servo: Merge #5298 - Basic userscript support (from Manishearth:userscript); r=saneyuki

Gives us a place to store polyfills and other userscripts so that we can:

 - Quickly determine what DOM features are needed to make stuff like jQuery work by iteratively writing stub implementations
 - Write spec-incompatible but "good enough" polyfills for stuff like jQuery to make Servo more testable on live sites, for demos, and for browser.html


r? @jdm

cc @eddyb

Source-Repo: https://github.com/servo/servo
Source-Revision: 72e2c79a089ff6654a36951ce4aedac62006e6a1

servo/components/script/dom/htmlheadelement.rs

@@ -2,15 +2,24 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use dom::bindings::codegen::Bindings::ElementBinding::ElementMethods;
 use dom::bindings::codegen::Bindings::HTMLHeadElementBinding;
-use dom::bindings::codegen::InheritTypes::HTMLHeadElementDerived;
-use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
+use dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
+use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLHeadElementDerived, NodeCast};
+use dom::bindings::js::{JSRef, OptionalRootable, Temporary, RootedReference};
 use dom::document::Document;
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::element::ElementTypeId;
+use dom::element::AttributeHandlers;
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
-use dom::node::{Node, NodeTypeId};
+use dom::node::{Node, NodeHelpers, NodeTypeId};
+use dom::virtualmethods::VirtualMethods;
 use util::str::DOMString;
+use util::opts;
+use util::resource_files::resources_dir_path;
+use std::borrow::ToOwned;
+use std::fs::read_dir;
 
 #[dom_struct]
 pub struct HTMLHeadElement {
@@ -37,3 +46,40 @@ impl HTMLHeadElement {
     }
 }
 
+impl<'a> VirtualMethods for JSRef<'a, HTMLHeadElement> {
+    fn super_type<'b>(&'b self) -> Option<&'b VirtualMethods> {
+        let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
+        Some(htmlelement as &VirtualMethods)
+    }
+    fn bind_to_tree(&self, tree_in_doc: bool) {
+        if !opts::get().userscripts {
+            return;
+        }
+
+        let node: &JSRef<Node> = NodeCast::from_borrowed_ref(self);
+        let first_child = node.GetFirstChild().root();
+        let doc = node.owner_doc().root();
+        let doc = doc.r();
+
+        let mut path = resources_dir_path();
+        path.push("user-agent-js");
+        let mut files = match read_dir(&path) {
+            Ok(d) => d.filter_map(|e| e.ok()).map(|e| e.path()).collect::<Vec<_>>(),
+            Err(_) => return
+        };
+
+        files.sort();
+
+        for file in files {
+            let name = match file.into_os_string().into_string() {
+                Ok(ref s) if s.ends_with(".js") => "file://".to_owned() + &s[..],
+                _ => continue
+            };
+            let new_script = doc.CreateElement("script".to_owned()).unwrap().root();
+            let new_script = new_script.r();
+            new_script.set_string_attribute(&atom!("src"), name);
+            let new_script_node: &JSRef<Node> = NodeCast::from_borrowed_ref(&new_script);
+            node.InsertBefore(*new_script_node, first_child.r());
+        }
+    }
+}

servo/components/script/dom/virtualmethods.rs

@@ -11,6 +11,7 @@ use dom::bindings::codegen::InheritTypes::HTMLButtonElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLCanvasElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLFieldSetElementCast;
+use dom::bindings::codegen::InheritTypes::HTMLHeadElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLIFrameElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLImageElementCast;
 use dom::bindings::codegen::InheritTypes::HTMLInputElementCast;
@@ -39,6 +40,7 @@ use dom::htmlbuttonelement::HTMLButtonElement;
 use dom::htmlcanvaselement::HTMLCanvasElement;
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::htmlfieldsetelement::HTMLFieldSetElement;
+use dom::htmlheadelement::HTMLHeadElement;
 use dom::htmliframeelement::HTMLIFrameElement;
 use dom::htmlimageelement::HTMLImageElement;
 use dom::htmlinputelement::HTMLInputElement;
@@ -162,6 +164,10 @@ pub fn vtable_for<'a>(node: &'a JSRef<'a, Node>) -> &'a (VirtualMethods + 'a) {
             let element: &'a JSRef<'a, HTMLFieldSetElement> = HTMLFieldSetElementCast::to_borrowed_ref(node).unwrap();
             element as &'a (VirtualMethods + 'a)
         }
+        NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLHeadElement)) => {
+            let element: &'a JSRef<'a, HTMLHeadElement> = HTMLHeadElementCast::to_borrowed_ref(node).unwrap();
+            element as &'a (VirtualMethods + 'a)
+        }
         NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLImageElement)) => {
             let element: &'a JSRef<'a, HTMLImageElement> = HTMLImageElementCast::to_borrowed_ref(node).unwrap();
             element as &'a (VirtualMethods + 'a)

servo/components/util/opts.rs

@@ -59,6 +59,7 @@ pub struct Opts {
     pub nonincremental_layout: bool,
 
     pub nossl: bool,
+    pub userscripts: bool,
 
     pub output_file: Option<String>,
     pub headless: bool,
@@ -180,6 +181,7 @@ pub fn default_opts() -> Opts {
         layout_threads: 1,
         nonincremental_layout: false,
         nossl: false,
+        userscripts: false,
         output_file: None,
         headless: true,
         hard_fail: true,
@@ -220,6 +222,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
         getopts::optopt("y", "layout-threads", "Number of threads to use for layout", "1"),
         getopts::optflag("i", "nonincremental-layout", "Enable to turn off incremental layout."),
         getopts::optflag("", "no-ssl", "Disables ssl certificate verification."),
+        getopts::optflag("", "userscripts", "Uses userscripts in resources/user-agent-js"),
         getopts::optflag("z", "headless", "Headless mode"),
         getopts::optflag("f", "hard-fail", "Exit on task failure instead of displaying about:failure"),
         getopts::optflagopt("", "devtools", "Start remote devtools server on port", "6000"),
@@ -296,6 +299,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
 
     let nonincremental_layout = opt_match.opt_present("i");
     let nossl = opt_match.opt_present("no-ssl");
+    let userscripts = opt_match.opt_present("userscripts");
 
     let mut bubble_inline_sizes_separately = debug_options.contains(&"bubble-widths");
     let trace_layout = debug_options.contains(&"trace-layout");
@@ -331,6 +335,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
         layout_threads: layout_threads,
         nonincremental_layout: nonincremental_layout,
         nossl: nossl,
+        userscripts: userscripts,
         output_file: opt_match.opt_str("o"),
         headless: opt_match.opt_present("z"),
         hard_fail: opt_match.opt_present("f"),

servo/resources/user-agent-js/00.example.js

@@ -0,0 +1,5 @@
+// Keep files in this directory which you would like executed before
+// any other script when servo is run with `--userscripts`
+// Files are sorted alphabetically. When committing polyfills
+// order them with numbers, e.g. `01.innerhtml.js` will be executed before
+// `05.jquery.js`