new_app_process: Run a webfakes app in another process

Description

Runs an app in a subprocess, using callr::r_session.

Usage

new_app_process(
  app,
  port = NULL,
  opts = server_opts(remote = TRUE),
  start = FALSE,
  auto_start = TRUE,
  process_timeout = NULL,
  callr_opts = NULL
)

Value

A webfakes_app_process object.

Methods

The webfakes_app_process class has the following methods:

get_app()
get_port()
stop()
get_state()
local_env(envvars)
url(path = "/", query = NULL)

envvars: Named list of environment variables. The {url} substring is replaced by the URL of the app.
path: Path to return the URL for.
query: Additional query parameters, a named list, to add to the URL.

get_app() returns the app object.

get_port() returns the port the web server is running on.

stop() stops the web server, and also the subprocess. If the error log file is not empty, then it dumps its contents to the screen.

get_state() returns a string, the state of the web server:

"not running" the server is not running (because it was stopped already).
"live" means that the server is running.
"dead" means that the subprocess has quit or crashed.

local_env() sets the given environment variables for the duration of the app process. It resets them in $stop(). Webfakes replaces {url} in the value of the environment variables with the app URL, so you can set environment variables that point to the app.

url() returns the URL of the web app. You can use the path parameter to return a specific path.

Arguments

app: webfakes_app object, the web app to run.
port: Port to use. By default the OS assigns a port.
opts: Server options. See server_opts() for the defaults.
start: Whether to start the web server immediately. If this is FALSE, and auto_start is TRUE, then it is started as neeed.
auto_start: Whether to start the web server process automatically. If TRUE and the process is not running, then $start(), $get_port() and $url() start the process.
process_timeout: How long to wait for the subprocess to start, in milliseconds.
callr_opts: Options to pass to callr::r_session_options() when setting up the subprocess.

Examples

Run this code

app <- new_app()
app$get("/foo", function(req, res) {
  res$send("Hello world!")
})

proc <- new_app_process(app)
url <- proc$url("/foo")
resp <- curl::curl_fetch_memory(url)
cat(rawToChar(resp$content))

proc$stop()