Allow file urls

lib/pac/resolver.js

@@ -6,33 +6,57 @@ const url = require('url')
 const request = require('request')
 const pac = require('pac-resolver')
 const local = require('./local-address')
+const fs = require('fs');
 
 const defaults = {
   url: undefined,
   auth: undefined
 }
 
-module.exports = (options) => {
+const FILE_PROTOCOL = 'file://';
+
+function retrievePacFile(url) {
+  return new Promise((resolve, reject) => {
+    debug('retrieving proxy.pac at %j', url)
+
+    if (!url.startsWith(FILE_PROTOCOL)) {
+      request(
+        {
+          url: url,
+          proxy: false
+        },
+        (err, res, body) => {
+          if (err) {
+            return reject(err);
+          } else if (Math.floor(res.statusCode / 100) !== 2) {
+            return reject(new Error(res.statusMessage))
+          }
+
+          debug('proxy.pac retrieved')
+          return resolve(body)
+        }
+      );
+    } else {
+      fs.readFile(url.substr(FILE_PROTOCOL.length), (err, contents) => {
+        if (err) {
+          return reject(err)
+        } else {
+          return resolve(contents)
+        }
+      })
+    }
+  })
+}
+
+module.exports = async (options) => {
 
   options = _.defaults(options, defaults)
 
   if (typeof options.url === 'undefined') {
     throw new Error('missing url parameter')
   }
-
-  return new Promise((resolve, reject) => {
 
-    debug('retrieving proxy.pac at %j', options.url)
-    request({
-      url: options.url,
-      proxy: false
-    }, (err, res, body) => {
-      if (err) {
-	return reject(err)
-      } else if (Math.floor(res.statusCode / 100) !== 2) {
-	return reject(new Error(res.statusMessage))
-      }
-      debug('proxy.pac retrieved')
+    const body = await retrievePacFile(options.url)
 
       try {
 	const resolver = pac(body, {
@@ -42,8 +66,7 @@ module.exports = (options) => {
 	})
 
 	debug('returning resolver for proxy.pac at %j', options.url)
-	return resolve((uri) => {
-	  return new Promise(async (resolve, reject) => {
+	return async (uri) => {
 	    debug('resolving proxy for %j', uri)
 	    try {
 	      if (await local.check(url.parse(uri).hostname)) {
@@ -57,23 +80,20 @@ module.exports = (options) => {
 	      } else {
 		uri = url.parse(uri)
 	      }
-	      return resolve({
+	      return {
 		connection: verb,
 		host: uri.hostname,
 		port: (uri.port ? uri.port :
 		       (uri.protocol === 'https:' ? 443 : 80)),
 		auth: (proxy ? options.auth : undefined)
-	      })
+	      }
 	    } catch (err) {
 	      debug('error resolving %j: %O', uri, err)
-	      return reject(err)
+	      throw err
 	    }
-	  })
-	})
-      } catch (err) {
+	  }
+    } catch (err) {
 	debug('error creating resolver for proxy.pac at %j', options.url)
-	return reject(err)
-      }
-    })
-  })
+	throw err
+    }
 }