Ajv validator undergoes major rewrite in version 7

The Ajv JavaScript validator has been fully rewritten in TypeScript as part of its version 7 release. This update follows a Mozilla Open Source Support grant that enabled the developer to overhaul the project, which sees over 100 million monthly npm downloads.

Key technical changes include the replacement of doT templates with a new code generation API that utilizes lightweight syntax trees. This optimization reduces generated code size by 10-15% compared to version 6. Additionally, the project now uses tagged template literals to generate expressions and conditions, a move intended to improve code readability and prevent accidental remote code injection vulnerabilities when handling untrusted schemas.