Rename and conditionalize source for podspec

hermes.podspec

@@ -12,14 +12,16 @@ module HermesHelper
 end
 
 Pod::Spec.new do |spec|
-  spec.name        = "hermes"
+  spec.name        = "hermes-engine"
   spec.version     = "0.7.0"
   spec.summary     = "Hermes is a small and lightweight JavaScript engine optimized for running React Native."
   spec.description = "Hermes is a JavaScript engine optimized for fast start-up of React Native apps. It features ahead-of-time static optimization and compact bytecode."
   spec.homepage    = "https://hermesengine.dev"
   spec.license     = { type: "MIT", file: "LICENSE" }
   spec.author      = "Facebook"
-  spec.source      = { git: "https://github.com/facebook/hermes.git", tag: "v#{spec.version}" }
+  # This env var should be supplied with a CDN URL for hermes-engine-darwin.tgz on the Github releases before pod push.
+  # The podspec would be serialized to JSON and people will download prebuilt binaries instead of the source.
+  spec.source      = ENV['hermes-artifact-url'] ? ENV['hermes-artefict-url'] : { git: "https://github.com/facebook/hermes.git", tag: "v#{spec.version}" }
   spec.platforms   = { :osx => HermesHelper::OSX_DEPLOYMENT_TARGET, :ios => HermesHelper::IOS_DEPLOYMENT_TARGET }
 
   spec.preserve_paths      = ["destroot/bin/*"].concat(HermesHelper::BUILD_TYPE == :debug ? ["**/*.{h,c,cpp}"] : [])
@@ -31,31 +33,33 @@ Pod::Spec.new do |spec|
 
   spec.xcconfig            = { "CLANG_CXX_LANGUAGE_STANDARD" => "c++14", "CLANG_CXX_LIBRARY" => "compiler-default", "GCC_PREPROCESSOR_DEFINITIONS" => "HERMES_ENABLE_DEBUGGER=1" }
 
-  spec.prepare_command = <<-EOS
-    # When true, debug build will be used.
-    # See `build-apple-framework.sh` for details
-    DEBUG=#{HermesHelper::BUILD_TYPE == :debug}
-
-    # In a release package, there are no utilities and source files, we exit
-    # early as there is nothing to build 
-    if [ ! -f ./utils/build-apple-framework.sh ]; then
-      exit 0;
-    fi
-
-    # Source utilities into the scope
-    . ./utils/build-apple-framework.sh
-
-    # If universal framework for iOS does not exist, build one
-    if [ ! -d destroot/Library/Frameworks/iphoneos/hermes.framework ]; then
-      build_apple_framework "iphoneos" "armv7;armv7s;arm64" "#{HermesHelper::IOS_DEPLOYMENT_TARGET}"
-      build_apple_framework "iphonesimulator" "x86_64;i386" "#{HermesHelper::IOS_DEPLOYMENT_TARGET}"
-
-      create_universal_framework "iphoneos" "iphonesimulator"
-    fi
-
-    # If MacOS framework does not exist, build one
-    if [ ! -d destroot/Library/Frameworks/macosx/hermes.framework ]; then
-      build_apple_framework "macosx" "x86_64;arm64" "#{HermesHelper::OSX_DEPLOYMENT_TARGET}"
-    fi
-  EOS
+  unless ENV['hermes-artefact-url']
+    spec.prepare_command = <<-EOS
+      # When true, debug build will be used.
+      # See `build-apple-framework.sh` for details
+      DEBUG=#{HermesHelper::BUILD_TYPE == :debug}
+
+      # In a release package, there are no utilities and source files, we exit
+      # early as there is nothing to build 
+      if [ ! -f ./utils/build-apple-framework.sh ]; then
+        exit 0;
+      fi
+
+      # Source utilities into the scope
+      . ./utils/build-apple-framework.sh
+
+      # If universal framework for iOS does not exist, build one
+      if [ ! -d destroot/Library/Frameworks/iphoneos/hermes.framework ]; then
+        build_apple_framework "iphoneos" "armv7;armv7s;arm64" "#{HermesHelper::IOS_DEPLOYMENT_TARGET}"
+        build_apple_framework "iphonesimulator" "x86_64;i386" "#{HermesHelper::IOS_DEPLOYMENT_TARGET}"
+
+        create_universal_framework "iphoneos" "iphonesimulator"
+      fi
+
+      # If MacOS framework does not exist, build one
+      if [ ! -d destroot/Library/Frameworks/macosx/hermes.framework ]; then
+        build_apple_framework "macosx" "x86_64;arm64" "#{HermesHelper::OSX_DEPLOYMENT_TARGET}"
+      fi
+    EOS
+  end
 end