fix: add cocoapods requirement (react-native-community#867)

* Add cocoapods requirement

As file is using `Pod`, cocoapods should be imported.

* Install cocoapods prior testing

* Drop mocking cocoapods

* Update tests with last changes

.circleci/config.yml

@@ -36,6 +36,13 @@ commands:
           root: .
           paths:
             - .
+
+  install-cocoapods:
+    steps:
+      - attach_workspace:
+           at: ~/react-native-cli
+      - run: gem install cocoapods
+
   run-lint:
     steps:
       - attach_workspace:
@@ -72,6 +79,7 @@ jobs:
   cocoa-pods:
     executor: noderuby
     steps:
+      - install-cocoapods
       - run-cocoa-pods-tests
   unit-tests:
     executor: node8

packages/platform-ios/native_modules.rb

@@ -4,6 +4,7 @@
 # imports those into your current target.
 #
 require 'pathname'
+require 'cocoapods'
 
 def use_native_modules!(config = nil)
   if (config.is_a? String)
@@ -106,27 +107,6 @@ def use_native_modules!(config = nil)
   require "minitest/spec"
   require "minitest/autorun"
 
-  # Define this here, because we’re not actually loading this code.
-  module Pod
-    class Specification
-    end
-
-    module UI
-    end
-  end
-
-  # CocoaPods loads ActiveSupport, but we’re not doing that here just for the test.
-  class Array
-    def to_sentence
-      size == 1 ? self[0] : "#{self[0..-2].join(", ")}, and #{self[-1]}"
-    end
-  end
-  class String
-    def pluralize(count)
-      count == 1 ? self : "#{self}s"
-    end
-  end
-
   describe "use_native_modules!" do
     before do
       @script_phase = {
@@ -238,7 +218,7 @@ def pluralize(count)
       })
       @printed_messages.must_equal [
         "Detected React Native module pod for ios-dep",
-        "Detected React Native module pods for ios-dep, and ios-dep"
+        "Detected React Native module pods for ios-dep and ios-dep"
       ]
     end