Tidy finds WebIDLs with no spec.

Closes #6689

components/script/dom/webidls/BrowserElement.webidl

@@ -4,6 +4,8 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+// https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser
+
 callback BrowserElementNextPaintEventCallback = void ();
 
 //dictionary BrowserElementDownloadOptions {

components/script/dom/webidls/CanvasPattern.webidl

@@ -3,6 +3,8 @@
  * 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/. */
 
+// https://html.spec.whatwg.org/multipage/scripting.html#canvaspattern
+
 interface CanvasPattern {
   //void setTransform(SVGMatrix matrix);
 };

components/script/dom/webidls/ErrorEvent.webidl

@@ -2,6 +2,8 @@
  * 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/. */
 
+// https://html.spec.whatwg.org/multipage/webappapis.html#the-errorevent-interface 
+
 [Constructor(DOMString type, optional ErrorEventInit eventInitDict)/*, Exposed=(Window,Worker)*/]
 interface ErrorEvent : Event {
   readonly attribute DOMString message;

components/script/dom/webidls/HTMLCollection.webidl

@@ -3,6 +3,8 @@
  * 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/. */
 
+// http://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-75708506
+
 interface HTMLCollection {
   readonly attribute unsigned long length;
   getter Element? item(unsigned long index);

components/script/dom/webidls/NamedNodeMap.webidl

@@ -2,6 +2,8 @@
  * 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/. */
 
+// https://dom.spec.whatwg.org/#interface-namednodemap
+
 interface NamedNodeMap {
   readonly attribute unsigned long length;
   getter Attr? item(unsigned long index);

components/script/dom/webidls/ServoHTMLParser.webidl

@@ -3,6 +3,9 @@
  * 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/. */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 // FIXME: find a better way to hide this from content (#3688)
 [NoInterfaceObject]
 interface ServoHTMLParser {

components/script/dom/webidls/TestBinding.webidl

@@ -2,6 +2,9 @@
  * 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/. */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 enum TestEnum { "", "foo", "bar" };
 
 dictionary TestDictionary {

components/script/dom/webidls/TestBindingProxy.webidl

@@ -9,6 +9,9 @@
  *
  */
 
+// This interface is entirely internal to Servo, and should not be accessible to
+// web pages.
+
 interface TestBindingProxy : TestBinding {
 
   getter DOMString getNamedItem(DOMString name);

components/script/dom/webidls/WebSocket.webidl

@@ -2,6 +2,8 @@
  * 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/. */
 
+// https://w3c.github.io/websockets/#the-websocket-interface
+
 enum BinaryType { "blob", "arraybuffer" };
 
 [Constructor(DOMString url)]

python/tidy.py

@@ -15,7 +15,7 @@ import sys
 import toml
 from licenseck import licenses
 
-filetypes_to_check = [".rs", ".rc", ".cpp", ".c", ".h", ".py", ".toml"]
+filetypes_to_check = [".rs", ".rc", ".cpp", ".c", ".h", ".py", ".toml", ".webidl"]
 reftest_directories = ["tests/ref"]
 reftest_filetype = ".list"
 python_dependencies = [
@@ -153,6 +153,53 @@ def check_toml(contents):
             yield (idx + 1, "found asterisk instead of minimum version number")
 
 
+def check_webidl_spec(contents):
+    # Sorted by this function (in pseudo-Rust). The idea is to group the same
+    # organization together.
+    # fn sort_standards(a: &Url, b: &Url) -> Ordering {
+    #     let a_domain = a.domain().split(".");
+    #     a_domain.pop();
+    #     a_domain.reverse();
+    #     let b_domain = b.domain().split(".");
+    #     b_domain.pop();
+    #     b_domain.reverse();
+    #     for i in a_domain.into_iter().zip(b_domain.into_iter()) {
+    #         match i.0.cmp(b.0) {
+    #             Less => return Less,
+    #             Greater => return Greater,
+    #             _ => (),
+    #         }
+    #     }
+    #     a_domain.path().cmp(b_domain.path())
+    # }
+    standards = [
+        "//w3c.github.io",
+        "//www.khronos.org/registry/webgl/specs",
+        "//developer.mozilla.org/en-US/docs/Mozilla/Tech/XUL/browser",
+        "//developer.mozilla.org/en-US/docs/Web/API",
+        "//dev.w3.org/2006/webapi",
+        "//dev.w3.org/csswg",
+        "//dev.w3.org/fxtf",
+        "//dvcs.w3.org/hg",
+        "//www.w3.org/TR",
+        "//dom.spec.whatwg.org",
+        "//domparsing.spec.whatwg.org",
+        "//encoding.spec.whatwg.org",
+        "//html.spec.whatwg.org",
+        "//url.spec.whatwg.org",
+        "//xhr.spec.whatwg.org",
+        "//www.whatwg.org/html",
+        "//www.whatwg.org/specs",
+        # Not a URL
+        "// This interface is entirely internal to Servo, and should not be" +
+        " accessible to\n// web pages."
+    ]
+    for i in standards:
+        if contents.find(i) != -1:
+            return True
+    return False
+
+
 def collect_errors_for_files(files_to_check, checking_functions):
     for file_name in files_to_check:
         with open(file_name, "r") as fp:
@@ -160,6 +207,9 @@ def collect_errors_for_files(files_to_check, checking_functions):
             if file_name.endswith(".toml"):
                 for error in check_toml(contents):
                     yield (file_name, error[0], error[1])
+            elif file_name.endswith(".webidl"):
+                if not check_webidl_spec(contents):
+                    yield (file_name, 0, "No specification link found.")
             else:
                 for check in checking_functions:
                     for error in check(contents):