Include the spec location in warnings if we can't generate a call site.

lib/rspec/core.rb

@@ -16,7 +16,6 @@
 
 require 'rspec/support/caller_filter'
 require 'rspec/core/warnings'
-require 'rspec/support/warnings'
 
 require_rspec['core/flat_map']
 require_rspec['core/filter_manager']
@@ -45,6 +44,8 @@
 module RSpec
   autoload :SharedContext, 'rspec/core/shared_context'
 
+  extend RSpec::Core::Warnings
+
   # @private
   def self.wants_to_quit
   # Used internally to determine what to do when a SIGINT is received

lib/rspec/core/warnings.rb

@@ -1,22 +1,38 @@
+require "rspec/support/warnings"
+
 module RSpec
+  module Core
+    module Warnings
+      # @private
+      #
+      # Used internally to print deprecation warnings
+      def deprecate(deprecated, data = {})
+        RSpec.configuration.reporter.deprecation(
+          {
+            :deprecated => deprecated,
+            :call_site => CallerFilter.first_non_rspec_line
+          }.merge(data)
+        )
+      end
 
-  # @private
-  #
-  # Used internally to print deprecation warnings
-  def self.deprecate(deprecated, data = {})
-    RSpec.configuration.reporter.deprecation(
-      {
-        :deprecated => deprecated,
-        :call_site => CallerFilter.first_non_rspec_line
-      }.merge(data)
-    )
-  end
+      # @private
+      #
+      # Used internally to print deprecation warnings
+      def warn_deprecation(message)
+        RSpec.configuration.reporter.deprecation :message => message
+      end
 
-  # @private
-  #
-  # Used internally to print deprecation warnings
-  def self.warn_deprecation(message)
-    RSpec.configuration.reporter.deprecation :message => message
-  end
+      def warn_with(message, options = {})
+        if options[:use_spec_location_as_call_site]
+          message += "." unless message.end_with?(".")
 
+          if RSpec.current_example
+            message += " Warning generated from spec at `#{RSpec.current_example.location}`."
+          end
+        end
+
+        super(message, options)
+      end
+    end
+  end
 end

spec/rspec/core/warnings_spec.rb

@@ -26,4 +26,42 @@
     end
   end
 
+  describe "#warn_with" do
+    context "when :use_spec_location_as_call_site => true is passed" do
+      let(:options) {
+        {
+          :use_spec_location_as_call_site => true,
+          :call_site                      => nil,
+        }
+      }
+
+      it "adds the source location of spec" do
+        line = __LINE__ - 1
+        file_path = RSpec::Core::Metadata.relative_path(__FILE__)
+        expect(Kernel).to receive(:warn).with(/The warning. Warning generated from spec at `#{file_path}:#{line}`./)
+
+        RSpec.warn_with("The warning.", options)
+      end
+
+      it "appends a period to the supplied message if one is not present" do
+        line = __LINE__ - 1
+        file_path = RSpec::Core::Metadata.relative_path(__FILE__)
+        expect(Kernel).to receive(:warn).with(/The warning. Warning generated from spec at `#{file_path}:#{line}`./)
+
+        RSpec.warn_with("The warning", options)
+      end
+
+      context "when there is no current example" do
+        before do
+          allow(RSpec).to receive(:current_example).and_return(nil)
+        end
+
+        it "adds no message about the spec location" do
+          expect(Kernel).to receive(:warn).with(/The warning\.$/)
+
+          RSpec.warn_with("The warning.", options)
+        end
+      end
+    end
+  end
 end