proto-parse

proto-parse is a simple utility to parse a proto file describing a Google Protocol Buffer. Look here for more information on Proto Buffers. This is yet just a simple wrapper around a parser generated by peg.js. It is optimized for proto3 files and yet does not work for proto2. This parser strictly follows the proto 3 specs from Google;

TODO

• Add proto2 support
• Do more checking, e.g. check whether userdefined type really exists.
• Check stream support in services. Documentation does not specify the syntax, so I am waiting for Google to fix this.
• Add better reserved support

Please feel free to request any feature on github.

Usage

const parse = require('proto-parse');
var data = parse(fs.readFileSync('example.proto').toString());

No options or other parameters are currently used. Just pass the string containing the proto description to the function.

Returns

The function returns an array containing the following elements.

{
	syntax: "proto3",
	content: [
		// Top Level Elements, see below
	]
}

Package

{
  "type": "package",
  "package": "MyCompany.MyPackage"
}

Service

{
	"type": "service",
	"name": "a",
	"content": [ // Containing RPCs
		...
	]
}

RPC

{
	"type": "rpc",
	"name": "MyRPC",
	"param":, ... // Containing type of param
	"returns": ... // Containing type of return value
}

Message

{
  "type": "message",
  "name": "MY_MESSAGE" // Name of the message
  "content": [ // is an array containing messages, fields, enums
     ...
  ]

}

Type

{
	"type": "userdef", // userdef, primitive or map
	"typename": "abc" // Name of the type
}

Special case map

map<int32, string> bla = 1;

results in:

{
	"type": "field",
	"typename": "map",
	"key": "int32",
	"value": "string",
	"name": "bla",
	"fieldNo": 1,
	"opts": {}
}

Example

syntax = "proto3";

message SearchRequest {
	string query = 1;
	int32 page_number = 2;
	int32 result_per_page = 3;
	message Exmpl{
		oneof test_oneof {
			string name = 4;
			SubMessage sub_message = 9;
		}
	}
	enum Corpus {
		UNIVERSAL = 0;
		WEB = 1;
		IMAGES = 2;
		LOCAL = 3;
		NEWS = 4;
		PRODUCTS = 5;
		VIDEO = 6;
	}
	Corpus corpus = 4;
	map<int32, string> bla = 1;
	repeated Exmpl results = 1;
	reserved 2, 15, 9 to 11;
}

turns into:

{
  "syntax": "proto3",
  "content": [
    {
      "type": "message",
      "name": "SearchRequest",
      "content": [
        {
          "type": "field",
          "repeated": false,
          "typename": "string",
          "name": "query",
          "fieldNo": 1,
          "opts": {}
        },
        {
          "type": "field",
          "repeated": false,
          "typename": "int32",
          "name": "page_number",
          "fieldNo": 2,
          "opts": {}
        },
        {
          "type": "field",
          "repeated": false,
          "typename": "int32",
          "name": "result_per_page",
          "fieldNo": 3,
          "opts": {}
        },
        {
          "type": "message",
          "name": "Exmpl",
          "content": [
            {
              "type": "oneof",
              "name": "test_oneof",
              "content": [
                {
                  "type": "field",
                  "typename": "string",
                  "name": "name",
                  "fieldNo": 4,
                  "opts": {}
                },
                {
                  "type": "field",
                  "typename": "SubMessage",
                  "name": "sub_message",
                  "fieldNo": 9,
                  "opts": {}
                }
              ]
            }
          ],
          "opts": {}
        },
        {
          "type": "enum",
          "name": "Corpus",
          "content": [
            {
              "type": "enumField",
              "name": "UNIVERSAL",
              "val": 0,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "WEB",
              "val": 1,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "IMAGES",
              "val": 2,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "LOCAL",
              "val": 3,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "NEWS",
              "val": 4,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "PRODUCTS",
              "val": 5,
              "opts": {}
            },
            {
              "type": "enumField",
              "name": "VIDEO",
              "val": 6,
              "opts": {}
            }
          ],
          "opts": {}
        },
        {
          "type": "field",
          "repeated": false,
          "typename": "Corpus",
          "name": "corpus",
          "fieldNo": 4,
          "opts": {}
        },
        {
          "type": "field",
          "typename": "map",
          "key": "int32",
          "value": "string",
          "name": "bla",
          "fieldNo": 1,
          "opts": {}
        },
        {
          "type": "field",
          "repeated": true,
          "typename": "Exmpl",
          "name": "results",
          "fieldNo": 1,
          "opts": {}
        }
      ],
      "opts": {}
    }
  ]
}

Changes

• v0.0.1 Initial commit.
• v0.0.2 Just fixed some bugs in the Readme file.
• v0.0.4 Fixed comment parsing
• v0.0.5 Bugfix: Fieldno with more than two digits is not correctly parsed. Added example in README.