1 files changed, 39 insertions, 0 deletions
diff --git a/spec/rubyspec/core/argf/rewind_spec.rb b/spec/rubyspec/core/argf/rewind_spec.rb
new file mode 100644
index 0000000000..d6abc3a856
--- /dev/null
+++ b/spec/rubyspec/core/argf/rewind_spec.rb
@@ -0,0 +1,39 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "ARGF.rewind" do
+  before :each do
+    @file1_name = fixture __FILE__, "file1.txt"
+    @file2_name = fixture __FILE__, "file2.txt"
+
+    @file1 = File.readlines @file1_name
+    @file2 = File.readlines @file2_name
+  end
+
+  # NOTE: this test assumes that fixtures files have two lines each
+  it "goes back to beginning of current file" do
+    argf [@file1_name, @file2_name] do
+      @argf.gets
+      @argf.rewind
+      @argf.gets.should == @file1.first
+
+      @argf.gets # finish reading file1
+
+      @argf.gets
+      @argf.rewind
+      @argf.gets.should == @file2.first
+    end
+  end
+
+  it "resets ARGF.lineno to 0" do
+    script = fixture __FILE__, "rewind.rb"
+    out = ruby_exe(script, args: [@file1_name, @file2_name])
+    out.should == "0\n1\n0\n"
+  end
+
+  it "raises an ArgumentError when end of stream reached" do
+    argf [@file1_name, @file2_name] do
+      @argf.read
+      lambda { @argf.rewind }.should raise_error(ArgumentError)
+    end
+  end
+end