Target localhost by default if $PORT is set, closes #146.

autocannon.js

@@ -5,6 +5,7 @@
 const minimist = require('minimist')
 const fs = require('fs')
 const path = require('path')
+const URL = require('url').URL
 const help = fs.readFileSync(path.join(__dirname, 'help.txt'), 'utf8')
 const run = require('./lib/run')
 const track = require('./lib/progressTracker')
@@ -64,6 +65,28 @@ function parseArguments (argvs) {
 
   argv.url = argv._[0]
 
+  // if PORT is set (like by `0x`), target `localhost:PORT/path` by default.
+  // this allows doing:
+  //     0x --on-port 'autocannon /path' -- node server.js
+  if (process.env.PORT) {
+    argv.url = new URL(argv.url, `http://localhost:${process.env.PORT}`).href
+  }
+  // Add http:// if it's not there and this is not a /path
+  if (argv.url.indexOf('http') !== 0 && argv.url[0] !== '/') {
+    argv.url = `http://${argv.url}`
+  }
+
+  // check that the URL is valid.
+  try {
+    new URL(argv.url) // eslint-disable-line no-new
+  } catch (err) {
+    console.error(err.message)
+    console.error('')
+    console.error('When targeting a path without a hostname, the PORT environment variable must be available.')
+    console.error('Use a full URL or set the PORT variable.')
+    process.exit(1)
+  }
+
   // support -n to disable the progress bar and results table
   if (argv.n) {
     argv.renderProgressBar = false

test/envPort.test.js

@@ -0,0 +1,61 @@
+'use strict'
+
+const t = require('tap')
+const split = require('split2')
+const path = require('path')
+const childProcess = require('child_process')
+const helper = require('./helper')
+
+const lines = [
+  /Running 1s test @ .*$/,
+  /10 connections.*$/,
+  /$/,
+  /Stat.*Avg.*Stdev.*Max.*$/,
+  /Latency \(ms\).*$/,
+  /Req\/Sec.*$/,
+  /Bytes\/Sec.*$/,
+  /$/,
+  /.* requests in \d+s, .* read/
+]
+
+t.plan(lines.length * 2 + 2)
+
+const server = helper.startServer()
+const port = server.address().port
+const url = '/path' // no hostname
+
+const child = childProcess.spawn(process.execPath, [path.join(__dirname, '..'), '-d', '1', url], {
+  cwd: __dirname,
+  env: Object.assign({}, process.env, {
+    PORT: port
+  }),
+  stdio: ['ignore', 'pipe', 'pipe'],
+  detached: false
+})
+
+t.tearDown(() => {
+  child.kill()
+})
+
+child
+  .stderr
+  .pipe(split())
+  .on('data', (line) => {
+    const regexp = lines.shift()
+    t.ok(regexp, 'we are expecting this line')
+    t.ok(regexp.test(line), 'line matches ' + regexp)
+  })
+  .on('end', () => {
+    t.ok(server.autocannonConnects > 0, 'targeted the correct port')
+  })
+
+const noPortChild = childProcess.spawn(process.execPath, [path.join(__dirname, '..'), url], {
+  cwd: __dirname,
+  env: process.env,
+  stdio: ['ignore', 'pipe', 'pipe'],
+  detached: false
+})
+
+noPortChild.on('exit', (code) => {
+  t.equal(code, 1, 'should exit with error when a hostless URL is passed and no PORT var is available')
+})