proto3-json-serializer Fails to Serialize Repeated Fields in Array

[hardeep-qa]

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Link to the code that reproduces this issue. A link to a public Github Repository or gist with a minimal reproduction.

N/A

A step-by-step description of how to reproduce the issue, based on the linked reproduction.

proto3-json-serializer version: 2.0.2
Node.js version: v20.13.1
protobufjs version: "^7.4.0"
Operating system: Windows

Description: The proto3-json-serializer is not serializing repeated fields in arrays properly. When attempting to serialize a message with repeated fields, the resulting JSON output is missing the array data.

1. Use the following JsonPayload:

{
  "hierarchyData": {
    "articleHierarchies": [
      {
        "hierarchyId": "Z1",
        "hierarchyNode": "1093895"
      },
      {
        "hierarchyId": "Z1",
        "hierarchyNode": "109389502"
      }
    ]
  }
}

2. Serialize the message using the provided logic:

import fs from 'fs';
import path from 'path';
import protobuf from 'protobufjs';
import * as serializer from 'proto3-json-serializer';

async function loadAllProtobufSchemas(): Promise<protobuf.Root> {
  const protoDirPath = 'data/services/protos';
  const protobufRoot = new protobuf.Root();
  const protoFiles = fs.readdirSync(protoDirPath).filter((file) => file.endsWith('.proto'));

  for (const protoFile of protoFiles) {
    await protobufRoot.load(path.join(protoDirPath, protoFile));
  }
  return protobufRoot;
}

export async function createProtobufMessage(messageTypeName: string, messagePayload: any): Promise<Uint8Array> {
  const protobufRoot = await loadAllProtobufSchemas();
  const protobufMessageType = protobufRoot.lookupType(messageTypeName);
  const protobufMessage = serializer.fromProto3JSON(protobufMessageType, messagePayload)!;
  console.log('>>1', JSON.stringify(protobufMessage, null, 2));
  const encodedMessage = protobufMessageType.encode(protobufMessage).finish();
  return encodedMessage;
}

3. Observe the logs after serialization:

{
  "hierarchyData": {}
}

4. Expecting the logs after serialization:

hierarchyData: {
      articleHierarchies: [
        {
          "hierarchyId": "Z1",
          "hierarchyNode": "1093895"
        },
        {
          "hierarchyId": "Z1",
          "hierarchyNode": "109389502"
        },
     ]

A clear and concise description of what the bug is, and what you expected to happen.

Bug Description: The proto3-json-serializer is not properly serializing repeated fields in arrays. When attempting to serialize a message with repeated fields, the resulting JSON output is missing the array data.

Expected Behavior: The serialized JSON should include the articleHierarchies array with its elements, as specified in the JsonPayload.

Additional Information: Please investigate why the repeated fields in arrays are not being serialized correctly and provide a fix or workaround.

A clear and concise description WHY you expect this behavior, i.e., was it a recent change, there is documentation that points to this behavior, etc. **

The proto3-json-serializer library is designed to serialize and deserialize protobuf.js objects according to the proto3 JSON specification. According to the documentation (https://cloud.google.com/nodejs/docs/reference/proto3-json-serializer/latest/overview), the library should handle repeated fields in arrays correctly.

Please find the example proto definitions in the comments section below.

[hardeep-qa]

Article.proto

ArticleHierarchy.proto

[sofisl]

Has this been solved for you?

[hardeep-qa]

After some investigation, I found that the articleHierarchies field is case-sensitive. Using articleHierarchies (lowercase 'a') resulted in an empty object {}, while ArticleHierarchies (uppercase 'A') worked as expected. It appears the library isn't handling case sensitivity for this field correctly.

Here's a working example:

hierarchyData: {
     ArticleHierarchies: [
       {
         "hierarchyId": "Z1",
         "hierarchyNode": "1093895"
       },
       {
        "hierarchyId": "Z1",
        "hierarchyNode": "109389502"
        },
    ]
},

And here's a non-working example:

hierarchyData: {
     articleHierarchies: [
       {
         "hierarchyId": "Z1",
         "hierarchyNode": "1093895"
       },
       {
        "hierarchyId": "Z1",
        "hierarchyNode": "109389502"
        },
    ]
},