feat: support axios proxy (#402)

Co-authored-by: Philip Peterson <philip-peterson@users.noreply.github.com>

Author: philip-peterson

README.md

@@ -195,6 +195,16 @@ See `demo-expect-403` NPM script.
 
 Default expected value is 200.
 
+#### proxy
+
+You can have requests to the resolved URL be passed through a proxy server. To do this, specify both the `--proxy-host` and `--proxy-port` arguments. For example, specifying these as `localhost` and `8000` will pass requests through the proxy server at `localhost:8000`.
+
+```
+$ start-test --proxy-host localhost --proxy-port 8000 start :9000 test:e2e
+```
+
+Authentication is also supported, as well as custom protocol for the proxy (e.g. `socks5` or `https`), through the `--proxy-user`, `--proxy-password`, and `--proxy-protocol` options.
+
 ## `npx` and `yarn`
 
 If you have [npx](https://www.npmjs.com/package/npx) available, you can execute locally installed tools from the shell. For example, if the `package.json` has the following local tools:

src/index.js

@@ -86,6 +86,28 @@ function waitAndRun ({ start, url, runFn, namedArguments }) {
     server.on('close', onClose)
 
     debug('starting waitOn %s', url)
+
+    let proxy
+    if (namedArguments.proxyHost) {
+      if (!namedArguments.proxyPort) {
+        throw new Error('Proxy host provided but no port provided')
+      }
+      proxy = {
+        host: namedArguments.proxyHost,
+        port: namedArguments.proxyPort,
+        protocol: namedArguments.proxyProtocol
+      }
+      if (namedArguments.proxyUser) {
+        if (typeof namedArguments.proxyPassword !== 'string') {
+          throw new Error('Proxy username provided but no password provided')
+        }
+        proxy.auth = {
+          username: namedArguments.proxyUser,
+          password: namedArguments.proxyPassword
+        }
+      }
+    }
+
     const options = {
       resources: Array.isArray(url) ? url : [url],
       interval: waitOnInterval,
@@ -97,7 +119,8 @@ function waitAndRun ({ start, url, runFn, namedArguments }) {
       headers: {
         Accept: 'text/html, application/json, text/plain, */*'
       },
-      validateStatus
+      validateStatus,
+      proxy
     }
     debug('wait-on options %o', options)
 

src/utils.js

@@ -6,7 +6,13 @@ const arg = require('arg')
 const debug = require('debug')('start-server-and-test')
 
 const namedArguments = {
-  '--expect': Number
+  '--expect': Number,
+
+  '--proxy-host': String,
+  '--proxy-protocol': String,
+  '--proxy-port': Number,
+  '--proxy-user': String,
+  '--proxy-pass': String
 }
 
 /**
@@ -65,6 +71,11 @@ const getNamedArguments = cliArgs => {
   debug('initial parsed arguments %o', args)
   return {
     expect: args['--expect'],
+    proxyHost: args['--proxy-host'],
+    proxyUser: args['--proxy-user'],
+    proxyPassword: args['--proxy-password'],
+    proxyPort: args['--proxy-port'],
+    proxyProtocol: args['--proxy-protocol'],
     // aliases
     '--expected': '--expect'
   }