1 files changed, 36 insertions, 0 deletions
diff --git a/spec/ruby/command_line/dash_encoding_spec.rb b/spec/ruby/command_line/dash_encoding_spec.rb
new file mode 100644
index 0000000000..5803d328c1
--- /dev/null
+++ b/spec/ruby/command_line/dash_encoding_spec.rb
@@ -0,0 +1,36 @@
+require_relative '../spec_helper'
+
+describe "The --encoding command line option" do
+  before :each do
+    @test_string = "print [Encoding.default_external.name, Encoding.default_internal&.name].inspect"
+    @enc2 = Encoding::ISO_8859_1
+  end
+
+  describe "sets Encoding.default_external and optionally Encoding.default_internal" do
+    it "if given a single encoding with an =" do
+      ruby_exe(@test_string, options: "--disable-gems --encoding=big5").should == [Encoding::Big5.name, nil].inspect
+    end
+
+    it "if given a single encoding as a separate argument" do
+      ruby_exe(@test_string, options: "--disable-gems --encoding big5").should == [Encoding::Big5.name, nil].inspect
+    end
+
+    it "if given two encodings with an =" do
+      ruby_exe(@test_string, options: "--disable-gems --encoding=big5:#{@enc2}").should == [Encoding::Big5.name, @enc2.name].inspect
+    end
+
+    it "if given two encodings as a separate argument" do
+      ruby_exe(@test_string, options: "--disable-gems --encoding big5:#{@enc2}").should == [Encoding::Big5.name, @enc2.name].inspect
+    end
+  end
+
+  it "does not accept a third encoding" do
+    options = {
+      options: "--disable-gems --encoding big5:#{@enc2}:utf-32le",
+      args: "2>&1",
+      exit_status: 1
+    }
+
+    ruby_exe(@test_string, options).should =~ /extra argument for --encoding: utf-32le/
+  end
+end