API

``js
const RPC = require('@exodus/json-rpc');
const clientOrServer = new RPC({ transport, requestTimeout, methods });

const result = await clientOrServer.callMethod(
(methodName: String),
(parameters: Array)
);
clientOrServer.notify((methodName: String), (parameters: Array)); // same as above but one way only

clientOrServer.exposeMethods({
methodName: params => result // can return promise
});

// same as exposeMethods but allows to add functions one by one
clientOrServer.exposeFunction('methodName', params => result);
`

transport is object stream like, anything that implements write() method and on('data', ...) event

Example usage:

`js
const EventEmitter = require('events')
const RPC = require('@exodus/json-rpc')

const transport1 = new EventEmitter()
const transport2 = new EventEmitter()
transport1.write = (data) => {
console.log('Transport1 write: ', data)
setTimeout(() => {
console.log('Emitting data2:', data)
transport2.emit('data', data)
}, 500)
}
transport2.write = (data) => {
console.log('Transport2 write: ', data)
setTimeout(() => {
console.log('Emitting data1:', data)
transport1.emit('data', data)
}, 500)
}

const server1 = new RPC({ transport: transport1 })
const server2 = new RPC({ transport: transport2 })

server2.exposeMethods({
testMethod1: (a, b) => {
console.log('Here!', a, b)
throw new Error('oops')
return a + b
},
testMethod2: (a, b) => {
return Promise.resolve(123)
},
testMethod3: (a, b) => {
return
},
})

server1.exposeMethods({
foo: () => {
throw new Error('oops')
},
})

async function main() {
const sum = await server1.callMethod('testMethod1', [22, 33])
console.log(sum)
await server2.notify('foo')
await server2.notify('XXX')

// get the raw response object when making a method call:
const {
id,
jsonrpc,
error,
result: sum,
} = server1.callMethodWithRawResponse('testMethod1', [22, 33])
console.log(sum)
}

main().catch(console.log)
`

When the transport emits a message, by default RPC will parse the message with JSON.parse. You can customize this with your own parsing function by specifying the parse constructor option.

`js
const rpc = new RPC({
transport,
parse: (jsonString) => {
// Enforce a maximum message size
if (jsonString.length > 1000) throw new Error('message is too long')

// Log messages as they are parsed
console.log(New message: ${jsonString})

return JSON.parse(jsonString)
},
})
``