Test nqp::setinvokespec with invocationHandler.

Author: pmurias

t/nqp/70-invokespec.t

@@ -1,4 +1,4 @@
-plan(4);
+plan(11);
 class Foo {
     has $!here_we_keep_the_code_ref;
     has $!other_place_we_could_keep_the_code_ref_in;
@@ -30,3 +30,37 @@ class Baz {
 
 ok(nqp::isinvokable(Foo) == 1, "nqp::isinvokable works on objects that have a set invokespec");
 ok(nqp::isinvokable(Baz) == 0, "nqp::isinvokable works on objects that don't have a set invokespec");
+
+class Second {
+    has $!attr;
+    has $!ret;
+    method attr() {$!attr}
+    method ret() {$!ret}
+}
+
+my $called;
+my $called_arg;
+my $called_name;
+
+nqp::setinvokespec(Second, nqp::null(), nqp::null_s(), -> $invokee, $arg1, :$named {
+    $called := $invokee;
+    $called_arg := $arg1;
+    $called_name := $named;
+    $invokee.ret;
+});
+
+my $second := Second.new(attr => "hello", ret => "peculiar");
+
+ok($second("world", :named('brave new')) eq 'peculiar','correct value from invocation');
+
+ok($called.attr eq 'hello', 'got right invokee to invocation handler');
+ok($called_arg eq 'world', 'got positional');
+ok($called_name eq 'brave new', 'got named');
+
+ok(nqp::isinvokable($second) == 1, "nqp::isinvokable on object with 2nd form of setinvokespec");
+
+my $differently := Second.new(attr => "hello", ret => "not yet again");
+
+my @args := nqp::list("again");
+ok($differently(|@args) eq "not yet again", "calling with slurpy args");
+ok($called_arg eq 'again', "...and got right arg");