Validate JSON against a protobuf-like schema

Q: Validate JSON against a protobuf-like schema

This question evaluates schema validation and data-typing skills, including understanding of JSON primitive types, recursive message structures, and conformance to a protobuf-like schema with required and optional fields.

Q: How do I approach Coding & Algorithms interview questions?

Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

Q: What difficulty level is this interview question?

This is a medium difficulty Coding & Algorithms question, commonly asked during Technical Screen rounds at Applied.

Q: What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Applied during technical interviews.

Question

Loading...

You are given a simplified protobuf-like schema definition and a JSON value. Determine whether the JSON conforms to the schema.

Schema model

A schema contains named message types .
Each message type contains fields . Each field has:
- name (string)
- type (one of: int , float , bool , string , or another message type name)
- optional (boolean)

Assume:

The JSON root is an object corresponding to a specified root message type.
A required field ( optional = false ) must be present.
An optional field may be missing.
If a field is present, its JSON value must match the expected type:
- int : JSON number with no fractional part
- float : JSON number (integer values are allowed)
- bool : JSON boolean
- string : JSON string
- message type: JSON object that recursively validates against that message
Extra JSON keys not in the schema make the JSON invalid.

Task

Implement isValid(schema, rootTypeName, jsonValue) -> bool.

Constraints

Up to ~10^4 total fields across all message types.
Message nesting depth is bounded (e.g., ≤ 50).

Example

Schema:

User { id:int (required), name:string (optional) }

Valid JSON: { "id": 1 } Invalid JSON: { "name": "a" } (missing required id) Invalid JSON: { "id": 1, "age": 10 } (unknown field age)

Validate JSON against a protobuf-like schema

Quick Overview

Schema model

Task

Constraints

Example

Comments (0)