protobufjs

import { Root, Type, Field } from 'protobufjs'; // 1. Define a .proto schema programmatically const root = new Root('my_schema_root'); const MyMessage = new Type('MyMessage') .add(new Field('name', 1, 'string')) .add(new Field('id', 2, 'int32')) .add(new Field('isActive', 3, 'bool')); root.add(MyMessage); // In a typical application, you'd load from a .proto file: // import { loadSync } from 'protobufjs'; // import { join } from 'node:path'; // const rootFromFile = loadSync(join(__dirname, 'my_service.proto')); // const MyMessageFromRoot = rootFromFile.lookupType('MyMessage'); // 2. Prepare data to be encoded const payload = { name: 'Jane Doe', id: 123, isActive: true }; // 3. Verify the payload against the schema (optional, but good for debugging) const errMsg = MyMessage.verify(payload); if (errMsg) { throw new Error(`Invalid payload: ${errMsg}`); } // 4. Create a message instance and encode it to a buffer const message = MyMessage.create(payload); const buffer = MyMessage.encode(message).finish(); console.log('Encoded buffer (hex):', buffer.toString('hex')); // 5. Decode the buffer back into a message object const decodedMessage = MyMessage.decode(buffer); console.log('Decoded message:', JSON.stringify(decodedMessage.toJSON())); // Example: decoding a message with missing fields (will use default values) const partialBuffer = MyMessage.encode(MyMessage.create({ name: 'Partial Test' })).finish(); const decodedPartial = MyMessage.decode(partialBuffer); console.log('Decoded partial message (id and isActive default):', JSON.stringify(decodedPartial.toJSON()));