[rspec-users] Stubbing Kernel.` (backquote)

[George Anderson]

I'm trying to stub(!) the Kernel.` (backquote) method and I'm having
confusing (to me) results. Here's the method I'm spec'ing:

class Barcode
  ...
  def raw_barcodes
    self.make_temporary_copy
    `OcrBarcode #{self.temp_file_path}`
  end
  ...
end

And this is my (newbish) attempt at the spec:

describe "Calling @barcode.raw_barcodes" do
  before(:each) do
    File.stub!(:exist?).and_return(true)
    @barcode = Barcode.new('path/to/valid.pdf')
    Kernel.stub!('`'.to_sym)
  end
  it "should make a copy of the file" do
    @barcode.should_receive(:make_temporary_copy)
    @barcode.raw_barcodes
  end
  it "should make a system call to OcrBarcode"
  it "should make the system call to OcrBarcode passing in the
temporary copy of the file"
  it "should create foo.pdf.barcode"
end

When I run this (using cmd-d in the TM bundle), the test passes, but I
get this line injected about the green "should make a copy of the
file":

/Users/george/work/simplify_md/vendor/plugins/rspec/lib/spec/mocks/proxy.rb:129:
command not found: OcrBarcode
/Users/george/work/simplify_md/tmp/valid_2007_10_24_111354_EDT.pdf

(all one line)


Significantly, if I remove the stub (Kernel.stub!('`'.to_sym)), I get
the same result: passing with the same "command not found" message.

Is there an accepted way to stub subshell calls?

Thanks,

/g

-- 

George Anderson

BenevolentCode LLC
O: (410) 461-7553
C: (410) 218-5185

george at benevolentcode.com