Fix detecting nested EE constants in RuboCop

The InjectEnterpriseEditionModule cop would not detect certain nested EE
constants such as `EE::Foo::Bar::Baz`. This could result in it not
enforcing `prepend` being placed on the last line. This commit fixes
this by just performing a string match on the line, instead of relying
on AST matching.

rubocop/cop/inject_enterprise_edition_module.rb

@@ -11,9 +11,13 @@ module RuboCop
 
       METHODS = Set.new(%i[include extend prepend]).freeze
 
-      def_node_matcher :ee_const?, <<~PATTERN
-        (const (const _ :EE) _)
-      PATTERN
+      def ee_const?(node)
+        line = node.location.expression.source_line
+
+        # We use `match?` here instead of RuboCop's AST matching, as this makes
+        # it far easier to handle nested constants such as `EE::Foo::Bar::Baz`.
+        line.match?(/(\s|\()(::)?EE::/)
+      end
 
       def on_send(node)
         return unless METHODS.include?(node.children[1])

spec/rubocop/cop/inject_enterprise_edition_module_spec.rb

@@ -19,6 +19,41 @@ describe RuboCop::Cop::InjectEnterpriseEditionModule do
     SOURCE
   end
 
+  it 'does not flag the use of `prepend EEFoo` in the middle of a file' do
+    expect_no_offenses(<<~SOURCE)
+    class Foo
+      prepend EEFoo
+    end
+    SOURCE
+  end
+
+  it 'flags the use of `prepend EE::Foo::Bar` in the middle of a file' do
+    expect_offense(<<~SOURCE)
+    class Foo
+      prepend EE::Foo::Bar
+      ^^^^^^^^^^^^^^^^^^^^ Injecting EE modules must be done on the last line of this file, outside of any class or module definitions
+    end
+    SOURCE
+  end
+
+  it 'flags the use of `prepend(EE::Foo::Bar)` in the middle of a file' do
+    expect_offense(<<~SOURCE)
+    class Foo
+      prepend(EE::Foo::Bar)
+      ^^^^^^^^^^^^^^^^^^^^^ Injecting EE modules must be done on the last line of this file, outside of any class or module definitions
+    end
+    SOURCE
+  end
+
+  it 'flags the use of `prepend EE::Foo::Bar::Baz` in the middle of a file' do
+    expect_offense(<<~SOURCE)
+    class Foo
+      prepend EE::Foo::Bar::Baz
+      ^^^^^^^^^^^^^^^^^^^^^^^^^ Injecting EE modules must be done on the last line of this file, outside of any class or module definitions
+    end
+    SOURCE
+  end
+
   it 'flags the use of `prepend ::EE` in the middle of a file' do
     expect_offense(<<~SOURCE)
     class Foo