refactor(web): use encoding_rs for text encoding (#10844)

This commit removes all JS based text encoding / text decoding. Instead
encoding now happens in Rust via encoding_rs (already in tree). This
implementation retains stream support, but adds the last missing
encodings. We are incredibly close to 100% WPT on text encoding now.

This should reduce our baseline heap by quite a bit.

1 files changed, 4 insertions, 8 deletions

diff --git a/extensions/fetch/22_body.js b/extensions/fetch/22_body.js
index 8c93e0fcf..f0c7ac8bd 100644
--- a/extensions/fetch/22_body.js
+++ b/extensions/fetch/22_body.js
@@ -223,8 +223,6 @@
     return Object.defineProperties(prototype.prototype, mixin);
   }
 
-  const decoder = new TextDecoder();
-
   /**
    * https://fetch.spec.whatwg.org/#concept-body-package-data
    * @param {Uint8Array} bytes
@@ -263,14 +261,12 @@
         throw new TypeError("Missing content type");
       }
       case "JSON":
-        return JSON.parse(decoder.decode(bytes));
+        return JSON.parse(core.decode(bytes));
       case "text":
-        return decoder.decode(bytes);
+        return core.decode(bytes);
     }
   }
 
-  const encoder = new TextEncoder();
-
   /**
    * @param {BodyInit} object
    * @returns {{body: InnerBody, contentType: string | null}}
@@ -305,10 +301,10 @@
       length = res.body.byteLength;
       contentType = res.contentType;
     } else if (object instanceof URLSearchParams) {
-      source = encoder.encode(object.toString());
+      source = core.encode(object.toString());
       contentType = "application/x-www-form-urlencoded;charset=UTF-8";
     } else if (typeof object === "string") {
-      source = encoder.encode(object);
+      source = core.encode(object);
       contentType = "text/plain;charset=UTF-8";
     } else if (object instanceof ReadableStream) {
       stream = object;