test.php

And here's what SHOULD be sent (relevant parts only):

{
  …
  "payloads": [
    {
      "type": "log",
      "content": {
        "values": [
          "Hello World!"
        ]
      },
	…
    }
  ],
  "meta": {
	…
  }
}

The issue appears to be with our createLogPayload function, so let's change a few things:

export function createLogPayload(text: string|string[], uuid: string | null = null) {
	// make sure we pass an array of values
    if (!Array.isArray(text)) {
        text = [text];
    }
    // add the last parameter to send "content.values" in the payload
	const payload = createPayload('log', 'log', text, 'values');
	return createSendablePayload([payload], uuid);
}

And lastly, we need to update the send() method on the Ray class:

public send(...args: any[]): Ray {
    // we only need to send a single payload with `args` as the data, instead of
    // sending a new payload for each arg in args.
	const payload = createLogPayload(args, this.uuid);
	this.sendRequest(payload);

	return this;
}

Let's compile again, and re-run our test script:

./node_modules/.bin/esbuild --bundle \
  --target=node12 --platform=node \
  --format=cjs --external:superagent \
  --outfile=dist/index.js src/Ray.ts

node dist/test.js

Success! You should see two "hello world" messages, one red and one blue.

Let's add one more feature to make using our library more pleasant - a ray() helper function.

Integration libraries must provide a global ray() helper method to maintain consistency with the other libraries.

// … Ray class code here

export function ray(...args: any[]) {
    return (new Ray()).send(...args);
}

export default Ray;

You can now modify your test script to something like:

// dist/test.js
const { ray } = require('./index');

ray('hello world').color('red');
ray().html('<strong>bold text</strong>');

That's it! Make sure to take a look at the companion repository to check out the final project code.

Don't forget to stop the ray-proxy app and change your Ray port back to its original value (defaults to 23517).

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