Move Hermes setup in a dedicated ruby file (#34100)

Summary:
Pull Request resolved: #34100

This Diff continue the effort of refactor and test the cocoapods script, moving hermes setup in a dedicated `hermes.rb` file and adding some tests on the logic of the hermes handling.

## Changelog
[iOS][Changed] - move and test Hermes setup from react_native_pods script into a dedicated file

Reviewed By: cortinico

Differential Revision: D37522432

fbshipit-source-id: 91112476aac576a30110e5dcd4e46fa12241962a

scripts/cocoapods/__tests__/hermes-test.rb

@@ -0,0 +1,85 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+require "test/unit"
+require_relative "../hermes.rb"
+require_relative "./test_utils/podSpy.rb"
+require_relative "./test_utils/PodMock.rb"
+require_relative "./test_utils/Open3Mock.rb"
+
+class HermesTests < Test::Unit::TestCase
+
+    :prefix
+
+    def setup
+        @prefix = "../.."
+    end
+
+    def teardown
+        Open3.reset()
+        Pod::Config.reset()
+        Pod::UI.reset()
+        podSpy_cleanUp()
+    end
+
+    def test_installHermesIfEnabled_whenHermesIsDisabled_doesNothing
+        # Arrange
+
+        # Act
+        install_hermes_if_enabled(false, @prefix)
+
+        # Assert
+        assert_equal($podInvocationCount, 0)
+        assert_equal($podInvocation, {})
+        assert_equal(Pod::UI.collected_infoes, [])
+        assert_equal(Open3.collected_commands, [])
+        assert_equal(Open3.collected_dirs, [])
+    end
+
+    def test_installHermesIfEnabled_whenHermesIsEnabledAndHermesScriptFails_abort
+        # Arrange
+        Pod::Config.instance.installation_root.set_installation_root("Pods/")
+        Open3.set_returned_status(1)
+        Open3.set_returned_text("This test\nshould fail")
+
+        # Act
+        assert_raises {
+            install_hermes_if_enabled(true, @prefix)
+        }
+
+        # Assert
+        assert_equal(Open3.collected_commands, ["node scripts/hermes/prepare-hermes-for-build"])
+        assert_equal(Open3.collected_dirs, ["Pods/../.."])
+        assert_equal(Pod::UI.collected_infoes, ["This test", "should fail"])
+        assert_equal($podInvocationCount, 0)
+        assert_equal($podInvocation, {})
+    end
+
+    def test_installHermesIfEnabled_whenHermesIsEnabledAndHermesScriptSucceeds_installsPods
+        # Arrange
+        Pod::Config.instance.installation_root.set_installation_root("Pods/")
+        Open3.set_returned_status(0)
+        Open3.set_returned_text("This is\nthe text\nreturned by\nprepare-hermes-for-build")
+
+        # Act
+        install_hermes_if_enabled(true, @prefix)
+
+        # Assert
+        assert_equal(Open3.collected_commands, ["node scripts/hermes/prepare-hermes-for-build"])
+        assert_equal(Open3.collected_dirs, ["Pods/../.."])
+        assert_equal(Pod::UI.collected_infoes, [
+            "This is",
+            "the text",
+            "returned by",
+            "prepare-hermes-for-build",
+        ])
+        assert_equal($podInvocationCount, 3)
+        assert_equal($podInvocation["React-hermes"][:path], "../../ReactCommon/hermes")
+        assert_equal($podInvocation["libevent"][:version], "~> 2.1.12")
+        assert_equal($podInvocation["hermes-engine"][:podspec], "../../sdks/hermes/hermes-engine.podspec")
+    end
+
+
+end

scripts/cocoapods/__tests__/test_utils/Open3Mock.rb

@@ -0,0 +1,43 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+class Open3
+    @@collected_commands = []
+    @@collected_dirs = []
+
+    @@returned_text = ""
+    @@returned_status = 0
+
+    def self.capture2e(command, chdir: ".")
+        @@collected_commands.push(command)
+        @@collected_dirs.push(chdir)
+
+        return [*@@returned_text, @@returned_status]
+    end
+
+    def self.collected_commands
+        return @@collected_commands
+    end
+
+    def self.collected_dirs
+        return @@collected_dirs
+    end
+
+    def self.set_returned_text(text)
+        @@returned_text = text
+    end
+
+    def self.set_returned_status(status)
+        @@returned_status = status
+    end
+
+    def self.reset()
+        @@collected_commands = []
+        @@collected_dirs = []
+
+        @@returned_text = ""
+        @@returned_status = 0
+    end
+end

scripts/cocoapods/__tests__/test_utils/PodMock.rb

@@ -25,21 +25,41 @@ def self.reset()
     class InstallationRootMock
 
         attr_accessor :relative_path_from
+        attr_accessor :installation_root
+
         attr_reader :relative_path_from_invocation_count
+        attr_reader :installation_root_invocation_count
 
         def initialize()
             @relative_path_from = ""
+            @installation_root = ""
             @relative_path_from_invocation_count = 0
+            @installation_root_invocation_count = 0
         end
 
         def relative_path_from(path)
             @relative_path_from_invocation_count += 1
             return @relative_path_from
         end
+
+        def installation_root(root)
+            @installation_root_invocation_count += 1
+            return @installation_root
+        end
+
+        def set_installation_root(root)
+            @installation_root = root
+        end
+
+        def join(path)
+            return @installation_root + path
+        end
+
     end
 
     class UI
 
+        @@collected_infoes = []
         @@collected_messages = []
         @@collected_warns = []
 
@@ -51,6 +71,10 @@ def self.warn(warn)
             @@collected_warns.push(warn)
         end
 
+        def self.info(info)
+            @@collected_infoes.push(info)
+        end
+
         def self.collected_messages()
             return @@collected_messages
         end
@@ -59,9 +83,14 @@ def self.collected_warns()
             return @@collected_warns
         end
 
+        def self.collected_infoes()
+            return @@collected_infoes
+        end
+
         def self.reset()
             @@collected_messages = []
             @@collected_warns = []
+            @@collected_infoes = []
         end
     end
 

scripts/cocoapods/hermes.rb

@@ -0,0 +1,20 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+def install_hermes_if_enabled(hermes_enabled, react_native_path)
+    unless hermes_enabled
+        return
+    end
+
+    prepare_hermes = 'node scripts/hermes/prepare-hermes-for-build'
+    react_native_dir = Pod::Config.instance.installation_root.join(react_native_path)
+    prep_output, prep_status = Open3.capture2e(prepare_hermes, :chdir => react_native_dir)
+    prep_output.split("\n").each { |line| Pod::UI.info line }
+    abort unless prep_status == 0
+
+    pod 'React-hermes', :path => "#{react_native_path}/ReactCommon/hermes"
+    pod 'libevent', '~> 2.1.12'
+    pod 'hermes-engine', :podspec => "#{react_native_path}/sdks/hermes/hermes-engine.podspec"
+end

scripts/react_native_pods.rb

@@ -7,6 +7,7 @@
 require 'open3'
 require 'pathname'
 require_relative './react_native_pods_utils/script_phases.rb'
+require_relative './cocoapods/hermes.rb'
 require_relative './cocoapods/flipper.rb'
 require_relative './cocoapods/fabric.rb'
 require_relative './cocoapods/codegen.rb'
@@ -101,17 +102,7 @@ def use_react_native! (options={})
     setup_fabric!(prefix)
   end
 
-  if hermes_enabled
-    prepare_hermes = 'node scripts/hermes/prepare-hermes-for-build'
-    react_native_dir = Pod::Config.instance.installation_root.join(prefix)
-    prep_output, prep_status = Open3.capture2e(prepare_hermes, :chdir => react_native_dir)
-    prep_output.split("\n").each { |line| Pod::UI.info line }
-    abort unless prep_status == 0
-
-    pod 'React-hermes', :path => "#{prefix}/ReactCommon/hermes"
-    pod 'libevent', '~> 2.1.12'
-    pod 'hermes-engine', :podspec => "#{prefix}/sdks/hermes/hermes-engine.podspec"
-  end
+  install_hermes_if_enabled(hermes_enabled, prefix)
 
   # CocoaPods `configurations` option ensures that the target is copied only for the specified configurations,
   # but those dependencies are still built.