Add tests with unknown directives for Array#pack, String#unpack

Author: trinistr

core/array/pack/unknown_spec.rb

@@ -0,0 +1,7 @@
+require_relative '../../../spec_helper'
+
+describe "Array#pack with unknown directive" do
+  it "raises ArgumentError" do
+    -> { [1, 2, 3].pack("ijk") }.should raise_error(ArgumentError, "unknown pack directive 'k' in 'ijk'")
+  end
+end

core/string/unpack_spec.rb

@@ -29,4 +29,8 @@
   it "raises an ArgumentError when the offset is larger than the string" do
     -> { "a".unpack("C", offset: 2) }.should raise_error(ArgumentError, "offset outside of string")
   end
+
+  it "raises an ArgumentError if a directive is unknown" do
+    -> { "a".unpack("ijk") }.should raise_error(ArgumentError, "unknown unpack directive 'k' in 'ijk'")
+  end
 end