Add a new C API spec for rb_error_frozen_object.

Author: nirvdrum

spec/ruby/optional/capi/exception_spec.rb

@@ -100,6 +100,15 @@
     end
   end
 
+  describe "rb_error_frozen_object" do
+    it "raises a FrozenError regardless of the object's frozen state" do
+      # The type of the argument we supply doesn't matter. The choice here is arbitrary and we only change the type
+      # of the argument to ensure the exception messages are set correctly.
+      -> { @s.rb_error_frozen_object(Hash.new) }.should raise_error(FrozenError, "can't modify frozen Hash")
+      -> { @s.rb_error_frozen_object(Array.new.freeze) }.should raise_error(FrozenError, "can't modify frozen Array")
+    end
+  end
+
   describe "rb_syserr_new" do
     it "returns system error with default message when passed message is NULL" do
       exception = @s.rb_syserr_new(Errno::ENOENT::Errno, nil)

spec/ruby/optional/capi/ext/exception_spec.c

@@ -36,6 +36,11 @@ VALUE exception_spec_rb_set_errinfo(VALUE self, VALUE exc) {
   return Qnil;
 }
 
+VALUE exception_spec_rb_error_frozen_object(VALUE self, VALUE object) {
+    rb_error_frozen_object(object);
+    return Qnil;
+}
+
 VALUE exception_spec_rb_syserr_new(VALUE self, VALUE num, VALUE msg) {
   int n = NUM2INT(num);
   char *cstr = NULL;
@@ -66,6 +71,7 @@ void Init_exception_spec(void) {
   rb_define_method(cls, "rb_exc_new3", exception_spec_rb_exc_new3, 1);
   rb_define_method(cls, "rb_exc_raise", exception_spec_rb_exc_raise, 1);
   rb_define_method(cls, "rb_set_errinfo", exception_spec_rb_set_errinfo, 1);
+  rb_define_method(cls, "rb_error_frozen_object", exception_spec_rb_error_frozen_object, 1);
   rb_define_method(cls, "rb_syserr_new", exception_spec_rb_syserr_new, 2);
   rb_define_method(cls, "rb_syserr_new_str", exception_spec_rb_syserr_new_str, 2);
   rb_define_method(cls, "rb_make_exception", exception_spec_rb_make_exception, 1);