Modify the serialization for each element

[xuzhg]

1. add the extension methods for each element.
2. remove OpenApiV2(3)Writer
3. remove OpenApiV2(3)Serializer
4. Add some Unit test.
5. All other tests pass

[xuzhg]

@PerthCharern

[PerthCharern]

OpenApiCallbackExtensions [](start = 26, length = 25)

I like it that we are finally separating out these Serialize methods into their own classes, instead of one giant serializer.

I'm reading through this, but at first glance, I wonder this: Is it beneficial to have these as Extension methods? Have you considered putting the methods directly into the models?

[xuzhg]

:) I am working the whole morning to covert it to as you said.

[xuzhg]

The PR is almost ready.

[darrelmiller]

Sorry for missing this, I was flying all day Friday. I guess we can discuss this further at our meeting today.

[PerthCharern]

Once we have more of these tests (which I think we should in order to test the whole serialization), this literal string is going to be very distracting.

I suggest we read this from a file.

[xuzhg]

What I am thinking is that the Unit test can test every small part individually.

for example, we can test the "OpenApiTag" serialization individually, same as the "OpenApiDocument".

But, I will do a little bit small changes in the coming PR.

[PerthCharern]

That sounds like a good idea. This is fine then. I'd say we should still have at least a couple of test that verify that the overall serialization works well.

[PerthCharern]

    public bool IsV3 { get { return Version == "V3"; } set { Version = "V3"; } }

These booleans are kinda funny. I'd rather make format and version a public property with getter and setter.

---

Refers to: src/Microsoft.OpenApi.Workbench/MainModel.cs:65 in 6884b00. [](commit_id = 6884b00, deletion_comment = False)

[xuzhg]

@PerthCharern

Please take a look at #42. And Compare between #41 and #42.

for the MainModel.cs, we can leave it later when we back to the test & bench project.

[xuzhg]

As we discussed today to take the #42, so close it.