Updates for frozen-string-literal compatibility.

lib/rspec/mocks/error_generator.rb

@@ -57,10 +57,10 @@ def raise_unexpected_message_args_error(expectation, args_for_multiple_calls, so
 
       # @private
       def raise_missing_default_stub_error(expectation, args_for_multiple_calls)
-        message = error_message(expectation, args_for_multiple_calls)
-        message << "\n Please stub a default value first if message might be received with other args as well. \n"
-
-        __raise message
+        __raise(
+          error_message(expectation, args_for_multiple_calls) +
+          "\n Please stub a default value first if message might be received with other args as well. \n"
+        )
       end
 
       # @private
@@ -69,7 +69,7 @@ def raise_similar_message_args_error(expectation, args_for_multiple_calls, backt
       end
 
       def default_error_message(expectation, expected_args, actual_args)
-        "#{intro} received #{expectation.message.inspect} #{unexpected_arguments_message(expected_args, actual_args)}"
+        "#{intro} received #{expectation.message.inspect} #{unexpected_arguments_message(expected_args, actual_args)}".dup
       end
 
       # rubocop:disable Style/ParameterLists
@@ -87,14 +87,14 @@ def raise_expectation_error(message, expected_received_count, argument_list_matc
       def raise_unimplemented_error(doubled_module, method_name, object)
         message = case object
                   when InstanceVerifyingDouble
-                    "the %s class does not implement the instance method: %s" <<
+                    "the %s class does not implement the instance method: %s".dup <<
                       if ObjectMethodReference.for(doubled_module, method_name).implemented?
                         ". Perhaps you meant to use `class_double` instead?"
                       else
                         ""
                       end
                   when ClassVerifyingDouble
-                    "the %s class does not implement the class method: %s" <<
+                    "the %s class does not implement the class method: %s".dup <<
                       if InstanceMethodReference.for(doubled_module, method_name).implemented?
                         ". Perhaps you meant to use `instance_double` instead?"
                       else

spec/rspec/mocks/any_instance_spec.rb

@@ -378,12 +378,12 @@ def private_method; :private_method_return_value; end
 
           it "works with the non-standard constructor \"\"" do
             allow_any_instance_of(String).to receive(:foo).and_return(1)
-            expect("".foo).to eq(1)
+            expect("".dup.foo).to eq(1)
           end
 
           it "works with the non-standard constructor \'\'" do
             allow_any_instance_of(String).to receive(:foo).and_return(1)
-            expect(''.foo).to eq(1)
+            expect(''.dup.foo).to eq(1)
           end
 
           it "works with the non-standard constructor module" do
@@ -545,10 +545,10 @@ def inspect
 
         it "does not set the expectation on every instance" do
           # Setup an unrelated object of the same class that won't receive the expected message.
-          allow('non-related object').to receive(:non_related_method)
+          allow('non-related object'.dup).to receive(:non_related_method)
 
           expect_any_instance_of(Object).to receive(:foo)
-          'something'.foo
+          'something'.dup.foo
         end
 
         it "does not modify the return value of stubs set on an instance" do

spec/rspec/mocks/diffing_spec.rb

@@ -157,7 +157,7 @@ def inspect
           expect(RSpec::Support.is_a_matcher?(collab)).to be true
 
           collab_inspect = collab.inspect
-          collab_pp = PP.pp(collab, "").strip
+          collab_pp = PP.pp(collab, "".dup).strip
 
           expect(d).to receive(:foo).with(collab)
           expect {

spec/rspec/mocks/message_expectation_string_representation_spec.rb

@@ -10,7 +10,7 @@ module Mocks
       end
 
       example "for a raw message expectation on a partial double" do
-        expect(allow("partial double").to receive(:foo)).to have_string_representation(
+        expect(allow("partial double".dup).to receive(:foo)).to have_string_representation(
           '#<RSpec::Mocks::MessageExpectation "partial double".foo(any arguments)>'
         )
       end

spec/rspec/mocks_spec.rb

@@ -45,7 +45,7 @@
 
   describe ".teardown" do
     it "resets method stubs" do
-      string = "foo"
+      string = "foo".dup
       allow(string).to receive(:bar)
       RSpec::Mocks.teardown
       expect { string.bar }.to raise_error(NoMethodError)
@@ -56,7 +56,7 @@
       RSpec::Mocks.teardown
       RSpec::Mocks.teardown
 
-      string = "foo"
+      string = "foo".dup
       expect { allow(string).to receive(:bar) }.to raise_error(RSpec::Mocks::OutsideOfExampleError)
 
       RSpec::Mocks.setup
@@ -157,10 +157,10 @@
       before(:all) do
         RSpec::Mocks.with_temporary_scope do
           allow_any_instance_of(String).to receive(:sum_with) { |val, x| val + x }
-          @sum = "foo".sum_with("bar")
+          @sum = "foo".dup.sum_with("bar")
         end
 
-        capture_error { "you".sum_with("me") }
+        capture_error { "you".dup.sum_with("me") }
       end
 
       it 'allows the stub to be used' do