fn::validate

The fn::validate built-in function validates a value against a JSON Schema. If the value does not conform to the schema, a validation error is raised and the environment cannot be saved until the issues are resolved.

Declaration

fn::validate:
  schema: json-schema
  value: value-to-validate

Parameters

Returns

If validation passes, the original value is returned. If validation fails, an error is raised and the environment cannot be saved.

Validation errors

When a value does not conform to its schema, fn::validate raises an error that prevents the environment from being saved. This ensures configuration issues are caught before the environment is used.

Example: type mismatch

values:
  type-error:
    fn::validate:
      schema: { type: string }
      value: 42

This raises an error: expected string, got number. The environment cannot be saved until the value conforms to the schema.

Example: missing required field

values:
  missing-required:
    fn::validate:
      schema:
        type: object
        properties:
          name: { type: string }
        required: [name]
      value:
        other: "value"

This raises an error indicating that the required field name is missing. The environment cannot be saved until the required field is provided.