feat(ext/web): implement static Response.json (#14566)

This commit adds support for the static `Response.json` method.

ext/fetch/23_response.js

@@ -15,7 +15,8 @@
   const { isProxy } = Deno.core;
   const webidl = window.__bootstrap.webidl;
   const consoleInternal = window.__bootstrap.console;
-  const { HTTP_TAB_OR_SPACE, regexMatcher } = window.__bootstrap.infra;
+  const { HTTP_TAB_OR_SPACE, regexMatcher, serializeJSValueToJSONString } =
+    window.__bootstrap.infra;
   const { extractBody, mixinBody } = window.__bootstrap.fetchBody;
   const { getLocationHref } = window.__bootstrap.location;
   const { extractMimeType } = window.__bootstrap.mimesniff;
@@ -157,6 +158,56 @@
     return resp;
   }
 
+  /**
+   * https://fetch.spec.whatwg.org#initialize-a-response
+   * @param {Response} response
+   * @param {ResponseInit} init
+   * @param {{ body: __bootstrap.fetchBody.InnerBody, contentType: string | null } | null} bodyWithType
+   */
+  function initializeAResponse(response, init, bodyWithType) {
+    // 1.
+    if ((init.status < 200 || init.status > 599) && init.status != 101) {
+      throw new RangeError(
+        `The status provided (${init.status}) is not equal to 101 and outside the range [200, 599].`,
+      );
+    }
+
+    // 2.
+    if (
+      init.statusText &&
+      !RegExpPrototypeTest(REASON_PHRASE_RE, init.statusText)
+    ) {
+      throw new TypeError("Status text is not valid.");
+    }
+
+    // 3.
+    response[_response].status = init.status;
+
+    // 4.
+    response[_response].statusMessage = init.statusText;
+
+    // 5.
+    /** @type {__bootstrap.headers.Headers} */
+    const headers = response[_headers];
+    if (init.headers) {
+      fillHeaders(headers, init.headers);
+    }
+
+    // 6.
+    if (bodyWithType !== null) {
+      if (nullBodyStatus(response[_response].status)) {
+        throw new TypeError(
+          "Response with null body status cannot have body",
+        );
+      }
+      const { body, contentType } = bodyWithType;
+      response[_response].body = body;
+      if (contentType !== null && !headers.has("content-type")) {
+        headers.append("Content-Type", contentType);
+      }
+    }
+  }
+
   class Response {
     get [_mimeType]() {
       const values = getDecodeSplitHeader(
@@ -217,6 +268,32 @@
       return response;
     }
 
+    /**
+     * @param {any} data
+     * @param {ResponseInit} init
+     * @returns {Response}
+     */
+    static json(data, init = {}) {
+      const prefix = "Failed to call 'Response.json'";
+      data = webidl.converters.any(data);
+      init = webidl.converters["ResponseInit_fast"](init, {
+        prefix,
+        context: "Argument 2",
+      });
+
+      const str = serializeJSValueToJSONString(data);
+      const res = extractBody(str);
+      res.contentType = "application/json";
+      const response = webidl.createBranded(Response);
+      response[_response] = newInnerResponse();
+      response[_headers] = headersFromHeaderList(
+        response[_response].headerList,
+        "response",
+      );
+      initializeAResponse(response, init, res);
+      return response;
+    }
+
     /**
      * @param {BodyInit | null} body
      * @param {ResponseInit} init
@@ -232,40 +309,18 @@
         context: "Argument 2",
       });
 
-      if ((init.status < 200 || init.status > 599) && init.status != 101) {
-        throw new RangeError(
-          `The status provided (${init.status}) is not equal to 101 and outside the range [200, 599].`,
-        );
-      }
-
-      if (
-        init.statusText &&
-        !RegExpPrototypeTest(REASON_PHRASE_RE, init.statusText)
-      ) {
-        throw new TypeError("Status text is not valid.");
-      }
+      this[_response] = newInnerResponse();
+      this[_headers] = headersFromHeaderList(
+        this[_response].headerList,
+        "response",
+      );
 
-      this[webidl.brand] = webidl.brand;
-      const response = newInnerResponse(init.status, init.statusText);
-      /** @type {InnerResponse} */
-      this[_response] = response;
-      /** @type {Headers} */
-      this[_headers] = headersFromHeaderList(response.headerList, "response");
-      if (init.headers) {
-        fillHeaders(this[_headers], init.headers);
-      }
+      let bodyWithType = null;
       if (body !== null) {
-        if (nullBodyStatus(response.status)) {
-          throw new TypeError(
-            "Response with null body status cannot have body",
-          );
-        }
-        const res = extractBody(body);
-        response.body = res.body;
-        if (res.contentType !== null && !this[_headers].has("content-type")) {
-          this[_headers].append("Content-Type", res.contentType);
-        }
+        bodyWithType = extractBody(body);
       }
+      initializeAResponse(this, init, bodyWithType);
+      this[webidl.brand] = webidl.brand;
     }
 
     /**

ext/web/00_infra.js

@@ -11,23 +11,24 @@
 ((window) => {
   const core = Deno.core;
   const {
-    Error,
-    RegExp,
+    ArrayPrototypeJoin,
     ArrayPrototypeMap,
-    StringPrototypeCharCodeAt,
+    Error,
+    JSONStringify,
     NumberPrototypeToString,
-    StringPrototypePadStart,
-    TypeError,
-    ArrayPrototypeJoin,
+    RegExp,
     SafeArrayIterator,
+    String,
     StringPrototypeCharAt,
+    StringPrototypeCharCodeAt,
     StringPrototypeMatch,
-    StringPrototypeSlice,
-    String,
+    StringPrototypePadStart,
     StringPrototypeReplace,
-    StringPrototypeToUpperCase,
-    StringPrototypeToLowerCase,
+    StringPrototypeSlice,
     StringPrototypeSubstring,
+    StringPrototypeToLowerCase,
+    StringPrototypeToUpperCase,
+    TypeError,
   } = window.__bootstrap.primordials;
 
   const ASCII_DIGIT = ["\u0030-\u0039"];
@@ -294,6 +295,18 @@
     }
   }
 
+  /**
+   * @param {unknown} value
+   * @returns {string}
+   */
+  function serializeJSValueToJSONString(value) {
+    const result = JSONStringify(value);
+    if (result === undefined) {
+      throw new TypeError("Value is not JSON serializable.");
+    }
+    return result;
+  }
+
   window.__bootstrap.infra = {
     collectSequenceOfCodepoints,
     ASCII_DIGIT,
@@ -320,5 +333,6 @@
     forgivingBase64Decode,
     AssertionError,
     assert,
+    serializeJSValueToJSONString,
   };
 })(globalThis);

ext/web/internal.d.ts

@@ -45,6 +45,7 @@ declare namespace globalThis {
       };
       forgivingBase64Encode(data: Uint8Array): string;
       forgivingBase64Decode(data: string): Uint8Array;
+      serializeJSValueToJSONString(value: unknown): string;
     };
 
     declare var domException: {

tools/wpt/expectation.json

@@ -3215,7 +3215,9 @@
         "response-consume-stream.any.html": true,
         "response-consume-stream.any.worker.html": true,
         "response-init-contenttype.any.html": true,
-        "response-init-contenttype.any.worker.html": true
+        "response-init-contenttype.any.worker.html": true,
+        "response-static-json.any.html": true,
+        "response-static-json.any.worker.html": true
       },
       "body": {
         "formdata.any.html": [