Protobuf Practice

Edit the schema, wait for the descriptor checks, and continue when everything passes.

Progress

Exercise 6: Field Presence

6. Field Presence

Context

In proto3, a scalar field with its default value is usually omitted from the wire. For a boolean, that means a receiver cannot distinguish `false` from not set unless the field has explicit presence.

Task

Add explicit field presence tracking to the is_admin field.

Advanced > Field Presence

schema.proto

Valid Schema

syntax = "proto3";

package practice;

message UserSession {
  string username = 1;
  bool is_admin = 2;
}

EVALUATION_CHECKS

Field 'is_admin' uses the 'optional' keyword for presence.

Exercise Incomplete

Please satisfy all checks above

Basics

Write practical schemas with messages, fields, and types.

Advanced

Evolve messages without breaking deployed systems.

Binary

Decode wire-format bytes one field at a time.