Add ‎validate command to ‎kubb-cli

[younho9]

Add validate command to kubb-cli

Problem

Currently, kubb-cli does not offer a way to validate OpenAPI/Swagger specification files directly from the CLI. Users must rely on indirect validation during code generation or use external tools to check the validity of their API specs. This can delay feedback and complicate the development workflow.

Proposed Solution

Add a validate command to kubb-cli that allows users to validate their OpenAPI/Swagger files. The command should check for syntax and structural errors, and provide clear feedback (errors/warnings) to the user.

Example usage:

kubb validate --input ./openapi.yaml

Alternatives Considered

• Relying on validation during kubb generate, which mixes validation with other concerns and gives later feedback.
• Using third-party validation tools, which adds extra steps to the workflow.

Additional Context

• The validate command should support all input formats accepted by other kubb-cli commands.
• This feature would be useful for CI pipelines, pre-commit hooks, and early feedback in development.
• The command should provide actionable feedback for fixing invalid specs.

If this proposal aligns with the project's goals, I would be happy to discuss further or help with implementation!

[stijnvanhulle]

@younho9 This has been added as part of Kubb v.3.14.0.

kubb validate --input swagger.yaml as example on how to validate a Swagger/OpenAPI file.