--- a/netwerk/test/browser/browser_NetUtil.js
+++ b/netwerk/test/browser/browser_NetUtil.js
@@ -37,17 +37,17 @@ function test_asyncFetchBadCert() {
 
     // Now try again with a channel whose notificationCallbacks doesn't suprress errors
     let channel = NetUtil.newChannel({
       uri: "https://untrusted.example.com",
       loadUsingSystemPrincipal: true});
     channel.notificationCallbacks = {
       QueryInterface: XPCOMUtils.generateQI([Ci.nsIProgressEventSink,
                                              Ci.nsIInterfaceRequestor]),
-      getInterface: function (aIID) this.QueryInterface(aIID),
+      getInterface: function (aIID) { return this.QueryInterface(aIID); },
       onProgress: function () {},
       onStatus: function () {}
     };
     NetUtil.asyncFetch(channel, function (aInputStream, aStatusCode, aRequest) {
       ok(!Components.isSuccessCode(aStatusCode), "request failed");
       ok(aRequest instanceof Ci.nsIHttpChannel, "request is an nsIHttpChannel");
 
       // Now try a valid request

--- a/netwerk/test/httpserver/test/test_registerdirectory.js
+++ b/netwerk/test/httpserver/test/test_registerdirectory.js
@@ -40,17 +40,17 @@ function checkFile(ch, cx, status, data)
 {
   do_check_eq(ch.responseStatus, 200);
   do_check_true(ch.requestSucceeded);
 
   var actualFile = serverBasePath.clone();
   actualFile.append("test_registerdirectory.js");
   do_check_eq(ch.getResponseHeader("Content-Length"),
               actualFile.fileSize.toString());
-  do_check_eq(data.map(function(v) String.fromCharCode(v)).join(""),
+  do_check_eq(data.map(v => String.fromCharCode(v)).join(""),
               fileContents(actualFile));
 }
 
 XPCOMUtils.defineLazyGetter(this, "tests", function() {
   return [
 
 /***********************
  * without a base path *

--- a/netwerk/test/unit/test_bug894586.js
+++ b/netwerk/test/unit/test_bug894586.js
@@ -13,42 +13,65 @@ function ProtocolHandler() {
   this.uri = Cc["@mozilla.org/network/simple-uri;1"].
                createInstance(Ci.nsIURI);
   this.uri.spec = this.scheme + ":dummy";
   this.uri.QueryInterface(Ci.nsIMutable).mutable = false;
 }
 
 ProtocolHandler.prototype = {
   /** nsIProtocolHandler */
-  get scheme() "x-bug894586",
-  get defaultPort() -1,
-  get protocolFlags() Ci.nsIProtocolHandler.URI_NORELATIVE |
-                      Ci.nsIProtocolHandler.URI_NOAUTH |
-                      Ci.nsIProtocolHandler.URI_IS_UI_RESOURCE |
-                      Ci.nsIProtocolHandler.URI_IS_LOCAL_RESOURCE |
-                      Ci.nsIProtocolHandler.URI_NON_PERSISTABLE |
-                      Ci.nsIProtocolHandler.URI_SYNC_LOAD_IS_OK,
-  newURI: function(aSpec, aOriginCharset, aBaseURI) this.uri,
+  get scheme() {
+    return "x-bug894586";
+  },
+  get defaultPort() {
+    return -1;
+  },
+  get protocolFlags() {
+    return Ci.nsIProtocolHandler.URI_NORELATIVE |
+           Ci.nsIProtocolHandler.URI_NOAUTH |
+           Ci.nsIProtocolHandler.URI_IS_UI_RESOURCE |
+           Ci.nsIProtocolHandler.URI_IS_LOCAL_RESOURCE |
+           Ci.nsIProtocolHandler.URI_NON_PERSISTABLE |
+           Ci.nsIProtocolHandler.URI_SYNC_LOAD_IS_OK;
+  },
+  newURI: function(aSpec, aOriginCharset, aBaseURI) {
+    return this.uri;
+  },
   newChannel2: function(aURI, aLoadInfo) {
     this.loadInfo = aLoadInfo;
     return this;
   },
-  newChannel: function(aURI) this,
-  allowPort: function(port, scheme) port != -1,
+  newChannel: function(aURI) {
+    return this;
+  },
+  allowPort: function(port, scheme) {
+    return port != -1;
+  },
 
   /** nsIChannel */
-  get originalURI() this.uri,
-  get URI() this.uri,
+  get originalURI() {
+    return this.uri;
+  },
+  get URI() {
+    return this.uri;
+  },
   owner: null,
   notificationCallbacks: null,
-  get securityInfo() null,
-  get contentType() "text/css",
-  set contentType(val) void(0),
+  get securityInfo() {
+    return null;
+  },
+  get contentType() {
+    return "text/css";
+  },
+  set contentType(val) {
+  },
   contentCharset: "UTF-8",
-  get contentLength() -1,
+  get contentLength() {
+    return -1;
+  },
   set contentLength(val) {
     throw Components.Exception("Setting content length", NS_ERROR_NOT_IMPLEMENTED);
   },
   open: function() {
     var file = do_get_file("test_bug894586.js", false);
     do_check_true(file.exists());
     var url = Services.io.newFileURI(file);
     return Services.io.newChannelFromURI2(url,
@@ -77,19 +100,23 @@ ProtocolHandler.prototype = {
                                Cr.NS_ERROR_NOT_AVAILABLE);
   },
   get contentDispositionHeader() {
     throw Components.Exception("No header",
                                Cr.NS_ERROR_NOT_AVAILABLE);
   },
 
   /** nsIRequest */
-  get name() this.uri.spec,
-  isPending: function() false,
-  get status() Cr.NS_OK,
+  get name() {
+    return this.uri.spec;
+  },
+  isPending: () => false,
+  get status() {
+    return Cr.NS_OK;
+  },
   cancel: function(status) {},
   loadGroup: null,
   loadFlags: Ci.nsIRequest.LOAD_NORMAL |
              Ci.nsIRequest.INHIBIT_CACHING |
              Ci.nsIRequest.LOAD_BYPASS_CACHE,
 
   /** nsIFactory */
   createInstance: function(aOuter, aIID) {