Merge pull request #1616 from cloudflare/jsnell/fixup-text-warning

src/workerd/api/http.c++

@@ -643,7 +643,7 @@ jsg::Promise<kj::String> Body::text(jsg::Lock& js) {
       auto& context = IoContext::current();
       if (context.isInspectorEnabled()) {
         KJ_IF_SOME(type, headersRef.get(jsg::ByteString(kj::str("Content-Type")))) {
-          maybeWarnIfNotText(type);
+          maybeWarnIfNotText(js, type);
         }
       }
 

src/workerd/api/r2-bucket.c++

@@ -1023,7 +1023,7 @@ jsg::Promise<kj::String> R2Bucket::GetResult::text(jsg::Lock& js) {
     if (context.isInspectorEnabled()) {
       // httpMetadata can't be null because GetResult always populates it.
       KJ_IF_SOME(type, KJ_REQUIRE_NONNULL(httpMetadata).contentType) {
-        maybeWarnIfNotText(type);
+        maybeWarnIfNotText(js, type);
       }
     }
 

src/workerd/api/util.c++

@@ -225,20 +225,16 @@ kj::Maybe<jsg::V8Ref<v8::Object>> cloneRequestCf(
   return kj::none;
 }
 
-void maybeWarnIfNotText(kj::StringPtr str) {
+void maybeWarnIfNotText(jsg::Lock& js, kj::StringPtr str) {
+  KJ_IF_SOME(parsed, MimeType::tryParse(str)) {
+    if (MimeType::isText(parsed)) return;
+  }
   // A common mistake is to call .text() on non-text content, e.g. because you're implementing a
   // search-and-replace across your whole site and you forgot that it'll apply to images too.
   // When running in the fiddle, let's warn the developer if they do this.
-  if (!str.startsWith("text/") &&
-      !str.endsWith("charset=UTF-8") &&
-      !str.endsWith("charset=utf-8") &&
-      !str.endsWith("xml") &&
-      !str.endsWith("json") &&
-      !str.endsWith("javascript")) {
-    IoContext::current().logWarning(kj::str(
-        "Called .text() on an HTTP body which does not appear to be text. The body's "
-        "Content-Type is \"", str, "\". The result will probably be corrupted. Consider "
-        "checking the Content-Type header before interpreting entities as text."));
-  }
+  js.logWarning(kj::str(
+      "Called .text() on an HTTP body which does not appear to be text. The body's "
+      "Content-Type is \"", str, "\". The result will probably be corrupted. Consider "
+      "checking the Content-Type header before interpreting entities as text."));
 }
 }  // namespace workerd::api

src/workerd/api/util.h

@@ -101,6 +101,6 @@ double dateNow();
 
 // =======================================================================================
 
-void maybeWarnIfNotText(kj::StringPtr str);
+void maybeWarnIfNotText(jsg::Lock& js, kj::StringPtr str);
 
 }  // namespace workerd::api

src/workerd/util/mimetype-test.c++

@@ -401,6 +401,13 @@ KJ_TEST("WHATWG tests") {
   KJ_ASSERT(MimeType::isJavascript(MimeType::JAVASCRIPT));
   KJ_ASSERT(MimeType::isJavascript(MimeType::XJAVASCRIPT));
   KJ_ASSERT(MimeType::isJavascript(MimeType::TEXT_JAVASCRIPT));
+
+  KJ_ASSERT(MimeType::isText(MimeType::PLAINTEXT));
+  KJ_ASSERT(MimeType::isText(MimeType::JSON));
+  KJ_ASSERT(MimeType::isText(MimeType::JAVASCRIPT));
+  KJ_ASSERT(MimeType::isText(MimeType::XJAVASCRIPT));
+  KJ_ASSERT(MimeType::isText(
+      KJ_ASSERT_NONNULL(MimeType::tryParse("application/json; charset=\"utf-8\""))));
 }
 
 }  // namespace

src/workerd/util/mimetype.c++

@@ -332,6 +332,14 @@ const MimeType MimeType::MANIFEST_JSON = MimeType("application"_kj, "manifest+js
 const MimeType MimeType::VTT = MimeType("text"_kj, "vtt"_kj);
 const MimeType MimeType::EVENT_STREAM = MimeType("text"_kj, "event-stream"_kj);
 
+bool MimeType::isText(const MimeType& mimeType) {
+  auto type = mimeType.type();
+  return type == "text" ||
+      isXml(mimeType) ||
+      isJson(mimeType) ||
+      isJavascript(mimeType);
+}
+
 bool MimeType::isXml(const MimeType& mimeType) {
   auto type = mimeType.type();
   auto subtype = mimeType.subtype();

src/workerd/util/mimetype.h

@@ -76,6 +76,7 @@ class MimeType final {
   static bool isImage(const MimeType& mimeType);
   static bool isVideo(const MimeType& mimeType);
   static bool isAudio(const MimeType& mimeType);
+  static bool isText(const MimeType& mimeType);
 
   static const MimeType JSON;
   static const MimeType PLAINTEXT;