File System Structure Validator

Build a runtime type validator for a simplified file system structure where directories can contain files, and files reference their parent directories. This creates a mutually recursive relationship between the two types.

Requirements

Create runtime validators for two interdependent types:

1. Directory: An object with:

   • type: Always the literal value "directory"
   • name: A string
   • contents: An array of File objects (can be empty)

2. File: An object with:

   • type: Always the literal value "file"
   • name: A string
   • parentDir: A Directory object

Your validators should:

• Validate runtime data and return success or failure results
• Extract TypeScript types from the runtime validators

Test Cases

• Validates a directory with one file that references the directory @test
• Validates a directory with multiple files @test
• Validates an empty directory @test
• Rejects invalid directory structure @test

Dependencies { .dependencies }

io-ts { .dependency }

Provides runtime type validation and decoding capabilities.

@satisfied-by