describe :string_unpack_basic, shared: true do
  it "ignores whitespace in the format string" do
    "abc".unpack("a \t\n\v\f\r"+unpack_format).should.instance_of?(Array)
  end

  it "calls #to_str to coerce the directives string" do
    d = mock("unpack directive")
    d.should_receive(:to_str).and_return("a"+unpack_format)
    "abc".unpack(d).should.instance_of?(Array)
  end

  it "raises ArgumentError when a directive is unknown" do
    -> { "abcdefgh".unpack("a K" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive 'K' in 'a K#{unpack_format}'")
    -> { "abcdefgh".unpack("a 0" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive '0' in 'a 0#{unpack_format}'")
    -> { "abcdefgh".unpack("a :" + unpack_format) }.should.raise(ArgumentError, "unknown unpack directive ':' in 'a :#{unpack_format}'")
  end
end

describe :string_unpack_no_platform, shared: true do
  it "raises an ArgumentError when the format modifier is '_'" do
    -> { "abcdefgh".unpack(unpack_format("_")) }.should.raise(ArgumentError)
  end

  it "raises an ArgumentError when the format modifier is '!'" do
    -> { "abcdefgh".unpack(unpack_format("!")) }.should.raise(ArgumentError)
  end
end
