Add optional WHATWG Streams polyfill

CMakeLists.txt

@@ -102,6 +102,7 @@ option(JSRUNTIMEHOST_POLYFILL_FILE "Include JsRuntimeHost Polyfill File and File
 option(JSRUNTIMEHOST_POLYFILL_PERFORMANCE "Include JsRuntimeHost Polyfill Performance." ON)
 option(JSRUNTIMEHOST_POLYFILL_TEXTDECODER "Include JsRuntimeHost Polyfill TextDecoder." ON)
 option(JSRUNTIMEHOST_POLYFILL_TEXTENCODER "Include JsRuntimeHost Polyfill TextEncoder." ON)
+option(JSRUNTIMEHOST_POLYFILL_STREAMS "Include JsRuntimeHost Polyfill Web Streams." ON)
 
 # Sanitizers
 option(ENABLE_SANITIZERS "Enable AddressSanitizer and UBSan" OFF)

Polyfills/CMakeLists.txt

@@ -44,4 +44,8 @@ endif()
 
 if(JSRUNTIMEHOST_POLYFILL_TEXTENCODER)
     add_subdirectory(TextEncoder)
-endif()
+endif()
+
+if(JSRUNTIMEHOST_POLYFILL_STREAMS)
+    add_subdirectory(Streams)
+endif()

Polyfills/Streams/CMakeLists.txt

@@ -0,0 +1,52 @@
+set(WEB_STREAMS_POLYFILL_FILE
+    "${CMAKE_CURRENT_SOURCE_DIR}/ThirdParty/web-streams-polyfill/ponyfill.es5.js")
+set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS
+    "${WEB_STREAMS_POLYFILL_FILE}")
+file(READ "${WEB_STREAMS_POLYFILL_FILE}" WEB_STREAMS_POLYFILL_SOURCE)
+# MSVC caps a single string literal at 16,380 bytes (C2026) and a concatenated one at 65,535, so
+# the bundle is emitted as consecutive raw-string parts of at most 16,000 bytes and joined back
+# into one array at compile time. Parts abut with no separator so the split stays byte-transparent
+# (a separator could land inside an identifier or string literal when the bundle is regenerated).
+string(LENGTH "${WEB_STREAMS_POLYFILL_SOURCE}" _streams_length)
+set(_streams_part_size 16000)
+set(_streams_offset 0)
+set(_streams_index 0)
+set(WEB_STREAMS_POLYFILL_PARTS "")
+set(WEB_STREAMS_POLYFILL_PART_NAMES "")
+while(_streams_offset LESS _streams_length)
+    math(EXPR _streams_index "${_streams_index} + 1")
+    math(EXPR _streams_remaining "${_streams_length} - ${_streams_offset}")
+    if(_streams_remaining LESS _streams_part_size)
+        set(_streams_take ${_streams_remaining})
+    else()
+        set(_streams_take ${_streams_part_size})
+    endif()
+    string(SUBSTRING "${WEB_STREAMS_POLYFILL_SOURCE}" ${_streams_offset} ${_streams_take} _streams_part)
+    string(APPEND WEB_STREAMS_POLYFILL_PARTS
+        "    inline constexpr char PonyfillPart${_streams_index}[] = R\"JSRHSTREAM(${_streams_part})JSRHSTREAM\";\n")
+    string(APPEND WEB_STREAMS_POLYFILL_PART_NAMES ", PonyfillPart${_streams_index}")
+    math(EXPR _streams_offset "${_streams_offset} + ${_streams_take}")
+endwhile()
+configure_file(
+    "Source/StreamsScripts.h.in"
+    "${CMAKE_CURRENT_BINARY_DIR}/Generated/StreamsScripts.h"
+    @ONLY)
+
+set(SOURCES
+    "Include/Babylon/Polyfills/Streams.h"
+    "Source/Streams.cpp"
+    "Source/StreamsScripts.h.in"
+    "ThirdParty/web-streams-polyfill/LICENSE"
+    "ThirdParty/web-streams-polyfill/ponyfill.es5.js")
+
+add_library(Streams ${SOURCES})
+warnings_as_errors(Streams)
+
+target_include_directories(Streams
+    PUBLIC "Include"
+    PRIVATE "${CMAKE_CURRENT_BINARY_DIR}/Generated")
+
+target_link_libraries(Streams PUBLIC JsRuntime)
+
+set_property(TARGET Streams PROPERTY FOLDER Polyfills)
+source_group(TREE ${CMAKE_CURRENT_SOURCE_DIR} FILES ${SOURCES})

Polyfills/Streams/Include/Babylon/Polyfills/Streams.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <Babylon/Api.h>
+#include <napi/env.h>
+
+namespace Babylon::Polyfills::Streams
+{
+    // Installs the WHATWG Streams constructors that are not already supplied
+    // by the JavaScript engine.
+    void BABYLON_API Initialize(Napi::Env env);
+}

Polyfills/Streams/README.md

@@ -0,0 +1,14 @@
+# Web Streams
+
+Installs the standard `ReadableStream`, `WritableStream`, `TransformStream`,
+reader, writer, controller, and queuing-strategy globals when the selected
+JavaScript engine does not provide them.
+
+The implementation is the ES5 ponyfill bundle from
+[`web-streams-polyfill` 4.3.0](https://github.com/MattiasBuelens/web-streams-polyfill/tree/add69059ed08eae6a18559aba49575a280d1529e),
+which is based on the WHATWG reference implementation. The vendored project
+tests this release against the Streams portion of WPT at revision
+[`c05b4473`](https://github.com/web-platform-tests/wpt/tree/c05b447326585237713013c66341eab2cdf967b6/streams).
+
+`Initialize` preserves any Streams constructors already supplied by the host
+engine and fills only missing globals.

Polyfills/Streams/Source/Streams.cpp

@@ -0,0 +1,53 @@
+#include <Babylon/Polyfills/Streams.h>
+
+#include "StreamsScripts.h"
+
+#include <array>
+#include <string_view>
+
+namespace Babylon::Polyfills::Streams
+{
+    void BABYLON_API Initialize(Napi::Env env)
+    {
+        Napi::HandleScope scope{env};
+        auto global = env.Global();
+
+        static constexpr std::array<std::string_view, 13> constructorNames{
+            "ReadableStream",
+            "ReadableStreamDefaultController",
+            "ReadableByteStreamController",
+            "ReadableStreamBYOBRequest",
+            "ReadableStreamDefaultReader",
+            "ReadableStreamBYOBReader",
+            "WritableStream",
+            "WritableStreamDefaultController",
+            "WritableStreamDefaultWriter",
+            "ByteLengthQueuingStrategy",
+            "CountQueuingStrategy",
+            "TransformStream",
+            "TransformStreamDefaultController",
+        };
+
+        bool needsPonyfill{};
+        for (const auto name : constructorNames)
+        {
+            const auto constructor = global.Get(name.data());
+            if (constructor.IsUndefined() || constructor.IsNull())
+            {
+                needsPonyfill = true;
+                break;
+            }
+        }
+
+        if (!needsPonyfill)
+        {
+            return;
+        }
+
+        const auto exports = Napi::Eval(env, Internal::StreamsScripts::Ponyfill.data(), "jsruntimehost://web-streams-polyfill.js").As<Napi::Object>();
+        for (const auto name : constructorNames)
+        {
+            global.Set(name.data(), exports.Get(name.data()));
+        }
+    }
+}

Polyfills/Streams/Source/StreamsScripts.h.in

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <array>
+#include <cstddef>
+
+namespace Babylon::Polyfills::Internal::StreamsScripts
+{
+    // The vendored bundle is split by CMake into PonyfillPart1..N raw-string literals of at most
+    // 16,000 bytes each (MSVC C2026) and joined below. The prologue and epilogue wrap it as a
+    // CommonJS module so its exports can be read back. Nothing is inserted between parts: a
+    // separator could divide an identifier or string literal when the bundle is regenerated.
+    inline constexpr char PonyfillPrologue[] = R"JSRHSTREAM(
+(function() {
+    var exports = {};
+    var module = { exports: exports };
+)JSRHSTREAM";
+
+@WEB_STREAMS_POLYFILL_PARTS@
+    inline constexpr char PonyfillEpilogue[] = R"JSRHSTREAM(
+    return module.exports;
+})()
+)JSRHSTREAM";
+
+    template<std::size_t... Sizes>
+    consteval auto Join(const char (&... parts)[Sizes])
+    {
+        std::array<char, (Sizes + ...) - sizeof...(Sizes) + 1> result{};
+        std::size_t offset{};
+        auto append = [&](const char* part, std::size_t size) {
+            for (std::size_t index{}; index + 1 < size; ++index)
+            {
+                result[offset++] = part[index];
+            }
+        };
+        (append(parts, Sizes), ...);
+        return result;
+    }
+
+    inline constexpr auto Ponyfill = Join(PonyfillPrologue@WEB_STREAMS_POLYFILL_PART_NAMES@, PonyfillEpilogue);
+}

Polyfills/Streams/ThirdParty/web-streams-polyfill/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2026 Mattias Buelens
+Copyright (c) 2016 Diwank Singh Tomer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Tests/UnitTests/CMakeLists.txt

@@ -30,6 +30,7 @@ set(SOURCES
     "Source/Tests.NodeApi.cpp"
     "Source/Tests.Scheduling.cpp"
     "Source/Tests.StandardStreamLogger.cpp"
+    "Source/Tests.Streams.cpp"
     "Source/Tests.TimeoutDispatcher.cpp")
 
 if(APPLE)
@@ -95,6 +96,7 @@ target_link_libraries(UnitTests
     PRIVATE Performance
     PRIVATE TextDecoder
     PRIVATE TextEncoder
+    PRIVATE Streams
     ${ADDITIONAL_LIBRARIES})
 
 # See https://gitlab.kitware.com/cmake/cmake/-/issues/23543

Tests/UnitTests/Source/Android/app/src/main/cpp/CMakeLists.txt

@@ -27,6 +27,7 @@ add_library(UnitTestsJNI SHARED
     ${UNIT_TESTS_DIR}/Source/Tests.NodeApi.cpp
     ${UNIT_TESTS_DIR}/Source/Tests.Scheduling.cpp
     ${UNIT_TESTS_DIR}/Source/Tests.StandardStreamLogger.cpp
+    ${UNIT_TESTS_DIR}/Source/Tests.Streams.cpp
     ${UNIT_TESTS_DIR}/Source/Tests.TimeoutDispatcher.cpp)
 
 if(NAPI_JAVASCRIPT_ENGINE STREQUAL "V8")
@@ -63,4 +64,5 @@ target_link_libraries(UnitTestsJNI
     PRIVATE File
     PRIVATE TextDecoder
     PRIVATE TextEncoder
-    PRIVATE Performance)
+    PRIVATE Performance
+    PRIVATE Streams)

Tests/UnitTests/Source/Scripts/tests.javaScript.all.ts

@@ -7,6 +7,7 @@ import "./tests.webSocket";
 import "./tests.url";
 import "./tests.urlSearchParams";
 import "./tests.console";
+import "./tests.streams";
 import "./tests.blob";
 import "./tests.nodeApi";
 import "./tests.performance";