Fix that `String#to_f` accepts consecutive `_` as a numeric expression

Consecutive `_` is not allowed as a numeric expression:

  1_2__3             #=> SyntaxError
  Float("1_2__3")    #=> ArgumentError
  Integer("1_2__3")  #=> ArgumentError
  "1_2__3".to_i      #=> 12

But `String#to_f` accept it, so I fixed the issue.

Before this patch:

  "1_2__3".to_f      #=> 123

After this patch:

  "1_2__3".to_f      #=> 12

1 files changed, 27 insertions, 9 deletions

diff --git a/mrbgems/mruby-kernel-ext/test/kernel.rb b/mrbgems/mruby-kernel-ext/test/kernel.rb
index ad9177165..2bd901a4c 100644
--- a/mrbgems/mruby-kernel-ext/test/kernel.rb
+++ b/mrbgems/mruby-kernel-ext/test/kernel.rb
@@ -49,24 +49,42 @@ assert('Kernel#__method__') do
 end
 
 assert('Kernel#Integer') do
-  assert_equal(26, Integer("0x1a"))
-  assert_equal(930, Integer("0930", 10))
-  assert_equal(7, Integer("111", 2))
-  assert_equal(0, Integer("0"))
-  assert_equal(0, Integer("00000"))
+  assert_operator(26, :eql?, Integer("0x1a"))
+  assert_operator(930, :eql?, Integer("0930", 10))
+  assert_operator(7, :eql?, Integer("111", 2))
+  assert_operator(0, :eql?, Integer("0"))
+  assert_operator(0, :eql?, Integer("00000"))
+  assert_operator(123, :eql?, Integer('1_2_3'))
   assert_raise(TypeError) { Integer(nil) }
+  assert_raise(ArgumentError) { Integer('a') }
+  assert_raise(ArgumentError) { Integer('4a5') }
+  assert_raise(ArgumentError) { Integer('1_2__3') }
+  assert_raise(ArgumentError) { Integer('68_') }
+  assert_raise(ArgumentError) { Integer("15\0") }
+  assert_raise(ArgumentError) { Integer("15.0") }
   skip unless Object.const_defined?(:Float)
-  assert_equal(123, Integer(123.999))
+  assert_operator(123, :eql?, Integer(123.999))
 end
 
 assert('Kernel#Float') do
   skip unless Object.const_defined?(:Float)
-  assert_equal(1.0, Float(1))
-  assert_equal(123.456, Float(123.456))
-  assert_equal(123.456, Float("123.456"))
+  assert_operator(1.0, :eql?, Float(1))
+  assert_operator(123.456, :eql?, Float(123.456))
+  assert_operator(123.456, :eql?, Float("123.456"))
+  assert_operator(123.0, :eql?, Float('1_2_3'))
+  assert_operator(12.34, :eql?, Float('1_2.3_4'))
+  assert_operator(0.9, :eql?, Float('.9'))
   assert_raise(TypeError) { Float(nil) }
   assert_raise(ArgumentError) { Float("1.5a") }
   assert_raise(ArgumentError) { Float("1.5\0") }
+  assert_raise(ArgumentError) { Float('a') }
+  assert_raise(ArgumentError) { Float('4a5') }
+  assert_raise(ArgumentError) { Float('1_2__3') }
+  assert_raise(ArgumentError) { Float('68_') }
+  assert_raise(ArgumentError) { Float('68._7') }
+  assert_raise(ArgumentError) { Float('68.7_') }
+  assert_raise(ArgumentError) { Float('_68') }
+  assert_raise(ArgumentError) { Float('1_2.3__4') }
 end
 
 assert('Kernel#String') do