require 'test/unit' require 'prime' require 'stringio' class TestPrime < Test::Unit::TestCase # The first 100 prime numbers PRIMES = [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, ] def test_each primes = [] Prime.each do |p| break if p > 541 primes << p end assert_equal PRIMES, primes end def test_each_by_prime_number_theorem 3.upto(15) do |i| max = 2**i primes = [] Prime.each do |p| break if p >= max primes << p end # Prime number theorem assert primes.length >= max/Math.log(max) delta = 0.05 li = (2..max).step(delta).inject(0){|sum,x| sum + delta/Math.log(x)} assert primes.length <= li end end def test_each_without_block enum = Prime.each assert enum.respond_to?(:each) assert enum.kind_of?(Enumerable) assert enum.respond_to?(:with_index) assert enum.respond_to?(:next) assert enum.respond_to?(:succ) assert enum.respond_to?(:rewind) end def test_new buf = StringIO.new('', 'w') orig, $stderr = $stderr, buf enum = Prime.new assert !buf.string.empty? $stderr = orig assert enum.respond_to?(:each) assert enum.kind_of?(Enumerable) assert enum.respond_to?(:succ) assert Prime === enum ensure $stderr = orig end def test_enumerator_succ enum = Prime.each assert_equal PRIMES[0, 50], 50.times.map{ enum.succ } assert_equal PRIMES[50, 50], 50.times.map{ enum.succ } enum.rewind assert_equal PRIMES[0, 100], 100.times.map{ enum.succ } end def test_enumerator_with_index enum = Prime.each last = -1 enum.with_index do |p,i| break if i >= 100 assert_equal last+1, i assert_equal PRIMES[i], p last = i end end def test_default_instance_does_not_have_compatibility_methods assert !Prime.instance.respond_to?(:succ) assert !Prime.instance.respond_to?(:next) end class TestInteger < Test::Unit::TestCase def test_prime_division pd = PRIMES.inject(&:*).prime_division assert_equal PRIMES.map{|p| [p, 1]}, pd pd = (-PRIMES.inject(&:*)).prime_division assert_equal [-1, *PRIMES].map{|p| [p, 1]}, pd end def test_from_prime_division assert_equal PRIMES.inject(&:*), Integer.from_prime_division(PRIMES.map{|p| [p,1]}) assert_equal -PRIMES.inject(&:*), Integer.from_prime_division([[-1, 1]] + PRIMES.map{|p| [p,1]}) end def test_prime? # zero and unit assert !0.prime? assert !1.prime? # small primes assert 2.prime? assert 3.prime? # squared prime assert !4.prime? assert !9.prime? # mersenne numbers assert (2**31-1).prime? assert !(2**32-1).prime? # fermat numbers assert (2**(2**4)+1).prime? assert !(2**(2**5)+1).prime? # Euler! # large composite assert !((2**13-1) * (2**17-1)).prime? # factorial assert !(2...100).inject(&:*).prime? # negative assert !-1.prime? assert -2.prime? assert -3.prime? assert !-4.prime? end end end