LibWeb: Move extract_body() into Fetch

Userland/Libraries/LibWeb/Fetch/BodyInit.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2022, Kenneth Myhra <kennethmyhra@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/IDLAbstractOperations.h>
+#include <LibWeb/Fetch/BodyInit.h>
+#include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
+#include <LibWeb/HTML/Window.h>
+#include <LibWeb/URL/URLSearchParams.h>
+
+namespace Web::Fetch {
+
+// https://fetch.spec.whatwg.org/#concept-bodyinit-extract
+// FIXME: The parameter 'body_init' should be 'typedef (ReadableStream or XMLHttpRequestBodyInit) BodyInit'. For now we just let it be 'XMLHttpRequestBodyInit'.
+ErrorOr<Infrastructure::BodyWithType> extract_body(JS::Realm& realm, XMLHttpRequestBodyInit const& body_init)
+{
+    auto& window = verify_cast<HTML::Window>(realm.global_object());
+
+    // FIXME: 1. Let stream be object if object is a ReadableStream object. Otherwise, let stream be a new ReadableStream, and set up stream.
+    auto* stream = realm.heap().allocate<Streams::ReadableStream>(realm, window);
+    // FIXME: 2. Let action be null.
+    // 3. Let source be null.
+    Infrastructure::Body::SourceType source {};
+    // 4. Let length be null.
+    Optional<u64> length {};
+    // 5. Let type be null.
+    Optional<ByteBuffer> type {};
+
+    // 6. Switch on object.
+    // FIXME: Still need to support BufferSource and FormData
+    TRY(body_init.visit(
+        [&](JS::Handle<FileAPI::Blob> const& blob) -> ErrorOr<void> {
+            // FIXME: Set action to this step: read object.
+            // Set source to object.
+            source = blob;
+            // Set length to object’s size.
+            length = blob->size();
+            // If object’s type attribute is not the empty byte sequence, set type to its value.
+            if (!blob->type().is_empty())
+                type = blob->type().to_byte_buffer();
+            return {};
+        },
+        [&](JS::Handle<JS::Object> const& buffer_source) -> ErrorOr<void> {
+            // Set source to a copy of the bytes held by object.
+            source = TRY(Bindings::IDL::get_buffer_source_copy(*buffer_source.cell()));
+            return {};
+        },
+        [&](JS::Handle<URL::URLSearchParams> const& url_search_params) -> ErrorOr<void> {
+            // Set source to the result of running the application/x-www-form-urlencoded serializer with object’s list.
+            source = url_search_params->to_string().to_byte_buffer();
+            // Set type to `application/x-www-form-urlencoded;charset=UTF-8`.
+            type = TRY(ByteBuffer::copy("application/x-www-form-urlencoded;charset=UTF-8"sv.bytes()));
+            return {};
+        },
+        [&](String const& scalar_value_string) -> ErrorOr<void> {
+            // NOTE: AK::String is always UTF-8.
+            // Set source to the UTF-8 encoding of object.
+            source = scalar_value_string.to_byte_buffer();
+            // Set type to `text/plain;charset=UTF-8`.
+            type = TRY(ByteBuffer::copy("text/plain;charset=UTF-8"sv.bytes()));
+            return {};
+        }));
+
+    // FIXME: 7. If source is a byte sequence, then set action to a step that returns source and length to source’s length.
+    // FIXME: 8. If action is non-null, then run these steps in in parallel:
+
+    // 9. Let body be a body whose stream is stream, source is source, and length is length.
+    auto body = Infrastructure::Body { JS::make_handle(stream), move(source), move(length) };
+    // 10. Return (body, type).
+    return Infrastructure::BodyWithType { .body = move(body), .type = move(type) };
+}
+
+}