mimesniff: fix many broken tests

lib/fetch/dataURL.js

@@ -42,14 +42,12 @@ function dataURLProcessor (dataURL) {
 
   // 6. Strip leading and trailing ASCII whitespace
   // from mimeType.
-  // Note: This will only remove U+0020 SPACE code
-  // points, if any.
   // Undici implementation note: we need to store the
   // length because if the mimetype has spaces removed,
   // the wrong amount will be sliced from the input in
   // step #9
   const mimeTypeLength = mimeType.length
-  mimeType = mimeType.replace(/^(\u0020)+|(\u0020)+$/g, '')
+  mimeType = removeASCIIWhitespace(mimeType, true, true)
 
   // 7. If position is past the end of input, then
   // return failure
@@ -286,17 +284,20 @@ function parseMIMEType (input) {
     return 'failure'
   }
 
+  const typeLowercase = type.toLowerCase()
+  const subtypeLowercase = subtype.toLowerCase()
+
   // 10. Let mimeType be a new MIME type record whose type
   // is type, in ASCII lowercase, and subtype is subtype,
   // in ASCII lowercase.
   // https://mimesniff.spec.whatwg.org/#mime-type
   const mimeType = {
-    type: type.toLowerCase(),
-    subtype: subtype.toLowerCase(),
+    type: typeLowercase,
+    subtype: subtypeLowercase,
     /** @type {Map<string, string>} */
     parameters: new Map(),
     // https://mimesniff.spec.whatwg.org/#mime-type-essence
-    essence: `${type}/${subtype}`
+    essence: `${typeLowercase}/${subtypeLowercase}`
   }
 
   // 11. While position is not past the end of input:
@@ -391,7 +392,7 @@ function parseMIMEType (input) {
     if (
       parameterName.length !== 0 &&
       HTTP_TOKEN_CODEPOINTS.test(parameterName) &&
-      HTTP_QUOTED_STRING_TOKENS.test(parameterValue) &&
+      (parameterValue.length === 0 || HTTP_QUOTED_STRING_TOKENS.test(parameterValue)) &&
       !mimeType.parameters.has(parameterName)
     ) {
       mimeType.parameters.set(parameterName, parameterValue)
@@ -591,6 +592,32 @@ function removeHTTPWhitespace (str, leading = true, trailing = true) {
   return str.slice(lead, trail + 1)
 }
 
+/**
+ * @see https://infra.spec.whatwg.org/#ascii-whitespace
+ * @param {string} char
+ */
+function isASCIIWhitespace (char) {
+  return char === '\r' || char === '\n' || char === '\t' || char === '\f' || char === ' '
+}
+
+/**
+ * @see https://infra.spec.whatwg.org/#strip-leading-and-trailing-ascii-whitespace
+ */
+function removeASCIIWhitespace (str, leading = true, trailing = true) {
+  let lead = 0
+  let trail = str.length - 1
+
+  if (leading) {
+    for (; lead < str.length && isASCIIWhitespace(str[lead]); lead++);
+  }
+
+  if (trailing) {
+    for (; trail > 0 && isASCIIWhitespace(str[trail]); trail--);
+  }
+
+  return str.slice(lead, trail + 1)
+}
+
 module.exports = {
   dataURLProcessor,
   URLSerializer,

lib/fetch/response.js

@@ -467,7 +467,7 @@ function initializeResponse (response, init, body) {
 
   // 5. If init["headers"] exists, then fill response’s headers with init["headers"].
   if ('headers' in init && init.headers != null) {
-    fill(response[kState].headersList, init.headers)
+    fill(response[kHeaders], init.headers)
   }
 
   // 6. If body was given, then: