property.rb in rantly-1.0.0

- old
+ new

@@ -4,10 +4,11 @@
 
 class Rantly::Property
   attr_reader :failed_data, :shrunk_failed_data, :io
 
   VERBOSITY = ENV.fetch('RANTLY_VERBOSE'){ 1 }.to_i
+  RANTLY_COUNT = ENV.fetch('RANTLY_COUNT'){ 100 }.to_i
 
   def io
     @io ||= if VERBOSITY >= 1
               STDOUT
             else
@@ -21,11 +22,11 @@
 
   def initialize(property)
     @property = property
   end
 
-  def check(n=100,limit=10,&assertion)
+  def check(n=RANTLY_COUNT,limit=10,&assertion)
     i = 0
     test_data = nil
     begin
       Rantly.singleton.generate(n,limit,@property) do |val|
         test_data = val
@@ -44,33 +45,42 @@
       io.puts
       io.puts "failure: #{i} tests, on:"
       pretty_print test_data
       @failed_data = test_data
       if @failed_data.respond_to?(:shrink)
-        @shrunk_failed_data = shrinkify(assertion, @failed_data)
-        io.puts "minimal failed data is:"
+        @shrunk_failed_data, @depth = shrinkify(assertion, @failed_data)
+        io.puts "minimal failed data (depth #{@depth}) is:"
         pretty_print @shrunk_failed_data
       end
       raise boom
     end
   end
 
-  # return the first success case
-  def shrinkify(assertion, data)
-    # We assume that data.shrink is non-destructive
-    return data if !data.shrinkable?
-    val = data.shrink
-    begin
-      assertion.call(val)
-      io.puts "found a reduced success:"
-      pretty_print val
-      return data
-    rescue Exception
-      io.puts "found a reduced failure case:"
-      pretty_print val
-      # recursively shrink failure case
-      return shrinkify(assertion,val)
+  # Explore the failures tree
+  def shrinkify(assertion, data, depth=0, iteration=0)
+    io.puts "Shrinking at depth #{depth}:"
+    pretty_print data
+
+    min_data = data
+    max_depth = depth
+    if data.shrinkable?
+      while iteration < 1024 do
+        # We assume that data.shrink is non-destructive
+        shrunk_data = data.shrink
+        begin
+          assertion.call(shrunk_data)
+        rescue Exception
+          # If the assertion was verified, recursively shrink failure case
+          branch_data, branch_depth, iteration = shrinkify(assertion, shrunk_data, depth + 1, iteration + 1)
+          if branch_depth > max_depth
+            min_data = branch_data
+            max_depth = branch_depth
+          end
+        end
+        break if !data.retry?
+      end
     end
+    return min_data, max_depth, iteration
   end
 
   def report
     distribs = self.classifiers.sort { |a,b| b[1] <=> a[1] }
     total = distribs.inject(0) { |sum,pair| sum + pair[1]}