Merge pull request #1078 from herwinw/kernel_sprintf_to_str

Add tests for to_str conversion in Kernel.(s)printf

core/kernel/printf_spec.rb

@@ -31,6 +31,13 @@
     object.should_receive(:write).with("string")
     Kernel.printf(object, "%s", "string")
   end
+
+  it "calls #to_str to convert the format object to a String" do
+    object = mock('format string')
+    object.should_receive(:to_str).and_return("to_str: %i")
+    $stdout.should_receive(:write).with("to_str: 42")
+    Kernel.printf($stdout, object, 42)
+  end
 end
 
 describe "Kernel.printf" do

core/kernel/sprintf_spec.rb

@@ -3,6 +3,14 @@
 require_relative 'shared/sprintf'
 require_relative 'shared/sprintf_encoding'
 
+describe :kernel_sprintf_to_str, shared: true do
+  it "calls #to_str to convert the format object to a String" do
+    obj = mock('format string')
+    obj.should_receive(:to_str).and_return("to_str: %i")
+    @method.call(obj, 42).should == "to_str: 42"
+  end
+end
+
 describe "Kernel#sprintf" do
   it_behaves_like :kernel_sprintf, -> format, *args {
     sprintf(format, *args)
@@ -11,6 +19,10 @@
   it_behaves_like :kernel_sprintf_encoding, -> format, *args {
     sprintf(format, *args)
   }
+
+  it_behaves_like :kernel_sprintf_to_str, -> format, *args {
+    sprintf(format, *args)
+  }
 end
 
 describe "Kernel.sprintf" do
@@ -21,4 +33,8 @@
   it_behaves_like :kernel_sprintf_encoding, -> format, *args {
     Kernel.sprintf(format, *args)
   }
+
+  it_behaves_like :kernel_sprintf_to_str, -> format, *args {
+    Kernel.sprintf(format, *args)
+  }
 end