overrideStandardValueWriter only applied to first java.nio.file.Path valued field of bean

[jhonnen]

The overrideStandardValueWriter mechanism seems to work only for the first field of the given type for a Bean. Here's a failing test case that demonstrates the issue (can be added to ValueWriterModifierTest):

public void testMultipleFields() throws Exception {

    TestBean input = new TestBean();
    input.p1 = Paths.get("some/path");
    input.p2 = Paths.get("some/other/path");

    String json = JSON.builder()
            .register(new JacksonJrExtension() {
                @Override
                protected void register(ExtensionContext ctxt) {
                    ctxt.insertModifier(new ReaderWriterModifier() {
                        @Override
                        public ValueWriter overrideStandardValueWriter(JSONWriter writeContext, Class<?> type, int stdTypeId) {
                            if (type == Path.class) {
                                return new PathWriter();
                            }
                            return super.overrideStandardValueWriter(writeContext, type, stdTypeId);
                        }

                    });

                    ctxt.insertProvider(new ReaderWriterProvider() {
                        @Override
                        public ValueWriter findValueWriter(JSONWriter writeContext, Class<?> type) {
                            if (Path.class.isAssignableFrom(type)) {
                                return new PathWriter();
                            }
                            return super.findValueWriter(writeContext, type);
                        }
                    });
                }
            }).build().asString(input);
    assertEquals(aposToQuotes("{'p1':'some/path','p2':'some/other/path'}"), json);
}

private static class TestBean {
    public Path p1;
    public Path p2;
}

private static class PathWriter implements ValueWriter {
    @Override
    public void writeValue(JSONWriter context, JsonGenerator g, Object value) throws IOException {
        g.writeString(((Path) value).toString().replace(File.separatorChar, '/'));
    }

    @Override
    public Class<?> valueType() {
        return Path.class;
    }
}

The test fails with

junit.framework.ComparisonFailure: 
Expected :{"p1":"some/path","p2":"some/other/path"}
Actual   :{"p1":"some/path","p2":["some","other","path"]}

--> on the second Path field, the Iterable serialization wrongly has precedence over my configured writer.

[cowtowncoder]

@jhonnen That does sound like an interesting bug. Thank you for reporting!

[cowtowncoder]

I wonder if this has something to do with the fact Path is Iterable. Should not matter of course, just noting.

[cowtowncoder]

Yes, somehow detection as SER_ITERABLE caused the problem. I worked around it by exclusion so registration should work, but I think as a follow-up I will:

1. Try to see if custom serializer overrides for "simple" (i.e. recognized) types have this problem more generally (and if so, how to fix)
2. Add explicit read/write support for java.nio.file.Path, out of the box

[cowtowncoder]

Ok, looks like there is a problem that is generalizable for "simple" (recognized and supported JDK types) types like String, too. So need to figure this out.