fetch: implement new spec changes

lib/fetch/body.js

@@ -19,33 +19,45 @@ const { parseMIMEType, serializeAMimeType } = require('./dataURL')
 /** @type {globalThis['ReadableStream']} */
 let ReadableStream
 
-async function * blobGen (blob) {
-  yield * blob.stream()
-}
-
 // https://fetch.spec.whatwg.org/#concept-bodyinit-extract
 function extractBody (object, keepalive = false) {
   if (!ReadableStream) {
     ReadableStream = require('stream/web').ReadableStream
   }
 
-  // 1. Let stream be object if object is a ReadableStream object.
-  // Otherwise, let stream be a new ReadableStream, and set up stream.
+  // 1. Let stream be null.
   let stream = null
 
-  // 2. Let action be null.
+  // 2. If object is a ReadableStream object, then set stream to object.
+  if (object instanceof ReadableStream) {
+    stream = object
+  } else if (isBlobLike(object)) {
+    // 3. Otherwise, if object is a Blob object, set stream to the
+    //    result of running object’s get stream.
+    stream = object.stream()
+  }
+
+  // 4. Otherwise, set stream to a new ReadableStream object, and set
+  //    up stream.
+
+  // 5. Assert: stream is a ReadableStream object.
+
+  // TODO(@KhafraDev): setting stream to an empty stream here causes
+  // the process to unexpectedly exit. An error is likely being swallowed.
+
+  // 6. Let action be null.
   let action = null
 
-  // 3. Let source be null.
+  // 7. Let source be null.
   let source = null
 
-  // 4. Let length be null.
+  // 8. Let length be null.
   let length = null
 
-  // 5. Let Content-Type be null.
-  let contentType = null
+  // 9. Let type be null.
+  let type = null
 
-  // 6. Switch on object:
+  // 10. Switch on object:
   if (object == null) {
     // Note: The IDL processor cannot handle this situation. See
     // https://crbug.com/335871.
@@ -60,8 +72,8 @@ function extractBody (object, keepalive = false) {
     // Set source to the result of running the application/x-www-form-urlencoded serializer with object’s list.
     source = object.toString()
 
-    // Set Content-Type to `application/x-www-form-urlencoded;charset=UTF-8`.
-    contentType = 'application/x-www-form-urlencoded;charset=UTF-8'
+    // Set type to `application/x-www-form-urlencoded;charset=UTF-8`.
+    type = 'application/x-www-form-urlencoded;charset=UTF-8'
   } else if (isArrayBuffer(object)) {
     // BufferSource/ArrayBuffer
 
@@ -104,7 +116,7 @@ function extractBody (object, keepalive = false) {
               }\r\n\r\n`
           )
 
-          yield * blobGen(value)
+          yield * value.stream()
 
           yield enc.encode('\r\n')
         }
@@ -119,26 +131,23 @@ function extractBody (object, keepalive = false) {
     // Set length to unclear, see html/6424 for improving this.
     // TODO
 
-    // Set Content-Type to `multipart/form-data; boundary=`,
+    // Set type to `multipart/form-data; boundary=`,
     // followed by the multipart/form-data boundary string generated
     // by the multipart/form-data encoding algorithm.
-    contentType = 'multipart/form-data; boundary=' + boundary
+    type = 'multipart/form-data; boundary=' + boundary
   } else if (isBlobLike(object)) {
     // Blob
 
-    // Set action to this step: read object.
-    action = blobGen
-
     // Set source to object.
     source = object
 
     // Set length to object’s size.
     length = object.size
 
     // If object’s type attribute is not the empty byte sequence, set
-    // Content-Type to its value.
+    // type to its value.
     if (object.type) {
-      contentType = object.type
+      type = object.type
     }
   } else if (typeof object[Symbol.asyncIterator] === 'function') {
     // If keepalive is true, then throw a TypeError.
@@ -160,17 +169,17 @@ function extractBody (object, keepalive = false) {
     // TODO: scalar value string?
     // TODO: else?
     source = toUSVString(object)
-    contentType = 'text/plain;charset=UTF-8'
+    type = 'text/plain;charset=UTF-8'
   }
 
-  // 7. If source is a byte sequence, then set action to a
+  // 11. If source is a byte sequence, then set action to a
   // step that returns source and length to source’s length.
   // TODO: What is a "byte sequence?"
   if (typeof source === 'string' || util.isBuffer(source)) {
     length = Buffer.byteLength(source)
   }
 
-  // 8. If action is non-null, then run these steps in in parallel:
+  // 12. If action is non-null, then run these steps in in parallel:
   if (action != null) {
     // Run action.
     let iterator
@@ -226,12 +235,12 @@ function extractBody (object, keepalive = false) {
     })
   }
 
-  // 9. Let body be a body whose stream is stream, source is source,
+  // 13. Let body be a body whose stream is stream, source is source,
   // and length is length.
   const body = { stream, source, length }
 
-  // 10. Return body and Content-Type.
-  return [body, contentType]
+  // 14. Return (body, type).
+  return [body, type]
 }
 
 // https://fetch.spec.whatwg.org/#bodyinit-safely-extract

lib/fetch/index.js

@@ -39,7 +39,7 @@ const {
 } = require('./util')
 const { kState, kHeaders, kGuard, kRealm } = require('./symbols')
 const assert = require('assert')
-const { safelyExtractBody, extractBody } = require('./body')
+const { safelyExtractBody } = require('./body')
 const {
   redirectStatus,
   nullBodyStatus,
@@ -427,8 +427,8 @@ function fetching ({
     crossOriginIsolatedCapability
   }
 
-  // 7. If request’s body is a byte sequence, then set request’s body to the
-  // first return value of safely extracting request’s body.
+  // 7. If request’s body is a byte sequence, then set request’s body to
+  //    request’s body as a body.
   // NOTE: Since fetching is only called from fetch, body should already be
   // extracted.
   assert(!request.body || request.body.stream)
@@ -758,8 +758,7 @@ async function mainFetch (fetchParams, recursive = false) {
         return
       }
 
-      // 2. Set response’s body to the first return value of safely
-      // extracting bytes.
+      // 2. Set response’s body to bytes as a body.
       response.body = safelyExtractBody(bytes)[0]
 
       // 3. Run fetch finale given fetchParams and response.
@@ -787,7 +786,7 @@ async function schemeFetch (fetchParams) {
     case 'about:': {
       // If request’s current URL’s path is the string "blank", then return a new response
       // whose status message is `OK`, header list is « (`Content-Type`, `text/html;charset=utf-8`) »,
-      // and body is the empty byte sequence.
+      // and body is the empty byte sequence as a body.
 
       // Otherwise, return a network error.
       return makeNetworkError('about scheme is not supported')
@@ -809,27 +808,36 @@ async function schemeFetch (fetchParams) {
 
       const blob = resolveObjectURL(currentURL.toString())
 
-      //    2. If request’s method is not `GET` or blob is not a Blob object, then return a network error. [FILEAPI]
+      //    2. If request’s method is not `GET` or blob is not a Blob object, then return a network error.
       if (request.method !== 'GET' || !isBlobLike(blob)) {
         return makeNetworkError('invalid method')
       }
 
-      //    3. Let response be a new response whose status message is `OK`.
-      const response = makeResponse({ statusText: 'OK', urlList: [currentURL] })
+      //    3. Let bodyWithType be the result of safely extracting blobURLEntry’s object.
+      const bodyWithType = safelyExtractBody(blob)
 
-      //    4. Append (`Content-Length`, blob’s size attribute value) to response’s header list.
-      response.headersList.set('content-length', `${blob.size}`)
+      // 4. Let body be bodyWithType’s body.
+      const body = bodyWithType[0]
 
-      //    5. Append (`Content-Type`, blob’s type attribute value) to response’s header list.
-      response.headersList.set('content-type', blob.type)
+      // 5. Let length be body’s length, serialized and isomorphic encoded.
+      const length = `${body.length}`
 
-      //    6. Set response’s body to the result of performing the read operation on blob.
-      // TODO (fix): This needs to read?
-      response.body = extractBody(blob)[0]
+      // 6. Let type be bodyWithType’s type if it is non-null; otherwise the empty byte sequence.
+      const type = bodyWithType[1] ?? ''
 
-      //    7. Return response.
-      return response
+      // 7. Return a new response whose status message is `OK`, header list is
+      //    « (`Content-Length`, length), (`Content-Type`, type) », and body is body.
+      const response = makeResponse({
+        statusText: 'OK',
+        headersList: [
+          ['content-length', length],
+          ['content-type', type]
+        ]
+      })
+
+      response.body = body
 
+      return response
       // 2. If aborted, then return the appropriate network error for fetchParams.
       // TODO
     }
@@ -850,13 +858,13 @@ async function schemeFetch (fetchParams) {
 
       // 4. Return a response whose status message is `OK`,
       //    header list is « (`Content-Type`, mimeType) »,
-      //    and body is dataURLStruct’s body.
+      //    and body is dataURLStruct’s body as a body.
       return makeResponse({
         statusText: 'OK',
         headersList: [
           ['content-type', mimeType]
         ],
-        body: extractBody(dataURLStruct.body)[0]
+        body: safelyExtractBody(dataURLStruct.body)[0]
       })
     }
     case 'file:': {