(PUP-514) Check for slurp arguments in EPP

EPP, because it uses named parameters, does not support using slurped
(captures rest) parameters. This adds a static check to catch that being
done.

lib/puppet/pops/validation/checker4_0.rb

@@ -201,6 +201,12 @@ def check_CallNamedFunctionExpression(o)
     end
   end
 
+  def check_EppExpression(o)
+    if o.eContainer.is_a?(Puppet::Pops::Model::LambdaExpression)
+      internal_check_no_capture(o.eContainer, o)
+    end
+  end
+
   def check_MethodCallExpression(o)
     unless o.functor_expr.is_a? Model::QualifiedName
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o.functor_expr, :feature => 'function name', :container => o)
@@ -269,10 +275,10 @@ def internal_check_capture_last(o)
     end
   end
 
-  def internal_check_no_capture(o)
+  def internal_check_no_capture(o, container = o)
     o.parameters.each_with_index do |p, index|
       if p.captures_rest
-        acceptor.accept(Issues::CAPTURES_REST_NOT_SUPPORTED, p, {:container => o, :param_name => p.name})
+        acceptor.accept(Issues::CAPTURES_REST_NOT_SUPPORTED, p, {:container => container, :param_name => p.name})
       end
     end
   end

spec/unit/parser/functions/epp_spec.rb

@@ -70,6 +70,12 @@
       expect(eval_template_with_args("<%-|String $x|-%><%= $x == correct %>", 'x' => 'correct')).to eq("true")
     end
 
+    it "does not allow slurped parameters" do
+      expect do
+        eval_template_with_args("<%-|*$x|-%><%= $x %>", 'x' => 'incorrect')
+      end.to raise_error(/'captures rest' - not supported in an Epp Template/)
+    end
+
     it "raises an error when the passed value does not match the parameter's type" do
       expect do
         eval_template_with_args("<%-|Integer $x|-%><%= $x %>", 'x' => 'incorrect')