1 files changed, 139 insertions, 0 deletions
diff --git a/tools/fuzz.rb b/tools/fuzz.rb
new file mode 100755
index 0000000..4dacd95
--- /dev/null
+++ b/tools/fuzz.rb
@@ -0,0 +1,139 @@
+require 'json'
+
+require 'iconv'
+ISO_8859_1_TO_UTF8 = Iconv.new('utf-8', 'iso-8859-15')
+class ::String
+  def to_utf8
+    ISO_8859_1_TO_UTF8.iconv self
+  end
+end
+
+class Fuzzer
+  def initialize(n, freqs = {})
+    sum = freqs.inject(0.0) { |s, x| s + x.last }
+    freqs.each_key { |x| freqs[x] /= sum }
+    s = 0.0
+    freqs.each_key do |x|
+      freqs[x] = s .. (s + t = freqs[x])
+      s += t
+    end
+    @freqs = freqs
+    @n = n
+    @alpha = (0..0xff).to_a
+  end
+
+  def random_string
+    s = ''
+    30.times { s << @alpha[rand(@alpha.size)] }
+    s.to_utf8
+  end
+
+  def pick
+    r = rand
+    found = @freqs.find { |k, f| f.include? rand }
+    found && found.first
+  end
+
+  def make_pick
+    k = pick
+    case
+    when k == Hash, k == Array
+      k.new
+    when k == true, k == false, k == nil
+      k
+    when k == String
+      random_string
+    when k == Fixnum
+      rand(2 ** 30) - 2 ** 29
+    when k == Bignum
+      rand(2 ** 70) - 2 ** 69
+    end
+  end
+
+  def fuzz(current = nil)
+    if @n > 0
+      case current
+      when nil
+        @n -= 1
+        current = fuzz [ Hash, Array ][rand(2)].new
+      when Array
+        while @n > 0
+          @n -= 1
+          current << case p = make_pick
+          when Array, Hash
+            fuzz(p)
+          else
+            p
+          end
+        end
+      when Hash
+        while @n > 0
+          @n -= 1
+          current[random_string] = case p = make_pick
+          when Array, Hash
+            fuzz(p)
+          else
+            p
+          end
+        end
+      end
+    end
+    current
+  end
+end
+
+class MyState < JSON.state
+  WS = " \r\t\n"
+
+  def initialize
+    super(
+          :indent       => make_spaces,
+          :space        => make_spaces,
+          :space_before => make_spaces,
+          :object_nl    => make_spaces,
+          :array_nl     => make_spaces,
+          :max_nesting  => false
+         )
+  end
+
+  def make_spaces
+    s = ''
+    rand(1).times { s << WS[rand(WS.size)] }
+    s
+  end
+end
+
+n = (ARGV.shift || 500).to_i
+loop do
+  fuzzer = Fuzzer.new(n,
+                      Hash => 25,
+                      Array => 25,
+                      String => 10,
+                      Fixnum => 10,
+                      Bignum => 10,
+                      nil => 5,
+                      true => 5,
+                      false => 5
+                     )
+  o1 = fuzzer.fuzz
+  json = JSON.generate o1, MyState.new
+  if $DEBUG
+    puts "-" * 80
+    puts json, json.size
+  else 
+    puts json.size
+  end
+  begin
+    o2 = JSON.parse(json, :max_nesting => false)
+  rescue JSON::ParserError => e
+    puts "Caught #{e.class}: #{e.message}\n#{e.backtrace * "\n"}"
+    puts "o1 = #{o1.inspect}", "json = #{json}", "json_str = #{json.inspect}"
+    puts "locals = #{local_variables.inspect}"
+    exit
+  end
+  if o1 != o2
+    puts "mismatch", "o1 = #{o1.inspect}", "o2 = #{o2.inspect}",
+      "json = #{json}", "json_str = #{json.inspect}"
+    puts "locals = #{local_variables.inspect}"
+  end
+end