TypeScript protobufs

tspb.ts

export type FieldDesc<T, F> = {
  id: number,
  getter: (instance: T) => F,
  setter: (instance: T, value: F) => void,
  desc?: MessageDesc<F>
}

export class MessageDesc<T> {
  constructor(private fields: FieldDesc<T, any>[]) {}

  toJson(instance: T): any {
    const result = Object.create(null);
    for (const field of this.fields) {
      const value = field.getter(instance);
      if (value != null) {
        result[field.id] = value;
      }
    }
    return result;
  }
  fromJson(json: any): T {
    const result: T = Object.create(null);
    for (const field of this.fields) {
      const value = json[field.id];
      if (value != null) {
        field.setter(result, value);
      }
    }
    return result;
  }
  toJspb(instance: T): any { throw 'TODO'; }
  fromJspb(instance: any): T { throw 'TODO'; }
}

tspb_test.ts

import SearchResult from 'goog:proto.javascript.angular2.codelab.protos.SearchResult';

import {MessageDesc} from './tspb';


export type TsPbSearchResult = {
  etag?: string, // 201
  id?: TsPbResourceId, // 1
  kind?: string, // 200
  snippet?: TsPbSearchResultSnippet, // 2
  statistics?: TsPbVideoStatistics, // 202
};
export type TsPbResourceId = {};
export type TsPbSearchResultSnippet = {};
export type uint64 = number;
export type TsPbVideoStatistics = {
    commentCount?: uint64, // 5
    dislikeCount?: uint64, // 3
    favoriteCount?: uint64, // 4
    likeCount?: uint64, // 2
    viewCount?: uint64, // 1
};

export const TsPbVideoStatistics = new MessageDesc<TsPbVideoStatistics>([
  {id: 1, getter: i => i.viewCount, setter: (i, v) => i.viewCount = v},
  {id: 2, getter: i => i.likeCount, setter: (i, v) => i.likeCount = v},
  {id: 3, getter: i => i.dislikeCount, setter: (i, v) => i.dislikeCount = v},
  {id: 4, getter: i => i.favoriteCount, setter: (i, v) => i.favoriteCount = v},
  {id: 5, getter: i => i.commentCount, setter: (i, v) => i.commentCount = v},
]);
export const TsPbResourceId = new MessageDesc<TsPbResourceId>([]);
export const TsPbSearchResultSnippet = new MessageDesc<TsPbSearchResultSnippet>([]);
export const TsPbSearchResult = new MessageDesc<TsPbSearchResult>([
  {id: 201, getter: i => i.etag, setter: (i, v) => i.etag = v},
  {id: 1, getter: i => i.id, setter: (i, v) => i.id = v, desc: TsPbResourceId},
  {id: 200, getter: i => i.kind, setter: (i, v) => i.kind = v},
  {id: 2, getter: i => i.snippet, setter: (i, v) => i.snippet = v, desc: TsPbSearchResultSnippet},
  {id: 202, getter: i => i.statistics, setter: (i, v) => i.statistics = v, desc: TsPbVideoStatistics},
]);

var res: TsPbSearchResultSnippet = {

}
//new MessageDesc<
// export const TsPbSearchResult = new MessageDesc<TsPbSearchResult>([], SearchResult.deserialize);

/*
message Foo {
  optional string bar = 1;
  repeated string bars = 2;
}
*/

type Sub = {
  s?: string
};
const Sub = new MessageDesc<Sub>([
  {id: 0, getter: (i: Sub) => i.s, setter: (i: Sub, v: string) => i.s = v},
]);
type Foo = {
  bar?: string,
  bars?: string[],
  sub?: Sub,
};
const Foo = new MessageDesc<Foo>([
  {
    id: 0, getter: i => i.bar, setter: (i, v) => i.bar = v
  },
  {
    id: 1, getter: i => i.bars, setter: (i, v) => i.bars = v
  },
  {
    id: 2, getter: i => i.sub, setter: (i, v) => i.sub = v, desc: Sub
  },
]);

var f: Foo = {bar: "a", bars: []};

expect(Foo.toJson(f)).toBe({1:"a", 2:["a", "b"]});