Create Helper to read the package.json from Cocoapods

packages/react-native/scripts/cocoapods/__tests__/new_architecture-test.rb

@@ -8,10 +8,12 @@
 require_relative "./test_utils/InstallerMock.rb"
 require_relative "./test_utils/PodMock.rb"
 require_relative "./test_utils/SpecMock.rb"
+require_relative "./test_utils/FileMock.rb"
 
 class NewArchitectureTests < Test::Unit::TestCase
     def teardown
         Pod::UI.reset()
+        FileMock.reset()
     end
 
     # ============================= #
@@ -181,6 +183,119 @@ def test_installModulesDependencies_whenNewArchDisabledAndSearchPathsAndCompiler
             ]
         )
     end
+
+    # ========================== #
+    # Test - Is New Arch Enabled #
+    # ========================== #
+
+    def test_isNewArchEnabled_whenOnMainAndFlagTrue_returnTrue
+        version = '1000.0.0'
+        new_arch_enabled = true
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOnMainAndFlagFalse_returnFalse
+        version = '1000.0.0'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("0", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOnStableAndFlagTrue_returnTrue
+        version = '0.73.0'
+        new_arch_enabled = true
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOnStableAndFlagFalse_returnFalse
+        version = '0.73.0'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("0", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOn100AndFlagTrue_returnTrue
+        version = '1.0.0-prealpha.0'
+        new_arch_enabled = true
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOn100PrealphaWithDotsAndFlagFalse_returnTrue
+        version = '1.0.0-prealpha.0'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOn100PrealphaWithDashAndFlagFalse_returnTrue
+        version = '1.0.0-prealpha-0'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOn100PrealphaOnlyWordsAndFlagFalse_returnTrue
+        version = '1.0.0-prealpha0'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    def test_isNewArchEnabled_whenOnGreaterThan100AndFlagFalse_returnTrue
+        version = '3.2.1'
+        new_arch_enabled = false
+
+        isEnabled = NewArchitectureHelper.is_new_arch_enabled(new_arch_enabled, version)
+
+        assert_equal("1", isEnabled)
+    end
+
+    # =================================== #
+    # Test - Extract React Native Version #
+    # =================================== #
+    def test_extractReactNativeVersion_whenFileDoesNotExists_raiseError()
+        react_native_path = './node_modules/react-native/'
+
+        exception = assert_raise(RuntimeError) do
+            NewArchitectureHelper.extract_react_native_version(react_native_path, :file_manager => FileMock)
+        end
+
+        assert_equal("Couldn't find the React Native package.json file at ./node_modules/react-native/package.json", exception.message)
+    end
+
+    def test_extractReactNativeVersion_whenFileExists_returnTheRightVersion()
+        react_native_path = "./node_modules/react-native/"
+        full_path = File.join(react_native_path, "package.json")
+        json = "{\"version\": \"1.0.0-prealpha.0\"}"
+        FileMock.mocked_existing_files([full_path])
+        FileMock.files_to_read({
+            full_path => json
+        })
+
+        version = NewArchitectureHelper.extract_react_native_version(react_native_path, :file_manager => FileMock)
+
+        assert_equal("1.0.0-prealpha.0", version)
+    end
+
 end
 
 # ================ #

packages/react-native/scripts/cocoapods/new_architecture.rb

@@ -3,6 +3,8 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
+require 'json'
+
 class NewArchitectureHelper
     @@shared_flags = "-DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1"
 
@@ -158,4 +160,36 @@ def self.install_modules_dependencies(spec, new_arch_enabled, folly_version)
     def self.folly_compiler_flags
         return @@folly_compiler_flags
     end
+
+    def self.extract_react_native_version(react_native_path, file_manager: File, json_parser: JSON)
+        package_json_file = File.join(react_native_path, "package.json")
+        if !file_manager.exist?(package_json_file)
+            raise "Couldn't find the React Native package.json file at #{package_json_file}"
+        end
+        package = json_parser.parse(file_manager.read(package_json_file))
+        return package["version"]
+    end
+
+    def self.is_new_arch_enabled(new_arch_enabled, react_native_version)
+        # Regex that identify a version with the syntax `<major>.<minor>.<patch>[-<prerelease>[.-]k]
+        # where
+        # - major is a number
+        # - minor is a number
+        # - patch is a number
+        # - prerelease is a string (can include numbers)
+        # - k is a number
+        version_regex = /^(\d+)\.(\d+)\.(\d+)(?:-(\w+(?:[-.]\d+)?))?$/
+
+        if match_data = react_native_version.match(version_regex)
+
+            major = match_data[1].to_i
+
+            # We want to enforce the new architecture for 1.0.0 and greater,
+            # but not for 1000 as version 1000 is currently main.
+            if major > 0 && major < 1000
+                return "1"
+            end
+        end
+        return new_arch_enabled ? "1" : "0"
+    end
 end