require 'spec_helper'
require 'puppet/pops'
require 'puppet/loaders'
require 'puppet_spec/pops'
require 'puppet_spec/scope'

module FunctionAPISpecModule
  class TestDuck
  end

  class TestFunctionLoader < Puppet::Pops::Loader::StaticLoader
    def initialize
      @constants = {}
    end

    def add_function(name, function)
      set_entry(Puppet::Pops::Loader::TypedName.new(:function, name), function, __FILE__)
    end

    def add_type(name, type)
      set_entry(Puppet::Pops::Loader::TypedName.new(:type, name), type, __FILE__)
    end

    def set_entry(typed_name, value, origin = nil)
      @constants[typed_name] = Puppet::Pops::Loader::Loader::NamedEntry.new(typed_name, value, origin)
    end

    # override StaticLoader
    def load_constant(typed_name)
      @constants[typed_name]
    end
  end
end

describe 'the 4x function api' do
  include FunctionAPISpecModule
  include PuppetSpec::Pops
  include PuppetSpec::Scope

  let(:loader) { FunctionAPISpecModule::TestFunctionLoader.new }

  it 'allows a simple function to be created without dispatch declaration' do
    f = Puppet::Functions.create_function('min') do
      def min(x,y)
        x <= y ? x : y
      end
    end

    # the produced result is a Class inheriting from Function
    expect(f.class).to be(Class)
    expect(f.superclass).to be(Puppet::Functions::Function)
    # and this class had the given name (not a real Ruby class name)
    expect(f.name).to eql('min')
  end

  it 'refuses to create functions that are not based on the Function class' do
    expect do
      Puppet::Functions.create_function('testing', Object) {}
    end.to raise_error(ArgumentError, /function 'testing'.*Functions must be based on Puppet::Pops::Functions::Function. Got Object/)
  end

  it 'refuses to create functions with parameters that are not named with a symbol' do
    expect do
      Puppet::Functions.create_function('testing') do
        dispatch :test do
          param 'Integer', 'not_symbol'
        end
        def test(x)
        end
      end
    end.to raise_error(ArgumentError, /Parameter name argument must be a Symbol/)
  end

  it 'a function without arguments can be defined and called without dispatch declaration' do
    f = create_noargs_function_class()
    func = f.new(:closure_scope, :loader)
    expect(func.call({})).to eql(10)
  end

  it 'an error is raised when calling a no arguments function with arguments' do
    f = create_noargs_function_class()
    func = f.new(:closure_scope, :loader)
    expect{func.call({}, 'surprise')}.to raise_error(ArgumentError, "'test' expects no arguments, got 1")
  end

  it 'a simple function can be called' do
    f = create_min_function_class()
    # TODO: Bogus parameters, not yet used
    func = f.new(:closure_scope, :loader)
    expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
    expect(func.call({}, 10,20)).to eql(10)
  end

  it 'an error is raised if called with too few arguments' do
    f = create_min_function_class()
    # TODO: Bogus parameters, not yet used
    func = f.new(:closure_scope, :loader)
    expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
    expect do
      func.call({}, 10)
    end.to raise_error(ArgumentError, "'min' expects 2 arguments, got 1")
  end

  it 'an error is raised if called with too many arguments' do
    f = create_min_function_class()
    # TODO: Bogus parameters, not yet used
    func = f.new(:closure_scope, :loader)
    expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
    expect do
      func.call({}, 10, 10, 10)
    end.to raise_error(ArgumentError, "'min' expects 2 arguments, got 3")
  end

  it 'correct dispatch is chosen when zero parameter dispatch exists' do
    f = create_function_with_no_parameter_dispatch
    func = f.new(:closure_scope, :loader)
    expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
    expect(func.call({}, 1)).to eql(1)
  end

  it 'an error is raised if simple function-name and method are not matched' do
    expect do
      create_badly_named_method_function_class()
    end.to raise_error(ArgumentError, /Function Creation Error, cannot create a default dispatcher for function 'mix', no method with this name found/)
  end

  it 'the implementation separates dispatchers for different functions' do
    # this tests that meta programming / construction puts class attributes in the correct class
    f1 = create_min_function_class()
    f2 = create_max_function_class()

    d1 = f1.dispatcher
    d2 = f2.dispatcher

    expect(d1).to_not eql(d2)
    expect(d1.dispatchers[0]).to_not eql(d2.dispatchers[0])
  end

  context 'when using regular dispatch' do
    it 'a function can be created using dispatch and called' do
      f = create_min_function_class_using_dispatch()
      func = f.new(:closure_scope, :loader)
      expect(func.call({}, 3,4)).to eql(3)
    end

    it 'an error is raised with reference to given parameter names when called with mis-matched arguments' do
      f = create_min_function_class_using_dispatch()
      # TODO: Bogus parameters, not yet used
      func = f.new(:closure_scope, :loader)
      expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
      expect do
        func.call({}, 10, 'ten')
      end.to raise_error(ArgumentError, "'min' parameter 'b' expects a Numeric value, got String")
    end

    it 'an error includes optional indicators for last element' do
      f = create_function_with_optionals_and_repeated_via_multiple_dispatch()
      # TODO: Bogus parameters, not yet used
      func = f.new(:closure_scope, :loader)
      expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
      expect do
        func.call({}, 3, 10, 3, "4")
      end.to raise_error(ArgumentError, "'min' expects one of:
  (Numeric x, Numeric y, Numeric a?, Numeric b?, Numeric c*)
    rejected: parameter 'b' expects a Numeric value, got String
  (String x, String y, String a+)
    rejected: parameter 'x' expects a String value, got Integer")
    end

    it 'can create optional repeated parameter' do
      f = create_function_with_repeated
      func = f.new(:closure_scope, :loader)
      expect(func.call({})).to eql(0)
      expect(func.call({}, 1)).to eql(1)
      expect(func.call({}, 1, 2)).to eql(2)

      f = create_function_with_optional_repeated
      func = f.new(:closure_scope, :loader)
      expect(func.call({})).to eql(0)
      expect(func.call({}, 1)).to eql(1)
      expect(func.call({}, 1, 2)).to eql(2)
    end

    it 'can create required repeated parameter' do
      f = create_function_with_required_repeated
      func = f.new(:closure_scope, :loader)
      expect(func.call({}, 1)).to eql(1)
      expect(func.call({}, 1, 2)).to eql(2)
      expect { func.call({}) }.to raise_error(ArgumentError, "'count_args' expects at least 1 argument, got none")
    end

    it 'can create scope_param followed by repeated  parameter' do
      f = create_function_with_scope_param_required_repeat
      func = f.new(:closure_scope, :loader)
      expect(func.call({}, 'yay', 1,2,3)).to eql([{}, 'yay',1,2,3])
    end

    it 'a function can use inexact argument mapping' do
      f = create_function_with_inexact_dispatch
      func = f.new(:closure_scope, :loader)
      expect(func.call({}, 3.0,4.0,5.0)).to eql([Float, Float, Float])
      expect(func.call({}, 'Apple', 'Banana')).to eql([String, String])
    end

    it 'a function can be created using dispatch and called' do
      f = create_min_function_class_disptaching_to_two_methods()
      func = f.new(:closure_scope, :loader)
      expect(func.call({}, 3,4)).to eql(3)
      expect(func.call({}, 'Apple', 'Banana')).to eql('Apple')
    end

    it 'a function can not be created with parameters declared after a repeated parameter' do
      expect { create_function_with_param_after_repeated }.to raise_error(ArgumentError, 
        /function 't1'.*Parameters cannot be added after a repeated parameter/)
    end

    it 'a function can not be created with required parameters declared after optional ones' do
      expect { create_function_with_rq_after_opt }.to raise_error(ArgumentError, 
        /function 't1'.*A required parameter cannot be added after an optional parameter/)
    end

    it 'a function can not be created with required repeated parameters declared after optional ones' do
      expect { create_function_with_rq_repeated_after_opt }.to raise_error(ArgumentError,
        /function 't1'.*A required repeated parameter cannot be added after an optional parameter/)
    end

    it 'an error is raised with reference to multiple methods when called with mis-matched arguments' do
      f = create_min_function_class_disptaching_to_two_methods()
      # TODO: Bogus parameters, not yet used
      func = f.new(:closure_scope, :loader)
      expect(func.is_a?(Puppet::Functions::Function)).to be_truthy
      expect do
        func.call({}, 10, '20')
      end.to raise_error(ArgumentError, "'min' expects one of:
  (Numeric a, Numeric b)
    rejected: parameter 'b' expects a Numeric value, got String
  (String s1, String s2)
    rejected: parameter 's1' expects a String value, got Integer")
    end

    context 'an argument_mismatch handler' do
      let(:func) { create_function_with_mismatch_handler.new(:closure_scope, :loader) }

      it 'is called on matching arguments' do
        expect { func.call({}, '1') }.to raise_error(ArgumentError, "'test' It's not OK to pass a string")
      end

      it 'is not called unless arguments are matching' do
        expect { func.call({}, '1', 3) }.to raise_error(ArgumentError, "'test' expects 1 argument, got 2")
      end

      it 'is not included in a signature mismatch description' do
        expect { func.call({}, 2.3) }.to raise_error { |e| expect(e.message).not_to match(/String/) }
      end
    end

    context 'when requesting a type' do
      it 'responds with a Callable for a single signature' do
        tf = Puppet::Pops::Types::TypeFactory
        fc = create_min_function_class_using_dispatch()
        t = fc.dispatcher.to_type
        expect(t.class).to be(Puppet::Pops::Types::PCallableType)
        expect(t.param_types.class).to be(Puppet::Pops::Types::PTupleType)
        expect(t.param_types.types).to eql([tf.numeric(), tf.numeric()])
        expect(t.block_type).to be_nil
      end

      it 'responds with a Variant[Callable...] for multiple signatures' do
        tf = Puppet::Pops::Types::TypeFactory
        fc = create_min_function_class_disptaching_to_two_methods()
        t = fc.dispatcher.to_type
        expect(t.class).to be(Puppet::Pops::Types::PVariantType)
        expect(t.types.size).to eql(2)
        t1 = t.types[0]
        expect(t1.param_types.class).to be(Puppet::Pops::Types::PTupleType)
        expect(t1.param_types.types).to eql([tf.numeric(), tf.numeric()])
        expect(t1.block_type).to be_nil
        t2 = t.types[1]
        expect(t2.param_types.class).to be(Puppet::Pops::Types::PTupleType)
        expect(t2.param_types.types).to eql([tf.string(), tf.string()])
        expect(t2.block_type).to be_nil
      end
    end

    context 'supports lambdas' do
      it 'such that, a required block can be defined and given as an argument' do
        the_function = create_function_with_required_block_all_defaults().new(:closure_scope, :loader)
        result = the_function.call({}, 7) { |a,b| a < b ? a : b }
        expect(result).to eq(7)
      end

      it 'such that, a missing required block when called raises an error' do
        the_function = create_function_with_required_block_all_defaults().new(:closure_scope, :loader)
        expect do
          the_function.call({}, 10)
        end.to raise_error(ArgumentError, "'test' expects a block")
      end

      it 'such that, an optional block can be defined and given as an argument' do
        the_function = create_function_with_optional_block_all_defaults().new(:closure_scope, :loader)
        result = the_function.call({}, 4) { |a,b| a < b ? a : b }
        expect(result).to eql(4)
      end

      it 'such that, an optional block can be omitted when called and gets the value nil' do
        the_function = create_function_with_optional_block_all_defaults().new(:closure_scope, :loader)
        expect(the_function.call({}, 2)).to be_nil
      end

      it 'such that, a scope can be injected and a block can be used' do
        the_function = create_function_with_scope_required_block_all_defaults().new(:closure_scope, :loader)
        expect(the_function.call({}, 1) { |a,b| a < b ? a : b }).to eql(1)
      end
    end

    context 'provides signature information' do
      it 'about capture rest (varargs)' do
        fc = create_function_with_optionals_and_repeated
        signatures = fc.signatures
        expect(signatures.size).to eql(1)
        signature = signatures[0]
        expect(signature.last_captures_rest?).to be_truthy
      end

      it 'about optional and required parameters' do
        fc = create_function_with_optionals_and_repeated
        signature = fc.signatures[0]
        expect(signature.args_range).to eql( [2, Float::INFINITY ] )
        expect(signature.infinity?(signature.args_range[1])).to be_truthy
      end

      it 'about block not being allowed' do
        fc = create_function_with_optionals_and_repeated
        signature = fc.signatures[0]
        expect(signature.block_range).to eql( [ 0, 0 ] )
        expect(signature.block_type).to be_nil
      end

      it 'about required block' do
        fc = create_function_with_required_block_all_defaults
        signature = fc.signatures[0]
        expect(signature.block_range).to eql( [ 1, 1 ] )
        expect(signature.block_type).to_not be_nil
      end

      it 'about optional block' do
        fc = create_function_with_optional_block_all_defaults
        signature = fc.signatures[0]
        expect(signature.block_range).to eql( [ 0, 1 ] )
        expect(signature.block_type).to_not be_nil
      end

      it 'about the type' do
        fc = create_function_with_optional_block_all_defaults
        signature = fc.signatures[0]
        expect(signature.type.class).to be(Puppet::Pops::Types::PCallableType)
      end

      it 'about parameter names obtained from ruby introspection' do
        fc = create_min_function_class
        signature = fc.signatures[0]
        expect(signature.parameter_names).to eql(['x', 'y'])
      end

      it 'about parameter names specified with dispatch' do
        fc = create_min_function_class_using_dispatch
        signature = fc.signatures[0]
        expect(signature.parameter_names).to eql([:a, :b])
      end

      it 'about block_name when it is *not* given in the definition' do
        # neither type, nor name
        fc = create_function_with_required_block_all_defaults
        signature = fc.signatures[0]
        expect(signature.block_name).to eql(:block)
        # no name given, only type
        fc = create_function_with_required_block_given_type
        signature = fc.signatures[0]
        expect(signature.block_name).to eql(:block)
      end

      it 'about block_name when it *is* given in the definition' do
        # neither type, nor name
        fc = create_function_with_required_block_default_type
        signature = fc.signatures[0]
        expect(signature.block_name).to eql(:the_block)
        # no name given, only type
        fc = create_function_with_required_block_fully_specified
        signature = fc.signatures[0]
        expect(signature.block_name).to eql(:the_block)
      end
    end

    context 'supports calling other functions' do
      before(:all) do
        Puppet.push_context( {:loaders => Puppet::Pops::Loaders.new(Puppet::Node::Environment.create(:testing, []))})
      end

      after(:all) do
        Puppet.pop_context()
      end

      it 'such that, other functions are callable by name' do
        fc = Puppet::Functions.create_function('test') do
          def test()
            # Call a function available in the puppet system
            call_function('assert_type', 'Integer', 10)
          end
        end
        # initiate the function the same way the loader initiates it
        f = fc.new(:closure_scope, Puppet.lookup(:loaders).puppet_system_loader)
        expect(f.call({})).to eql(10)
      end

      it 'such that, calling a non existing function raises an error' do
        fc = Puppet::Functions.create_function('test') do
          def test()
            # Call a function not available in the puppet system
            call_function('no_such_function', 'Integer', 'hello')
          end
        end
        # initiate the function the same way the loader initiates it
        f = fc.new(:closure_scope, Puppet.lookup(:loaders).puppet_system_loader)
        expect{f.call({})}.to raise_error(ArgumentError, "Function test(): Unknown function: 'no_such_function'")
      end
    end

    context 'supports calling ruby functions with lambda from puppet' do
      before(:all) do
        Puppet.push_context( {:loaders => Puppet::Pops::Loaders.new(Puppet::Node::Environment.create(:testing, []))})
      end

      after(:all) do
        Puppet.pop_context()
      end

      before(:each) do
        Puppet[:strict_variables] = true
      end

      let(:parser) {  Puppet::Pops::Parser::EvaluatingParser.new }
      let(:node) { 'node.example.com' }
      let(:scope) { s = create_test_scope_for_node(node); s }
      let(:loader) { Puppet::Pops::Loaders.find_loader(nil) }

      it 'function with required block can be called' do
        # construct ruby function to call
        fc = Puppet::Functions.create_function('testing::test') do
          dispatch :test do
            param 'Integer', :x
            # block called 'the_block', and using "all_callables"
            required_block_param #(all_callables(), 'the_block')
          end
          def test(x)
            # call the block with x
            yield(x)
          end
        end
        # add the function to the loader (as if it had been loaded from somewhere)
        the_loader = loader
        f = fc.new({}, the_loader)
        loader.set_entry(Puppet::Pops::Loader::TypedName.new(:function, 'testing::test'), f)
        # evaluate a puppet call
        source = "testing::test(10) |$x| { $x+1 }"
        program = parser.parse_string(source, __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).at_least(:once).and_return(the_loader)
        expect(parser.evaluate(scope, program)).to eql(11)
      end
    end

    context 'reports meaningful errors' do
      let(:parser) {  Puppet::Pops::Parser::EvaluatingParser.new }

      it 'syntax error in local type is reported with puppet source, puppet location, and ruby file containing function' do
        the_loader = loader()
        here = get_binding(the_loader)
        expect do
          eval(<<-CODE, here)
            Puppet::Functions.create_function('testing::test') do
              local_types do
                type 'MyType += Array[Integer]'
              end
              dispatch :test do
                param 'MyType', :x
              end
              def test(x)
                x
              end
            end
          CODE
        end.to raise_error(/MyType \+\= Array.*<Syntax error at '\+\=' \(line: 1, column: [0-9]+\)>.*functions4_spec\.rb.*/m)
        # Note that raised error reports this spec file as the function source since the function is defined here
      end

      it 'syntax error in param type is reported with puppet source, puppet location, and ruby file containing function' do
        the_loader = loader()
        here = get_binding(the_loader)
        expect do
          eval(<<-CODE, here)
            Puppet::Functions.create_function('testing::test') do
              dispatch :test do
                param 'Array[1+=1]', :x
              end
              def test(x)
                x
              end
            end
          CODE
        end.to raise_error(/Parsing of type string '"Array\[1\+=1\]"' failed with message: <Syntax error at '\]' \(line: 1, column: [0-9]+\)>/m)
      end

    end
    context 'can use a loader when parsing types in function dispatch, and' do
      let(:parser) {  Puppet::Pops::Parser::EvaluatingParser.new }

      it 'uses return_type to validate returned value' do
        the_loader = loader()
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            dispatch :test do
              param 'Integer', :x
              return_type 'String'
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string('testing::test(10)', __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect { parser.evaluate({}, program) }.to raise_error(Puppet::Error,
          /value returned from function 'test' has wrong type, expects a String value, got Integer/)
      end

      it 'resolve a referenced Type alias' do
        the_loader = loader()
        the_loader.add_type('myalias', type_alias_t('MyAlias', 'Integer'))
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            dispatch :test do
              param 'MyAlias', :x
              return_type 'MyAlias'
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string('testing::test(10)', __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect(parser.evaluate({}, program)).to eql(10)
      end

      it 'reports a reference to an unresolved type' do
        the_loader = loader()
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            dispatch :test do
              param 'MyAlias', :x
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string('testing::test(10)', __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect { parser.evaluate({}, program) }.to raise_error(Puppet::Error, /parameter 'x' references an unresolved type 'MyAlias'/)
      end

      it 'create local Type aliases' do
        the_loader = loader()
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            local_types do
              type 'MyType = Array[Integer]'
            end
            dispatch :test do
              param 'MyType', :x
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string('testing::test([10,20])', __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect(parser.evaluate({}, program)).to eq([10,20])
      end

      it 'create nested local Type aliases' do
        the_loader = loader()
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            local_types do
              type 'InnerType = Array[Integer]'
              type 'OuterType = Hash[String,InnerType]'
            end
            dispatch :test do
              param 'OuterType', :x
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string("testing::test({'x' => [10,20]})", __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect(parser.evaluate({}, program)).to eq({'x' => [10,20]})
      end

      it 'create self referencing local Type aliases' do
        the_loader = loader()
        here = get_binding(the_loader)
        fc = eval(<<-CODE, here)
          Puppet::Functions.create_function('testing::test') do
            local_types do
              type 'Tree = Hash[String,Variant[String,Tree]]'
            end
            dispatch :test do
              param 'Tree', :x
            end
            def test(x)
              x
            end
          end
        CODE
        the_loader.add_function('testing::test', fc.new({}, the_loader))
        program = parser.parse_string("testing::test({'x' => {'y' => 'n'}})", __FILE__)
        expect(Puppet::Pops::Adapters::LoaderAdapter).to receive(:loader_for_model_object).and_return(the_loader)
        expect(parser.evaluate({}, program)).to eq({'x' => {'y' => 'n'}})
      end
    end
  end

  def create_noargs_function_class
    Puppet::Functions.create_function('test') do
      def test()
        10
      end
    end
  end

  def create_min_function_class
    Puppet::Functions.create_function('min') do
      def min(x,y)
        x <= y ? x : y
      end
    end
  end

  def create_max_function_class
    Puppet::Functions.create_function('max') do
      def max(x,y)
        x >= y ? x : y
      end
    end
  end

  def create_badly_named_method_function_class
    Puppet::Functions.create_function('mix') do
      def mix_up(x,y)
        x <= y ? x : y
      end
    end
  end

  def create_min_function_class_using_dispatch
    Puppet::Functions.create_function('min') do
        dispatch :min do
          param 'Numeric', :a
          param 'Numeric', :b
        end
      def min(x,y)
        x <= y ? x : y
      end
    end
  end

  def create_min_function_class_disptaching_to_two_methods
    Puppet::Functions.create_function('min') do
      dispatch :min do
        param 'Numeric', :a
        param 'Numeric', :b
      end

      dispatch :min_s do
        param 'String', :s1
        param 'String', :s2
      end

      def min(x,y)
        x <= y ? x : y
      end

      def min_s(x,y)
        cmp = (x.downcase <=> y.downcase)
        cmp <= 0 ? x : y
      end
    end
  end

  def create_function_with_optionals_and_repeated
    Puppet::Functions.create_function('min') do
      def min(x,y,a=1, b=1, *c)
        x <= y ? x : y
      end
    end
  end

  def create_function_with_optionals_and_repeated_via_dispatch
    Puppet::Functions.create_function('min') do
      dispatch :min do
        param 'Numeric', :x
        param 'Numeric', :y
        optional_param 'Numeric', :a
        optional_param 'Numeric', :b
        repeated_param 'Numeric', :c
      end
      def min(x,y,a=1, b=1, *c)
        x <= y ? x : y
      end
    end
  end

  def create_function_with_optionals_and_repeated_via_multiple_dispatch
    Puppet::Functions.create_function('min') do
      dispatch :min do
        param 'Numeric', :x
        param 'Numeric', :y
        optional_param 'Numeric', :a
        optional_param 'Numeric', :b
        repeated_param 'Numeric', :c
      end
      dispatch :min do
        param 'String', :x
        param 'String', :y
        required_repeated_param 'String', :a
      end
      def min(x,y,a=1, b=1, *c)
        x <= y ? x : y
      end
    end
  end

  def create_function_with_required_repeated_via_dispatch
    Puppet::Functions.create_function('min') do
      dispatch :min do
        param 'Numeric', :x
        param 'Numeric', :y
        required_repeated_param 'Numeric', :z
      end
      def min(x,y, *z)
        x <= y ? x : y
      end
    end
  end

  def create_function_with_repeated
    Puppet::Functions.create_function('count_args') do
      dispatch :count_args do
        repeated_param 'Any', :c
      end
      def count_args(*c)
        c.size
      end
    end
  end

  def create_function_with_optional_repeated
    Puppet::Functions.create_function('count_args') do
      dispatch :count_args do
        optional_repeated_param 'Any', :c
      end
      def count_args(*c)
        c.size
      end
    end
  end

  def create_function_with_required_repeated
    Puppet::Functions.create_function('count_args') do
      dispatch :count_args do
        required_repeated_param 'Any', :c
      end
      def count_args(*c)
        c.size
      end
    end
  end

  def create_function_with_inexact_dispatch
    Puppet::Functions.create_function('t1') do
      dispatch :t1 do
        param 'Numeric', :x
        param 'Numeric', :y
        repeated_param 'Numeric', :z
      end
      dispatch :t1 do
        param 'String', :x
        param 'String', :y
        repeated_param 'String', :z
      end
      def t1(first, *x)
        [first.class, *x.map {|e|e.class}]
      end
    end
  end

  def create_function_with_rq_after_opt
    Puppet::Functions.create_function('t1') do
      dispatch :t1 do
        optional_param 'Numeric', :x
        param 'Numeric', :y
      end
      def t1(*x)
        x
      end
    end
  end

  def create_function_with_rq_repeated_after_opt
    Puppet::Functions.create_function('t1') do
      dispatch :t1 do
        optional_param 'Numeric', :x
        required_repeated_param 'Numeric', :y
      end
      def t1(x, *y)
        x
      end
    end
  end

  def create_function_with_param_after_repeated
    Puppet::Functions.create_function('t1') do
      dispatch :t1 do
        repeated_param 'Numeric', :x
        param 'Numeric', :y
      end
      def t1(*x)
        x
      end
    end
  end

  def create_function_with_param_injection_regular
    Puppet::Functions.create_function('test', Puppet::Functions::InternalFunction) do
      attr_injected Puppet::Pops::Types::TypeFactory.type_of(FunctionAPISpecModule::TestDuck), :test_attr
      attr_injected Puppet::Pops::Types::TypeFactory.string(), :test_attr2, "a_string"
      attr_injected_producer Puppet::Pops::Types::TypeFactory.integer(), :serial, "an_int"

      dispatch :test do
        injected_param Puppet::Pops::Types::TypeFactory.string, :x, 'a_string'
        injected_producer_param Puppet::Pops::Types::TypeFactory.integer, :y, 'an_int'
        param 'Scalar', :a
        param 'Scalar', :b
      end

      def test(x,y,a,b)
        y_produced = y.produce(nil)
        "#{x}! #{a}, and #{b} < #{y_produced} = #{ !!(a < y_produced && b < y_produced)}"
      end
    end
  end

  def create_function_with_required_block_all_defaults
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
        # use defaults, any callable, name is 'block'
        block_param
      end
      def test(x)
        yield(8,x)
      end
    end
  end

  def create_function_with_scope_required_block_all_defaults
    Puppet::Functions.create_function('test', Puppet::Functions::InternalFunction) do
      dispatch :test do
        scope_param
        param 'Integer', :x
        # use defaults, any callable, name is 'block'
        required_block_param
      end
      def test(scope, x)
        yield(3,x)
      end
    end
  end

  def create_function_with_required_block_default_type
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
        # use defaults, any callable, name is 'block'
        required_block_param :the_block
      end
      def test(x)
        yield
      end
    end
  end

  def create_function_with_scope_param_required_repeat
    Puppet::Functions.create_function('test', Puppet::Functions::InternalFunction) do
      dispatch :test do
        scope_param
        param 'Any', :extra
        repeated_param 'Any', :the_block
      end
      def test(scope, *args)
        [scope, *args]
      end
    end
  end

  def create_function_with_required_block_given_type
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
        required_block_param
      end
      def test(x)
        yield
      end
    end
  end

  def create_function_with_required_block_fully_specified
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
        # use defaults, any callable, name is 'block'
        required_block_param('Callable', :the_block)
      end
      def test(x)
        yield
      end
    end
  end

  def create_function_with_optional_block_all_defaults
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
        # use defaults, any callable, name is 'block'
        optional_block_param
      end
      def test(x)
        yield(5,x) if block_given?
      end
    end
  end

  def create_function_with_no_parameter_dispatch
    Puppet::Functions.create_function('test') do
      dispatch :test_no_args do
      end
      dispatch :test_one_arg do
        param 'Integer', :x
      end
      def test_no_args
        0
      end
      def test_one_arg(x)
        x
      end
    end
  end

  def create_function_with_mismatch_handler
    Puppet::Functions.create_function('test') do
      dispatch :test do
        param 'Integer', :x
      end

      argument_mismatch :on_error do
        param 'String', :x
      end

      def test(x)
        yield(5,x) if block_given?
      end

      def on_error(x)
        "It's not OK to pass a string"
      end
    end
  end

  def type_alias_t(name, type_string)
    type_expr = Puppet::Pops::Parser::EvaluatingParser.new.parse_string(type_string)
    Puppet::Pops::Types::TypeFactory.type_alias(name, type_expr)
  end

  def get_binding(loader_injected_arg)
    binding
  end
end