1 files changed, 33 insertions, 0 deletions
diff --git a/spec/ruby/command_line/dash_upper_k_spec.rb b/spec/ruby/command_line/dash_upper_k_spec.rb
new file mode 100644
index 0000000000..3c3b9fa4d3
--- /dev/null
+++ b/spec/ruby/command_line/dash_upper_k_spec.rb
@@ -0,0 +1,33 @@
+describe 'The -K command line option sets __ENCODING__' do
+  it "to Encoding::ASCII_8BIT with -Ka" do
+    ruby_exe("print __ENCODING__", options: '-Ka').should == Encoding::ASCII_8BIT.to_s
+  end
+
+  it "to Encoding::ASCII_8BIT with -KA" do
+    ruby_exe("print __ENCODING__", options: '-KA').should == Encoding::ASCII_8BIT.to_s
+  end
+
+  it "to Encoding::EUC_JP with -Ke" do
+    ruby_exe("print __ENCODING__", options: '-Ke').should == Encoding::EUC_JP.to_s
+  end
+
+  it "to Encoding::EUC_JP with -KE" do
+    ruby_exe("print __ENCODING__", options: '-KE').should == Encoding::EUC_JP.to_s
+  end
+
+  it "to Encoding::UTF_8 with -Ku" do
+    ruby_exe("print __ENCODING__", options: '-Ku').should == Encoding::UTF_8.to_s
+  end
+
+  it "to Encoding::UTF_8 with -KU" do
+    ruby_exe("print __ENCODING__", options: '-KU').should == Encoding::UTF_8.to_s
+  end
+
+  it "to Encoding::Windows_31J with -Ks" do
+    ruby_exe("print __ENCODING__", options: '-Ks').should == Encoding::Windows_31J.to_s
+  end
+
+  it "to Encoding::Windows_31J with -KS" do
+    ruby_exe("print __ENCODING__", options: '-KS').should == Encoding::Windows_31J.to_s
+  end
+end