nested structs aren't marshaled properly if naming convention set

[shdunning]

One of the cool features of this library is that we can set field naming strategy like so...

extra.SetNamingStrategy(extra.LowerCaseWithUnderscores)

...however it does not work correctly for nested structs. Consider the following:

type Foo struct {
	Bar struct {
		Thing1 string
		Thing2 string
	}
}

We'd expect a Foo struct to get it's Foo.Bar.Thing1 and Foo.Bar.Thing2 marshaled into json fields foo.bar.thing1 and foo.bar.thing2 but only one of the fields actually gets marshaled correctly (foo.bar.thing1 in this case).

[sai-g]

The following is the marshaled JSON output for the struct provided in the issue

// go version go1.10.2
output, err := jsoniter.Marshal(Foo{})
should.Equal(`{"bar":{"thing1":"","thing2":""}}`, string(output))

foo := &Foo{}
foo.Bar.Thing1 = "Thing1"
foo.Bar.Thing2 = "Thing2"
output1, err1 := jsoniter.Marshal(foo)
should.Equal(`{"bar":{"thing1":"Thing1","thing2":"Thing2"}}`, string(output1))

Please provide an example which would help us to replicate this

[shdunning]

@sai-g yeah, i can't seem to reproduce it now either. It might have something to do with my work in PR #275, because I noticed when I use those changes omitempty does not behave as expected. Consider the following:

type Foo struct {
	Id  int64
	Token string `json:"omitempty"`
	Ignore int64 `json:"-"`

	Bar struct {
		Thing1 string
		Thing2 string
	}
}

func TestMarshal(t *testing.T) {
	extra.SupportPrivateFields()
	extra.SetNamingStrategy(extra.LowerCaseWithUnderscores)

	should := require.New(t)
	output, _ := jsoniter.Marshal(Foo{})
	should.Equal(`{"id":0,"bar":{"thing1":"","thing2":""}}`, string(output))

	foo := &Foo{}
	foo.Id = int64(1)
	foo.Bar.Thing1 = "one"
	foo.Bar.Thing2 = "two"
	output1, _ := jsoniter.Marshal(foo)
	should.Equal(`{"id":1,"bar":{"thing1":1,"thing2":2}}`, string(output1))
}

Output:

=== RUN   TestMarshal
--- FAIL: TestMarshal (0.00s)
        Error Trace:    json_iterator_marshal_test.go:32
	Error:      	Not equal:
	            	expected: "{\"id\":0,\"bar\":{\"thing1\":\"\",\"thing2\":\"\"}}"
	            	received: "{\"id\":0,\"omitempty\":\"\",\"bar\":{\"thing1\":\"\",\"thing2\":\"\"}}"
FAIL
exit status 1
FAIL	examples	0.034s

[shdunning]

Closing this for now.