move #called_externally to database_cleaner/deprecation, and test.

lib/database_cleaner/base.rb

@@ -87,14 +87,14 @@ def clean_with!
     # TODO privatize the following methods in 2.0
 
     def strategy_db=(desired_db)
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner[...].strategy_db=` is deprecated, and will be removed in database_cleaner 2.0. Use `DatabaseCleaner[...].db=` instead."
       end
       set_strategy_db(strategy, desired_db)
     end
 
     def set_strategy_db(strategy, desired_db)
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner[...].set_strategy_db=` is deprecated, and will be removed in database_cleaner 2.0. Use `DatabaseCleaner[...].db=` instead."
       end
       if strategy.respond_to? :db=
@@ -105,7 +105,7 @@ def set_strategy_db(strategy, desired_db)
     end
 
     def create_strategy(*args)
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner[...].create_strategy` is deprecated, and will be removed in database_cleaner 2.0. Use `DatabaseCleaner[...].strategy=` instead."
       end
       strategy, *strategy_args = args
@@ -149,9 +149,5 @@ def require_orm_strategy(orm, strategy)
     rescue LoadError
       raise UnknownStrategySpecified, "The '#{strategy}' strategy does not exist for the #{orm} ORM!  Available strategies: #{orm_module.available_strategies.join(', ')}"
     end
-
-    def called_externally?(caller)
-      __FILE__ != caller.first.split(":").first
-    end
   end
 end

lib/database_cleaner/configuration.rb

@@ -109,7 +109,7 @@ def init_cleaners
     end
 
     def connections
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner.connections` is deprecated, and will be removed in database_cleaner 2.0. Use `DatabaseCleaner.cleaners`, instead."
       end
       add_cleaner(:autodetect) if @cleaners.none?
@@ -119,23 +119,17 @@ def connections
     # TODO privatize the following methods in 2.0
 
     def add_cleaner(orm, opts = {})
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner.add_cleaner` is deprecated, and will be removed in database_cleaner 2.0. Use `DatabaseCleaner.[]`, instead."
       end
       @cleaners.add_cleaner(orm, opts = {})
     end
 
     def remove_duplicates
-      if called_externally?(caller)
+      if DatabaseCleaner.called_externally?(__FILE__, caller)
         DatabaseCleaner.deprecate "Calling `DatabaseCleaner.remove_duplicates` is deprecated, and will be removed in database_cleaner 2.0 with no replacement."
       end
       @cleaners.remove_duplicates
     end
-
-    private
-
-    def called_externally?(caller)
-      __FILE__ != caller.first.split(":").first
-    end
   end
 end

lib/database_cleaner/deprecation.rb

@@ -6,6 +6,11 @@ def deprecate message
   end
   module_function :deprecate
 
+  def called_externally?(file, caller)
+    file != caller.first.split(":").first
+  end
+  module_function :called_externally?
+
   class Deprecator
     def initialize
       @methods_already_warned = {}

spec/database_cleaner/deprecation_spec.rb

@@ -0,0 +1,26 @@
+require "database_cleaner/deprecation"
+
+RSpec.describe DatabaseCleaner do
+  describe ".called_externally?" do
+    let(:path) { "/home/DatabaseCleaner/database_cleaner/spec/database_cleaner/deprecation_spec.rb" }
+
+    it "returns false if the supplied file is the first file in the backtrace" do
+      backtrace = [
+        "/home/DatabaseCleaner/database_cleaner/spec/database_cleaner/deprecation_spec.rb:9 in `it'",
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1954:in `load'",
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1954:in `load_spec_file_handling_errors'",
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1496:in `block in load_spec_files'",
+      ]
+      expect(DatabaseCleaner.called_externally?(path, backtrace)).to eq false
+    end
+
+    it "returns true if the supplied file is not the first file in the backtrace" do
+      backtrace = [
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1954:in `load'",
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1954:in `load_spec_file_handling_errors'",
+        "/home/DatabaseCleaner/lib/rspec/core/configuration.rb:1496:in `block in load_spec_files'",
+      ]
+      expect(DatabaseCleaner.called_externally?(path, backtrace)).to eq true
+    end
+  end
+end