1 files changed, 26 insertions, 0 deletions
diff --git a/spec/ruby/core/argf/fileno_spec.rb b/spec/ruby/core/argf/fileno_spec.rb
new file mode 100644
index 0000000000..99245f043c
--- /dev/null
+++ b/spec/ruby/core/argf/fileno_spec.rb
@@ -0,0 +1,26 @@
+require_relative '../../spec_helper'
+
+describe "ARGF.fileno" do
+  before :each do
+    @file1 = fixture __FILE__, "file1.txt"
+    @file2 = fixture __FILE__, "file2.txt"
+  end
+
+  # NOTE: this test assumes that fixtures files have two lines each
+  it "returns the current file number on each file" do
+    argf [@file1, @file2] do
+      result = []
+      # returns first current file even when not yet open
+      result << @argf.fileno while @argf.gets
+      # returns last current file even when closed
+      result.map { |d| d.class }.should == [Integer, Integer, Integer, Integer]
+    end
+  end
+
+  it "raises an ArgumentError when called on a closed stream" do
+    argf [@file1] do
+      @argf.read
+      -> { @argf.fileno }.should.raise(ArgumentError)
+    end
+  end
+end