pear-inspect

Enable debugging of Pear apps. This is especially useful when running terminal or mobile Pear apps. The apps can be running on a fully remote system, making it easier helping others debug their apps.

It's essentially a link between hyperdht and bare-inspector.

This is a part of how to debug Pear apps using Chrome Devtools Protocol (CDP).

Installation

``
npm install pear-inspect
`

Usage with pear://runtime

One of the reasons for using pear-inspect is to be able to debug with the pear://runtime application. To do so, all that's needed is to do this, in the app you want to inspect:

` js
import nodeInspector from 'inspector'
import { Inspector } from 'pear-inspect'

const inspector = new Inspector({ inspector: nodeInspector })
const inspectorKey = await inspector.enable()

console.log(Add this key to Pear Runtime: ${inspectorKey.toString('hex')})
`

Usage

The main thing to understand is that:

- On the app which that needs to be debuggged, use the Inspector class.
- On the other side (where you e.g. run your DevTools), use the Session class. This interface is similar to how Node's Inspector works with connect/disconnect/post methods.

On the app where inspection is needed:

` js
import nodeInspector from 'inspector'
import { Inspector } from 'pear-inspect'

const inspector = new Inspector({ inspector: nodeInspector })
const inspectorKey = await inspector.enable() // Pass the public key to the Session

// When inspection is no longer needed:
// await inspector.disable()
`

On the side where you want to debug the remote app:

` js
import { Session } from 'pear-inspect'

const session = new Session({ inspectorKey }) // The inspectorKey that was return from the Inspector
session.on('info', ({ filename }) => {
console.log('This is the main entrypoint', filename)
})
session.on('message', ({ id, result, error }) => {
console.log(result)
/*
{
result: {
type: 'number',
value: 3,
description: '3'
}
}
*/
})

session.connect()
session.post({
id: 1, // The id is optional, but is used by DevTools as it runs on jsonrpc
method: 'Runtime.evaluate',
params: { expression: '1 + 2' }
})

// When the session is no longer required (e.g. when the DevTools window is closed)
// session.disconnect()

// If the hyperdht connection should be completely stopped:
// await session.destroy()
`

Methods

$3

Creates new Inspector that will be able to inspect the process it's currently running.

If filename is omitted then it will be set to require.main.filename.

#### async .enable()

Enables inspection, creates a hyperdht server and returns inspectorKey.

If a dhtServer was passed, then it just attaches a 'connection' handler. If inspectorKey was passed, then this is used as a seed to generate a key pair which is then used for creating the hyperdht server.

#### async .disable()

Stops inspection and removes any hypderdht server.

If a dhtServer was passed, then it just detaches the 'connection' handler.

$3

Creates new Session that can inspect a remote app.

Either inspectorKey or publicKey has to be used. Generally you will use inspectorKey, but you can use publicKey if you want to have more control.

#### .connect()

Start the remote inspection. disconnect() can be called when inspection is no longer needed.

#### .disconnect()

Close the remote inspection. .connect() can be called again if more inspection is needed.

#### .post({ id, method, params })

Send a CDP method to the remote app. id is optional, but if passed, then it will be returned with the corresponding event.

Throws an error if .connect() has not been called

#### event .on('info', ({ filename }) => { ... })

When connected to the Inspector on the remote side, this event is emitted where it's possible to see which filename is the main entrypoint for the Pear app.

#### event .on('message', msg => { ... })

Messages from the remote app's inspector. Will contain id` if that was passed to the corresponding method.