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#!/usr/bin/env ruby
require File.expand_path(File.join(File.dirname(__FILE__), "test_helper"))
module AllIntegers
def test_have_correct_num_bytes
all_classes do |int_class|
_(int_class.new.num_bytes).must_equal @nbytes
end
end
def test_have_a_sensible_value_of_zero
all_classes do |int_class|
_(int_class.new).must_equal 0
end
end
def test_avoid_underflow
all_classes do |int_class|
subject = int_class.new
subject.assign(min_value - 1)
_(subject).must_equal min_value
end
end
def test_avoid_overflow
all_classes do |int_class|
subject = int_class.new
subject.assign(max_value + 1)
_(subject).must_equal max_value
end
end
def test_assign_values
all_classes do |int_class|
subject = int_class.new
test_int = gen_test_int
subject.assign(test_int)
_(subject).must_equal test_int
end
end
def test_assign_values_from_other_int_objects
all_classes do |int_class|
src = int_class.new
src.assign(gen_test_int)
subject = int_class.new
subject.assign(src)
_(subject).must_equal src
end
end
def test_symmetrically_read_and_write_a_positive_number
all_classes do |int_class|
subject = int_class.new
subject.assign(gen_test_int)
_(subject.value_read_from_written).must_equal subject
end
end
def test_symmetrically_read_and_write_a_negative_number
all_classes do |int_class|
if @signed
subject = int_class.new
subject.assign(-gen_test_int)
_(subject.value_read_from_written).must_equal subject
end
end
end
def test_convert_a_positive_number_to_string
all_classes do |int_class|
val = gen_test_int
subject = int_class.new
subject.assign(val)
_(subject.to_binary_s).must_equal_binary int_to_binary_str(val)
end
end
def test_convert_a_negative_number_to_string
all_classes do |int_class|
if @signed
val = -gen_test_int
subject = int_class.new
subject.assign(val)
_(subject.to_binary_s).must_equal_binary int_to_binary_str(val)
end
end
end
def all_classes(&block)
@ints.each_pair do |int_class, nbytes|
@nbytes = nbytes
yield int_class
end
end
def min_value
if @signed
-max_value - 1
else
0
end
end
def max_value
if @signed
(1 << (@nbytes * 8 - 1)) - 1
else
(1 << (@nbytes * 8)) - 1
end
end
def gen_test_int
# resulting int is guaranteed to be +ve for signed or unsigned integers
(0 ... @nbytes).inject(0) { |val, i| (val << 8) | ((val + 0x11) % 0x100) }
end
def int_to_binary_str(val)
str = "".dup.force_encoding(Encoding::BINARY)
v = val & ((1 << (@nbytes * 8)) - 1)
@nbytes.times do
str.concat(v & 0xff)
v >>= 8
end
(@endian == :little) ? str : str.reverse
end
def create_mapping_of_class_to_nbits(endian, signed)
base = signed ? "Int" : "Uint"
endian_str = (endian == :little) ? "le" : "be"
result = {}
result[BinData.const_get("#{base}8")] = 1
(1 .. 20).each do |nbytes|
nbits = nbytes * 8
class_name = "#{base}#{nbits}#{endian_str}"
result[BinData.const_get(class_name)] = nbytes
end
result
end
end
describe "All signed big endian integers" do
include AllIntegers
before do
@endian = :big
@signed = true
@ints = create_mapping_of_class_to_nbits(@endian, @signed)
end
end
describe "All unsigned big endian integers" do
include AllIntegers
before do
@endian = :big
@signed = false
@ints = create_mapping_of_class_to_nbits(@endian, @signed)
end
end
describe "All signed little endian integers" do
include AllIntegers
before do
@endian = :little
@signed = true
@ints = create_mapping_of_class_to_nbits(@endian, @signed)
end
end
describe "All unsigned little endian integers" do
include AllIntegers
before do
@endian = :little
@signed = false
@ints = create_mapping_of_class_to_nbits(@endian, @signed)
end
end
describe "Custom defined integers" do
it "fail unless bits are a multiple of 8" do
_ { BinData::Uint7le }.must_raise NameError
_ { BinData::Uint7be }.must_raise NameError
_ { BinData::Int7le }.must_raise NameError
_ { BinData::Int7be }.must_raise NameError
end
end
|
