Try to reproduce RSpec example binding in Ractor (but cannot as of now)

lib/pbt.rb

@@ -13,10 +13,62 @@ class PropertyFailure < StandardError; end
   extend Check::RunnerMethods
   extend Check::ConfigurationMethods
 
+  require "prism"
+  class BlockInspector < Prism::Visitor
+    attr_reader :proc_str
+    def initialize(line)
+      @line = line
+      @proc_str = nil
+      super()
+    end
+
+    def visit_call_node(node)
+      if node.name == :property && node.block.opening_loc.start_line == @line
+        # Extract the block content
+        # e.g.
+        # "do |n|\n          raise unless n.is_a?(Integer)\n        end"
+        @proc_str = "(Proc.new " + node.block.slice + ")"
+      end
+
+      super
+    end
+  end
+
   # @param args [Array<Pbt::Arbitrary>]
   # @param kwargs [Hash<Symbol->Pbt::Arbitrary>]
   # @return [Property]
-  def self.property(*args, **kwargs, &predicate)
+  def self.property(ex, *args, **kwargs, &predicate)
+    # This code reproduces predicate block's content as String
+    file, line = predicate.source_location
+    res = Prism.parse_file(file)
+    foo = BlockInspector.new(line)
+    res.value.statements.accept(foo)
+    ps = foo.proc_str
+
+    # This works
+    # Get the object_id of the example instance and get the instance by the id
+    id = ex.object_id
+    pr1 = ObjectSpace._id2ref(id).instance_eval ps
+    pr1.call(1)
+
+    # This doesn't work. We need to create an example instance in Ractor block.
+    r = Ractor.new(id, ps) do |id, ps|
+      # If we can run the proc as if it's in a RSpec example instance
+      # we can use `expect`, `be`, `raise_error`, etc.
+      pr2 = ObjectSpace._id2ref(id).instance_eval ps
+      pr2.call(1)
+    end
+
+    begin
+      r.take
+    rescue => e
+      # --- Caused by: ---
+      # RangeError:
+      #   "3400" is id of the unshareable object on multi-ractor
+      #   ./lib/pbt.rb:49:in `_id2ref'
+      raise e.cause
+    end
+
     arb = to_arbitrary(args, kwargs)
     Check::Property.new(arb, &predicate)
   end

spec/e2e/prism_spec.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+RSpec.describe Pbt do
+  describe "arguments" do
+    it "passes a value that the given single arbitrary generates" do
+      RSpec::Matchers::BuiltIn.constants.each { |c| RSpec::Matchers::BuiltIn.const_get(c) }
+
+      r = Ractor.new do
+        loop do
+          v, msg = Ractor.receive
+          v.instance_eval msg
+        end
+      end
+
+      r.send([self, "expect(1).to eq 1"]) # move: true doesn't work by TypeError: can't create instance of singleton class
+
+      begin
+        r.take
+      rescue => e
+        raise e.cause
+      end
+
+      # Pbt.assert do
+      #   Pbt.property(self, Pbt.integer) do |n|
+      #     puts "called!!!!!!!!!!!!!"
+      #     puts n
+      #     raise unless n.is_a?(Integer)
+      #   end
+      # end
+    end
+  end
+end