How to generate camel_case with json_name option?

[kanziw]

I tried 4 different options in snakeToCamel, but I cound not found for my requirement.

• camel case
• use json_name if exist.
• It works at fromJSON & toJSON

with below proto,

message EchoRequest {
  string msg = 1;
  string long_message = 2 [json_name = "long"];
}

message EchoResponse {
  string want_to_camel_case = 1;
}

with buf,

1. snakeToCamel=false

Use camel_case (in proto), I expected. sample

2. snakeToCamel=json

Use json_name, but also use camelCase too. sample

3. snakeToCamel=keys

Use snakeCase (with json_name), I expected. sample

4. snakeToCamel=json,keys

It equals snakeToCamel=json option?! sample

---

I think there is a bug in situation 2.

[stephenh]

Hi @kanziw ; sorry I'm not 100% following how ts-proto doesn't support what you're looking for; if anything "camel case", "use json_name if available", sounds like the default behavior, i.e. if you just don't set snakeToCamel at all, does that do what you want?

While looking in to this, I did discover a bug in snakeToCamel, which is that , cannot be used as a separator, b/c it's already used as a separate between different flags.

So, I'm making a change to use _ as a separate (kinda ugly but 🤷 ... cc @paralin for any good ideas?):

#648

So, I think that will fix your option 4 output. Maybe let the ^ PR land and you can re-do your test/examples with the updated code, and then let us know if there is still something missing.

I'm hoping that what you're really asking for is the default ts-proto output, which is effectively snakeToCamel=json,keys (if the user doesn't set anything), but b/c you were trying to set snakeToCamel=json,keys but there was a bug in the , parsing, that the behavior ended up being weird/undefined.

[kanziw]

(I can't English well, sorry 🙏)

Thanks for you reply. @stephenh

I bumped ts-proto version up to v1.121.5 and use keys_json as option. :) kanziw@4a78e35

---

You said,

if anything "camel case", "use json_name if available", sounds like the default behavior

But, I couldn't find any options in snakeToCamel.

I want.. with below message,

message EchoRequest {
  string msg = 1;
  string long_message = 2 [json_name = "long"]; // Important! json_name attribute is here!
  string want_to_camel_case = 3;
}

EchoRequets.fromJSON should work from

{
  "msg": "msg",
  "long": "long",
  "want_to_camel_case": "want_to_camel_case"
}

to

{
  msg: "msg",
  long_message: "long",
  want_to_camel_case: "want_to_camel_case",
}

AND EchoRequets.toJSON should work from

{
  msg: "msg",
  long_message: "long",
  want_to_camel_case: "want_to_camel_case",
}

to

{
  "msg": "msg",
  "long": "long",
  "want_to_camel_case": "want_to_camel_case"
}

---

at #648 , you said

Note that to use the json_name attribute, you'll have to use the json.

So, I expected that snakeToCamel=json option satisfied me.

This is generated stubs with json option. https://github.com/kanziw/ts-proto/blob/a28b543f6980331c05e7e4ce9d199caa7fcbd278/gen/snake-case-json/echo/v1/echo.ts#L16:L35

export const EchoRequest = {
  fromJSON(object: any): EchoRequest {
    return {
      msg: isSet(object.msg) ? String(object.msg) : "",
      long_message: isSet(object.long) ? String(object.long) : "",
      want_to_camel_case: isSet(object.wantToCamelCase)
        ? String(object.wantToCamelCase)
        : "",
    };
  },

  toJSON(message: EchoRequest): unknown {
    const obj: any = {};
    message.msg !== undefined && (obj.msg = message.msg);
    message.long_message !== undefined && (obj.long = message.long_message);
    message.want_to_camel_case !== undefined &&
      (obj.wantToCamelCase = message.want_to_camel_case);
    return obj;
  },
};

I want to use stubs like,

export const EchoRequest = {
  fromJSON(object: any): EchoRequest {
    return {
      msg: isSet(object.msg) ? String(object.msg) : "",
      long_message: isSet(object.long) ? String(object.long) : "",
-     want_to_camel_case: isSet(object.wantToCamelCase)
-       ? String(object.wantToCamelCase)
+     want_to_camel_case: isSet(object.want_to_camel_case)
+       ? String(object.want_to_camel_case)
        : "",
    };
  },

  toJSON(message: EchoRequest): unknown {
    const obj: any = {};
    message.msg !== undefined && (obj.msg = message.msg);
    message.long_message !== undefined && (obj.long = message.long_message);
-   message.want_to_camel_case !== undefined &&
-     (obj.want_to_camel_case = message.want_to_camel_case);
+   message.want_to_camel_case !== undefined &&
+     (obj.want_to_camel_case = message.want_to_camel_case);
    return obj;
  },
};

I hope to show this codes with integration test, but It's hard to me. 😢

[stephenh]

Hi @kanziw , yeah I believe what you're asking for is:

a) have toJSON/fromJSON use snake case, unless
b) jsonName is set

Per above, we historically have not done this b/c protobuf doesn't give an easy way to tell "did the user set jsonName?", b/c it always sets jsonName.

That said, I put in a hueristic in #653 that tries to detect "did the user really set jsonName or is protoc just defaulting it (to something camel cased) for us?", and based on that, will use jsonName even with snakeToCamel=false, which I believe is what you want.

[stephenh]

🎉 This issue has been resolved in version 1.121.6 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release
• v1.121.6

Your semantic-release bot 📦🚀