1 files changed, 21 insertions, 24 deletions
diff --git a/spec/ruby/core/string/shared/concat.rb b/spec/ruby/core/string/shared/concat.rb
index d6ffad7d4d..dded9a69e7 100644
--- a/spec/ruby/core/string/shared/concat.rb
+++ b/spec/ruby/core/string/shared/concat.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 describe :string_concat, shared: true do
   it "concatenates the given argument to self and returns self" do
     str = 'hello '
@@ -5,18 +6,6 @@ describe :string_concat, shared: true do
     str.should == "hello world"
   end
 
-  it "converts the given argument to a String using to_str" do
-    obj = mock('world!')
-    obj.should_receive(:to_str).and_return("world!")
-    a = 'hello '.send(@method, obj)
-    a.should == 'hello world!'
-  end
-
-  it "raises a TypeError if the given argument can't be converted to a String" do
-    -> { 'hello '.send(@method, [])        }.should raise_error(TypeError)
-    -> { 'hello '.send(@method, mock('x')) }.should raise_error(TypeError)
-  end
-
   it "raises a FrozenError when self is frozen" do
     a = "hello"
     a.freeze
@@ -39,18 +28,6 @@ describe :string_concat, shared: true do
     str.should be_an_instance_of(StringSpecs::MyString)
   end
 
-  ruby_version_is ''...'2.7' do
-    it "taints self if other is tainted" do
-      "x".send(@method, "".taint).should.tainted?
-      "x".send(@method, "y".taint).should.tainted?
-    end
-
-    it "untrusts self if other is untrusted" do
-      "x".send(@method, "".untrust).should.untrusted?
-      "x".send(@method, "y".untrust).should.untrusted?
-    end
-  end
-
   describe "with Integer" do
     it "concatenates the argument interpreted as a codepoint" do
       b = "".send(@method, 33)
@@ -160,3 +137,23 @@ describe :string_concat_encoding, shared: true do
     end
   end
 end
+
+describe :string_concat_type_coercion, shared: true do
+  it "converts the given argument to a String using to_str" do
+    obj = mock('world!')
+    obj.should_receive(:to_str).and_return("world!")
+    a = 'hello '.send(@method, obj)
+    a.should == 'hello world!'
+  end
+
+  it "raises a TypeError if the given argument can't be converted to a String" do
+    -> { 'hello '.send(@method, [])        }.should raise_error(TypeError)
+    -> { 'hello '.send(@method, mock('x')) }.should raise_error(TypeError)
+  end
+
+  it "raises a NoMethodError if the given argument raises a NoMethodError during type coercion to a String" do
+    obj = mock('world!')
+    obj.should_receive(:to_str).and_raise(NoMethodError)
+    -> { 'hello '.send(@method, obj) }.should raise_error(NoMethodError)
+  end
+end