Hi!

Over the last weeks I've been experimenting with Fantom, mostly very simple examples to see what it can do. So far, I like the ideas very much.

Today I tried the util::JsonOutStream functionality in util. Unfortunately, this produces invalid Json when you have (private) static or transient fields. You can also see this in the code: util::JsonOutStream.writeJsonObj (line 76) will add a comma before checking whether the field is static or transient. It should only add the comma when this check fails (not a static field and not annotated as transient).

You can also test this, using the following two classes. The test has a verifyErr around the inStream and this test is successful. When you uncomment verification part, you'll find the error.

@Serializable
class Person {
  @Transient
  private static const Str country := "United Kingdom";

  Str name;
  Str? address;
  Str? city;
  Date? birthDay := null;

  @Transient
  new make(Str name, Str address, Str city) {
    this.name = name;
    this.address = address;
    this.city = city;
  }

}

-

using util;

class JsonTest : Test {
  Void testPersonJson() {

    Person[] people := [ 
      Person("John", "Main street 55", "Silvercity"),
      Person("Sarah", "Main street 56", "Goldcity"),
      Person("Jessica", "Main street 57", "Diamondcity"),
      Person("Richard", "Main street 58", "Platinumcity"),
    ];

    File file := File(Uri.fromStr("target/persons.json"), false);
    if (!file.exists()) {
      file.create();
    }

    JsonOutStream outStream := JsonOutStream(file.out());
    outStream.writeJson(people);
    outStream.close();

    verifyErr(ParseErr#) {
      JsonInStream inStream := JsonInStream(file.in());
      Person[] parsedPeople := inStream.readJson();
      inStream.close();
    }
  }
}

The solution might simply be to swap line 76 and 77 in util::JsonOutStream. Should be checked though.

Kind regards.

Hi @kuipercm

Welcome to Fantom and thanks for reporting that problem. I was able to reproduce by tweaking the existing tests. I pushed a fix to hg - changeset.