1 files changed, 34 insertions, 0 deletions
diff --git a/spec/ruby/command_line/dash_n_spec.rb b/spec/ruby/command_line/dash_n_spec.rb
new file mode 100644
index 0000000000..f4dd9f1851
--- /dev/null
+++ b/spec/ruby/command_line/dash_n_spec.rb
@@ -0,0 +1,34 @@
+describe "The -n command line option" do
+  before :each do
+    @names  = fixture __FILE__, "names.txt"
+  end
+
+  it "runs the code in loop conditional on Kernel.gets()" do
+    ruby_exe("puts $_", options: "-n", escape: true,
+                        args: " < #{@names}").should ==
+      "alice\nbob\njames\n"
+  end
+
+  it "only evaluates BEGIN blocks once" do
+    ruby_exe("BEGIN { puts \"hi\" }; puts $_", options: "-n", escape: true,
+                                               args: " < #{@names}").should ==
+      "hi\nalice\nbob\njames\n"
+  end
+
+  it "only evaluates END blocks once" do
+    ruby_exe("puts $_; END {puts \"bye\"}", options: "-n", escape: true,
+                                            args: " < #{@names}").should ==
+      "alice\nbob\njames\nbye\n"
+  end
+
+  it "allows summing over a whole file" do
+    script = <<-script
+    BEGIN { $total = 0 }
+    $total += 1
+    END { puts $total }
+    script
+    ruby_exe(script, options: "-n", escape: true,
+                     args: " < #{@names}").should ==
+      "3\n"
+  end
+end