js2proto v0.1.1

js2proto

Dumb utility to convert a JSON object into a protobuf message definition

With this tool you can quickly build a spec for some random JSON. It's not 100%, and you may have to tune it by hand, but it will get you started.

install

Install this with npm i -g js2proto.

usage

js2proto takes JSON on stdin, and outputs a protobuf to stdout.

cat MYFILE.json | js2proto TypeName > typename.proto

Where

• MYFILE.json is your JSON file
• TypeName is the name of your message-type
• typename.proto is the name of the file you want to output

example

{
  "testNum": 5,
  "testString": "tester",
  "testBool": true,
  "testArray": [1,2,3,4],
  "testObj": {
    "testNum": 5,
    "testString": "tester",
    "testBool": true,
    "testArray": [1,2,3,4]
  }
}

becomes (via cat test.json | js2proto Test)

syntax = "proto3";

message TestObj {
  int32 testNum = 1;
  string testString = 2;
  bool testBool = 3;
  repeated int32 testArray = 4;
}

message Test {
  int32 testNum = 1;
  string testString = 2;
  bool testBool = 3;
  repeated int32 testArray = 4;
  TestObj testObj = 5;
}

By comparing Test with TestObject, you can infer that it's a recursive Test structure, and further tune it by hand:

syntax = "proto3";

message Test {
  int32 testNum = 1;
  string testString = 2;
  bool testBool = 3;
  repeated int32 testArray = 4;
  Test testObj = 5;
}