net

Built-in library for network access

Example usage

local net = require("@lune/net")

-- Sending a web request
local response = net.request("https://www.google.com")
print(response.ok)
print(response.statusCode, response.statusMessage)
print(response.headers)

-- Using a JSON web API
local response = net.request({
    url = "https://dummyjson.com/products/add",
    method = "POST",
    headers = { ["Content-Type"] = "application/json" },
    body = net.jsonEncode({
        title = "Cool Pencil",
    })
})
local product = net.jsonDecode(response.body)
print(product.id, "-", product.title)

-- Starting up a webserver
net.serve(8080, function(request)
    return {
        status = 200,
        body = "Echo:\n" .. request.body,
    }
end)

---

Functions

jsonDecode

function Net.jsonDecode(encoded: string)

Decodes the given JSON string into a lua value.

jsonEncode

function Net.jsonEncode(value: any, pretty: boolean?)

Encodes the given value as JSON.

request

function Net.request(config: string | FetchParams)

Sends an HTTP request using the given url and / or parameters, and returns a dictionary that describes the response received.

Only throws an error if a miscellaneous network or I/O error occurs, never for unsuccessful status codes.

serve

function Net.serve(port: number, handlerOrConfig: ServeHttpHandler | ServeConfig)

Creates an HTTP server that listens on the given port.

This will not block and will keep listening for requests on the given port until the stop function on the returned ServeHandle has been called.

socket

function Net.socket(url: string)

Connects to a web socket at the given URL.

Throws an error if the server at the given URL does not support web sockets, or if a miscellaneous network or I/O error occurs.

urlDecode

function Net.urlDecode(s: string, binary: boolean?)

Decodes the given string using URL decoding.

urlEncode

function Net.urlEncode(s: string, binary: boolean?)

Encodes the given string using URL encoding.

---

Types

FetchParams

type FetchParams = {
	url: string,
	method: HttpMethod?,
	query: { [string]: string }?,
	headers: { [string]: string }?,
	body: string?,
}

Parameters for sending network requests with net.request.

This is a dictionary that may contain one or more of the following values:

• url - The URL to send a request to. This is always required

• method - The HTTP method verb, such as "GET", "POST", "PATCH", "PUT", or "DELETE". Defaults to "GET"

• query - A table of key-value pairs representing query parameters in the request path

• headers - A table of key-value pairs representing headers

• body - The request body

FetchResponse

type FetchResponse = {
	ok: boolean,
	statusCode: number,
	statusMessage: string,
	headers: { [string]: string },
	body: string,
}

Response type for sending network requests with net.request.

This is a dictionary containing the following values:

• ok - If the status code is a canonical success status code, meaning within the range 200 -> 299

• statusCode - The status code returned for the request

• statusMessage - The canonical status message for the returned status code, such as "Not Found" for status code 404

• headers - A table of key-value pairs representing headers

• body - The request body, or an empty string if one was not given

HttpMethod

type HttpMethod = "GET" | "POST" | "PUT" | "DELETE" | "HEAD" | "OPTIONS" | "PATCH"

ServeConfig

type ServeConfig = {
	handleRequest: ServeHttpHandler?,
	handleWebSocket: ServeWebSocketHandler?,
}

Configuration for net.serve.

This may contain one of, or both of the following callbacks:

• handleRequest for handling normal http requests, equivalent to just passing a function to net.serve

• handleWebSocket for handling web socket requests, which will receive a WebSocket object as its first and only parameter

ServeHandle

type ServeHandle = {
	stop: () -> (),
}

A handle to a currently running web server, containing a single stop function to gracefully shut down the web server.

ServeHttpHandler

type ServeHttpHandler = (request: ServeRequest) -> string | ServeResponse

ServeRequest

type ServeRequest = {
	path: string,
	query: { [string]: string? },
	method: HttpMethod,
	headers: { [string]: string },
	body: string,
}

Data type for requests in net.serve.

This is a dictionary containing the following values:

• path - The path being requested, relative to the root. Will be / if not specified

• query - A table of key-value pairs representing query parameters in the request path

• method - The HTTP method verb, such as "GET", "POST", "PATCH", "PUT", or "DELETE". Will always be uppercase

• headers - A table of key-value pairs representing headers

• body - The request body, or an empty string if one was not given

ServeResponse

type ServeResponse = {
	status: number?,
	headers: { [string]: string }?,
	body: string?,
}

Response type for requests in net.serve.

This is a dictionary that may contain one or more of the following values:

• status - The status code for the request, in the range 100 -> 599

• headers - A table of key-value pairs representing headers

• body - The response body

ServeWebSocketHandler

type ServeWebSocketHandler = (socket: WebSocket) -> ()

WebSocket

type WebSocket = {
	closeCode: number?,
	close: (code: number?) -> (),
	send: (message: string, asBinaryMessage: boolean?) -> (),
	next: () -> string?,
}

A reference to a web socket connection.

The web socket may be in either an "open" or a "closed" state, changing its current behavior.

When open:

• Any function on the socket such as send, next or close can be called without erroring

• next can be called to yield until the next message is received or the socket becomes closed

When closed:

• next will no longer return any message(s) and instead instantly return nil

• send will throw an error stating that the socket has been closed

Once the websocket has been closed, closeCode will no longer be nil, and will be populated with a close code according to the WebSocket specification. This will be an integer between 1000 and 4999, where 1000 is the canonical code for normal, error-free closure.