Add Hermes CI coverage

.github/workflows/build-android.yml

@@ -26,12 +26,22 @@ jobs:
           distribution: temurin
           java-version: '17'
 
+      - name: Install Ninja (Hermes host-compiler bootstrap)
+        if: inputs.js-engine == 'Hermes'
+        run: |
+          if [ "${{ runner.os }}" = "Linux" ]; then
+            sudo apt-get update
+            sudo apt-get install -y ninja-build
+          elif [ "${{ runner.os }}" = "macOS" ] && ! command -v ninja >/dev/null 2>&1; then
+            brew install ninja
+          fi
+
       - name: Build Playground ${{ inputs.js-engine }}
         working-directory: Apps/Playground/Android
         run: |
           chmod +x gradlew
           ./gradlew assembleRelease \
-            -PJSEngine=${{ inputs.js-engine }} \
+            -PjsEngine=${{ inputs.js-engine }} \
             -PARM64Only \
             -PNDK_VERSION=${{ env.NDK_VERSION }} \
             -PSANITIZERS=OFF

.github/workflows/build-linux.yml

@@ -24,7 +24,7 @@ env:
 jobs:
   build:
     runs-on: ubuntu-latest
-    timeout-minutes: 30
+    timeout-minutes: ${{ inputs.js-engine == 'Hermes' && 60 || 30 }}
     env:
       CC: ${{ inputs.cc }}
       CXX: ${{ inputs.cxx }}
@@ -46,6 +46,7 @@ jobs:
             -D BX_CONFIG_DEBUG=ON \
             -D OpenGL_GL_PREFERENCE=GLVND \
             -D BABYLON_DEBUG_TRACE=ON \
+            ${{ inputs.js-engine == 'Hermes' && '-D HERMES_UNICODE_LITE=ON -D HERMES_ALLOW_BOOST_CONTEXT=0' || '' }} \
             -D ENABLE_SANITIZERS=${{ inputs.enable-sanitizers && 'ON' || 'OFF' }} .
           ninja -C build/Linux
 

.github/workflows/build-win32.yml

@@ -39,6 +39,9 @@ jobs:
           elif [ "${{ inputs.napi-type }}" = "V8" ]; then
             SUFFIX="_V8"
             JS_DEFINE="-DNAPI_JAVASCRIPT_ENGINE=V8"
+          elif [ "${{ inputs.napi-type }}" = "Hermes" ]; then
+            SUFFIX="_Hermes"
+            JS_DEFINE="-DNAPI_JAVASCRIPT_ENGINE=Hermes -DHERMES_ALLOW_BOOST_CONTEXT=0"
           fi
           echo "suffix=$SUFFIX" >> "$GITHUB_OUTPUT"
           echo "js_define=$JS_DEFINE" >> "$GITHUB_OUTPUT"

.github/workflows/ci.yml

@@ -64,6 +64,12 @@ jobs:
       platform: x64
       napi-type: V8
 
+  Win32_x64_Hermes_D3D11:
+    uses: ./.github/workflows/build-win32.yml
+    with:
+      platform: x64
+      napi-type: Hermes
+
   Win32_x64_D3D11_Sanitizers:
     uses: ./.github/workflows/build-win32.yml
     with:
@@ -104,6 +110,13 @@ jobs:
       cxx: clang++
       js-engine: JavaScriptCore
 
+  Ubuntu_Clang_Hermes:
+    uses: ./.github/workflows/build-linux.yml
+    with:
+      cc: clang
+      cxx: clang++
+      js-engine: Hermes
+
   Ubuntu_GCC_JSC:
     uses: ./.github/workflows/build-linux.yml
     with:
@@ -124,6 +137,12 @@ jobs:
       runs-on: ubuntu-latest
       js-engine: V8
 
+  Android_Ubuntu_Hermes:
+    uses: ./.github/workflows/build-android.yml
+    with:
+      runs-on: ubuntu-latest
+      js-engine: Hermes
+
   Android_MacOS_JSC:
     uses: ./.github/workflows/build-android.yml
     with:

Apps/ModuleLoadTest/Source/App.X11.cpp

@@ -56,6 +56,9 @@ namespace ModuleLoadTest
             "libexpat.so.1",
             "libgbm.so.1",
             "libgldispatch.so.0",
+            "libicudata.so.74",
+            "libicuuc.so.74",
+            "liblzma.so.5",
             "libpciaccess.so.0",
             "libsensors.so.5",
             "libtinfo.so.6",

Apps/Playground/Android/BabylonNative/build.gradle

@@ -18,6 +18,25 @@ if (project.hasProperty("GRAPHICS_API")) {
 
 def arcore_libpath = layout.buildDirectory.dir("arcore-native").get().asFile.absolutePath
 
+def cmakeArguments = [
+    "-DANDROID_STL=c++_shared",
+    "-DENABLE_PCH=OFF",
+    "-DGRAPHICS_API=${graphics_api}",
+    "-DARCORE_LIBPATH=${arcore_libpath}/jni",
+    "-DNAPI_JAVASCRIPT_ENGINE=${jsEngine}",
+    "-DBABYLON_NATIVE_BUILD_APPS=ON",
+    "-DBABYLON_DEBUG_TRACE=ON"
+]
+// Hermes for Android needs HOST hermesc/shermes (they emit bytecode at build
+// time and can't run as NDK-cross-compiled binaries). JsRuntimeHost's CMake
+// bootstraps these host compilers automatically when cross-compiling, so no
+// hand-off is normally required. This property is an optional manual override:
+// pass -PimportHostCompilers=<ImportHostCompilers.cmake> to reuse a prebuilt
+// host-compiler set and skip the in-CMake bootstrap.
+if (project.hasProperty("importHostCompilers")) {
+    cmakeArguments.add("-DIMPORT_HOST_COMPILERS=${project.property('importHostCompilers')}")
+}
+
 configurations { natives }
 
 android {
@@ -36,13 +55,7 @@ android {
         externalNativeBuild {
             cmake {
                 abiFilters "arm64-v8a", "armeabi-v7a", "x86", "x86_64"
-                arguments "-DANDROID_STL=c++_shared",
-                    "-DENABLE_PCH=OFF",
-                    "-DGRAPHICS_API=${graphics_api}",
-                    "-DARCORE_LIBPATH=${arcore_libpath}/jni",
-                    "-DNAPI_JAVASCRIPT_ENGINE=${jsEngine}",
-                    "-DBABYLON_NATIVE_BUILD_APPS=ON",
-                    "-DBABYLON_DEBUG_TRACE=ON"
+                arguments(*cmakeArguments)
                 cppFlags += ["-Wno-deprecated-literal-operator"]
             }
         }

Apps/Playground/Scripts/validation_native.js

@@ -81,6 +81,7 @@
     }
 
     const engine = new BABYLON.NativeEngine();
+    globalThis.engine = engine;
     engine.getCaps().parallelShaderCompile = undefined;
 
     // Broaden Babylon's default retry strategy for the test framework: in addition to
@@ -113,6 +114,7 @@
     }
 
     const canvas = window;
+    globalThis.canvas = canvas;
 
     // Random replacement
     let seed = 1;

CMakeLists.txt

@@ -53,8 +53,8 @@ FetchContent_Declare(ios-cmake
     GIT_TAG 4.5.0
     EXCLUDE_FROM_ALL)
 FetchContent_Declare(JsRuntimeHost
-    GIT_REPOSITORY https://github.com/BabylonJS/JsRuntimeHost.git
-    GIT_TAG 272f6a9f3de78f7c4cd8a838ae9655c81fc4881a)
+    GIT_REPOSITORY https://github.com/CedricGuillemet/JsRuntimeHost.git
+    GIT_TAG hermes-integration)
 FetchContent_Declare(metal-cpp
     GIT_REPOSITORY https://github.com/bkaradzic/metal-cpp.git
     GIT_TAG metal-cpp_26

Embedding/Source/Runtime.cpp

@@ -182,6 +182,13 @@ namespace Babylon::Embedding
 #endif
 
         m_appRuntime->Dispatch([implPtr = this, window](Napi::Env env) {
+            // 0. Install the ES2020 `globalThis` self-reference. V8/JSC/Chakra
+            //    provide it intrinsically, but the embedded Hermes runtime does
+            //    not, and Hermes evaluates eval()'d code as indirect (global
+            //    scope) eval -- so browser-style snippets can only reach host
+            //    state through properties of the global object.
+            env.Global().Set("globalThis", env.Global());
+
             // 1. Make the Device available to JS.
             implPtr->m_device->AddToJavaScript(env);
 
@@ -225,6 +232,10 @@ namespace Babylon::Embedding
 
 #if BABYLON_NATIVE_POLYFILL_WINDOW
             Babylon::Polyfills::Window::Initialize(env);
+            // Alias `canvas` to the global object so playground snippets that
+            // reference a bare `canvas` global resolve under Hermes indirect
+            // eval (mirrors the `window` polyfill).
+            env.Global().Set("canvas", env.Global());
 #endif
 
             Babylon::Polyfills::TextDecoder::Initialize(env);