property.rb in prop_check-0.14.0

- old
+ new

@@ -5,13 +5,19 @@
 require 'prop_check/property/output_formatter'
 require 'prop_check/property/shrinker'
 require 'prop_check/hooks'
 module PropCheck
   ##
-  # Run properties
+  # Create and run property-checks.
+  #
+  # For simple usage, see `.forall`.
+  #
+  # For advanced usage, call `PropCheck::Property.new(...)` and then configure it to your liking
+  # using e.g. `#with_config`, `#before`, `#after`, `#around` etc.
+  # Each of these methods will return a new `Property`, so earlier properties are not mutated.
+  # This allows you to re-use configuration and hooks between multiple tests.
   class Property
-
     ##
     # Main entry-point to create (and possibly immediately run) a property-test.
     #
     # This method accepts a list of generators and a block.
     # The block will then be executed many times, passing the values generated by the generators
@@ -34,11 +40,10 @@
     # If you do not pass a block right away,
     # a Property object is returned, which you can call the other instance methods
     # of this class on before finally passing a block to it using `#check`.
     # (so `forall(Generators.integer) do |val| ... end` and forall(Generators.integer).check do |val| ... end` are the same)
     def self.forall(*bindings, **kwbindings, &block)
-
       property = new(*bindings, **kwbindings)
 
       return property.check(&block) if block_given?
 
       property
@@ -59,23 +64,29 @@
     # See PropCheck::Property::Configuration for more info on available settings.
     def self.configure
       yield(configuration)
     end
 
-    attr_reader :bindings, :condition
-
     def initialize(*bindings, **kwbindings)
-      raise ArgumentError, 'No bindings specified!' if bindings.empty? && kwbindings.empty?
-
-      # @bindings = bindings
-      # @kwbindings = kwbindings
-      @gen = gen_from_bindings(bindings, kwbindings)
-      @condition = proc { true }
       @config = self.class.configuration
       @hooks = PropCheck::Hooks.new
+
+      @gen = gen_from_bindings(bindings, kwbindings) unless bindings.empty? && kwbindings.empty?
+      freeze
     end
 
+    # [:condition, :config, :hooks, :gen].each do |symbol|
+    #   define_method(symbol) do
+    #     self.instance_variable_get("@#{symbol}")
+    #   end
+
+    #   protected define_method("#{symbol}=") do |value|
+    #     duplicate = self.dup
+    #     duplicate.instance_variable_set("@#{symbol}", value)
+    #     duplicate
+    #   end
+
     ##
     # Returns the configuration of this property
     # for introspection.
     #
     # See PropCheck::Property::Configuration for more info on available settings.
@@ -89,55 +100,68 @@
     #
     # If no other changes need to occur before you want to check the property,
     # you can immediately pass a block to this method.
     # (so `forall(a: Generators.integer).with_config(verbose: true) do ... end` is the same as `forall(a: Generators.integer).with_config(verbose: true).check do ... end`)
     def with_config(**config, &block)
-      @config = @config.merge(config)
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@config, @config.merge(config))
+      duplicate.freeze
 
-      return self.check(&block) if block_given?
+      return duplicate.check(&block) if block_given?
 
-      self
+      duplicate
     end
 
+    def with_bindings(*bindings, **kwbindings)
+      raise ArgumentError, 'No bindings specified!' if bindings.empty? && kwbindings.empty?
+
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@gen, gen_from_bindings(bindings, kwbindings))
+      duplicate.freeze
+      duplicate
+    end
+
     ##
     # filters the generator using the  given `condition`.
     # The final property checking block will only be run if the condition is truthy.
     #
     # If wanted, multiple `where`-conditions can be specified on a property.
     # Be aware that if you filter away too much generated inputs,
     # you might encounter a GeneratorExhaustedError.
     # Only filter if you have few inputs to reject. Otherwise, improve your generators.
     def where(&condition)
-      # original_condition = @condition.dup
-      # @condition = proc do |val|
-      #   call_splatted(val, &original_condition) && call_splatted(val, &condition)
-      #   # original_condition.call(val) && condition.call(val)
-      # end
-      @gen = @gen.where(&condition)
+      raise ArgumentError, 'No generator bindings specified! #where should be called after `#forall` or `#with_bindings`.' unless @gen
 
-      self
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@gen, @gen.where(&condition))
+      duplicate.freeze
+      duplicate
     end
 
 
     ##
     # Calls `hook` before each time a check is run with new data.
     #
     # This is useful to add setup logic
     # When called multiple times, earlier-added hooks will be called _before_ `hook` is called.
     def before(&hook)
-      @hooks.add_before(&hook)
-      self
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@hooks, @hooks.add_before(&hook))
+      duplicate.freeze
+      duplicate
     end
 
     ##
     # Calls `hook` after each time a check is run with new data.
     #
     # This is useful to add teardown logic
     # When called multiple times, earlier-added hooks will be called _after_ `hook` is called.
     def after(&hook)
-      @hooks.add_after(&hook)
-      self
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@hooks, @hooks.add_after(&hook))
+      duplicate.freeze
+      duplicate
     end
 
     ##
     # Calls `hook` around each time a check is run with new data.
     #
@@ -150,12 +174,14 @@
     #
     # Note that if the block passed to `hook` raises an exception,
     # it is possible for the code after `yield` not to be called.
     # So make sure that cleanup logic is wrapped with the `ensure` keyword.
     def around(&hook)
-      @hooks.add_around(&hook)
-      self
+      duplicate = self.dup
+      duplicate.instance_variable_set(:@hooks, @hooks.add_around(&hook))
+      duplicate.freeze
+      duplicate
     end
 
     ##
     # Checks the property (after settings have been altered using the other instance methods in this class.)
     def check(&block)
@@ -236,9 +262,11 @@
 
       raise e, output_string, e.backtrace
     end
 
     private def attempts_enum(binding_generator)
+      ap @hooks
+
         @hooks
         .wrap_enum(raw_attempts_enum(binding_generator))
         .lazy
         .take(@config.n_runs)
     end