servo: Merge #13405 - Removed support for UTF-16 in TextEncoder (from ashrko619:textencoder-encoding); r=Ms2ger

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---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #13231  (github issue number if applicable).

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Source-Repo: https://github.com/servo/servo
Source-Revision: d03f0a20cc0f98ee55fbca65d71ff59026bee323

servo/components/script/dom/textencoder.rs

@@ -5,75 +5,54 @@
 use core::nonzero::NonZero;
 use dom::bindings::codegen::Bindings::TextEncoderBinding;
 use dom::bindings::codegen::Bindings::TextEncoderBinding::TextEncoderMethods;
-use dom::bindings::error::{Error, Fallible};
+use dom::bindings::error::Fallible;
 use dom::bindings::global::GlobalRef;
 use dom::bindings::js::Root;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::str::{DOMString, USVString};
 use encoding::EncoderTrap;
-use encoding::label::encoding_from_whatwg_label;
-use encoding::types::EncodingRef;
+use encoding::Encoding;
+use encoding::all::UTF_8;
 use js::jsapi::{JSContext, JSObject};
 use js::jsapi::{JS_GetUint8ArrayData, JS_NewUint8Array};
 use libc::uint8_t;
-use std::borrow::ToOwned;
 use std::ptr;
 
 #[dom_struct]
 pub struct TextEncoder {
     reflector_: Reflector,
-    #[ignore_heap_size_of = "Defined in rust-encoding"]
-    encoder: EncodingRef,
 }
 
 impl TextEncoder {
-    fn new_inherited(encoder: EncodingRef) -> TextEncoder {
+    fn new_inherited() -> TextEncoder {
         TextEncoder {
             reflector_: Reflector::new(),
-            encoder: encoder,
         }
     }
 
-    pub fn new(global: GlobalRef, encoder: EncodingRef) -> Root<TextEncoder> {
-        reflect_dom_object(box TextEncoder::new_inherited(encoder),
+    pub fn new(global: GlobalRef) -> Root<TextEncoder> {
+        reflect_dom_object(box TextEncoder::new_inherited(),
                            global,
                            TextEncoderBinding::Wrap)
     }
 
     // https://encoding.spec.whatwg.org/#dom-textencoder
-    pub fn Constructor(global: GlobalRef,
-                       label: DOMString) -> Fallible<Root<TextEncoder>> {
-        let encoding = match encoding_from_whatwg_label(&label) {
-            Some(enc) => enc,
-            None => {
-                debug!("Encoding Label Not Supported");
-                return Err(Error::Range("The given encoding is not supported.".to_owned()))
-            }
-        };
-
-        match encoding.name() {
-            "utf-8" | "utf-16be" | "utf-16le" => {
-                Ok(TextEncoder::new(global, encoding))
-            }
-            _ => {
-                debug!("Encoding Not UTF");
-                Err(Error::Range("The encoding must be utf-8, utf-16le, or utf-16be.".to_owned()))
-            }
-        }
+    pub fn Constructor(global: GlobalRef) -> Fallible<Root<TextEncoder>> {
+        Ok(TextEncoder::new(global))
     }
 }
 
 impl TextEncoderMethods for TextEncoder {
     // https://encoding.spec.whatwg.org/#dom-textencoder-encoding
     fn Encoding(&self) -> DOMString {
-        DOMString::from(self.encoder.name())
+        DOMString::from(UTF_8.name())
     }
 
     #[allow(unsafe_code)]
     // https://encoding.spec.whatwg.org/#dom-textencoder-encode
     fn Encode(&self, cx: *mut JSContext, input: USVString) -> NonZero<*mut JSObject> {
         unsafe {
-            let encoded = self.encoder.encode(&input.0, EncoderTrap::Strict).unwrap();
+            let encoded = UTF_8.encode(&input.0, EncoderTrap::Strict).unwrap();
             let length = encoded.len() as u32;
             rooted!(in(cx) let js_object = JS_NewUint8Array(cx, length));
             assert!(!js_object.is_null());

servo/components/script/dom/webidls/TextEncoder.webidl

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* https://encoding.spec.whatwg.org/#interface-textencoder */
-[Constructor(optional DOMString utfLabel = "utf-8"), Exposed=(Window,Worker)]
+[Constructor, Exposed=(Window,Worker)]
 interface TextEncoder {
    readonly attribute DOMString encoding;
    [NewObject]