Precision lost when decode long field in browser

[k8w]

protobuf.js version:
6.7.3

Reproduction code

test.proto

syntax = "proto3";

package TestProto;

message Test {
    fixed64 value = 1;
}

generate scripts:

pbjs -t static-module -w commonjs -o Test.js test.proto
npm i protobufjs

index.js

const TestProto = require('./Test').TestProto;
const Long = require('long');
var buf = TestProto.Test.encode({value: Long.fromString("6221929103415579899")}).finish();
var dec = TestProto.Test.decode(buf);
console.log(buf);
console.log(dec.value.toString());

webpack.config.js

module.exports = {
    entry: {
        app: './index.js'
    },
    output: {
        filename: 'bundle.js',
    }
}

Result

Run in node: (works well)

<Buffer 09 fb 14 c0 ea 8d bb 58 56>
6221929103415579899

Run in browser: (wrong result)

Uint8Array(9) [9, 251, 20, 192, 234, 141, 187, 88, 86]
6221929103415580000

Notice "9899" at tail was lost!

[dcodeIO]

Is dec.value a number or a Long? This usually happens when long.js is not properly recognized.

In case of doubt, try the following before decoding anything:

var Long = ...;
protobuf.util.Long = Long;
protobuf.configure();

[k8w]

@dcodeIO in NodeJS, dec.value is Long, in browser it is number

[dcodeIO]

Then long.js isn't present / recognized in your browser build and unsafe numbers are used (see long.js for more information on why precision loss is happening). Try assigning Long explicitly as shown above prior to decoding. More information on why this is happening is available here.

[k8w]

Okay.
6.5.3 works well.

[dcodeIO]

That's strange. Basically, long.js is loaded automatically when a global require function is present, that has not been renamed, and the long module is available somewhere in the project.

[k8w]

@dcodeIO
In 6.7.3 , it will ok if modify generated js like this:

var $protobuf = require("protobufjs/minimal");

//add this
var Long = require('long');
$protobuf.util.Long = Long;
$protobuf.configure();

[dcodeIO]

You can do this in any other file as well, it's just important to do it once in your project.