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@assert

The @assert attribute provides strict validation. Failed assertions raise exceptions and exclude values from responses.

Field Assertion​

Named Assert​

class Foo {
    bar int @assert(between_0_and_10, {{ this > 0 and this < 10 }})
}

Unnamed Assert​

class Foo {
    bar int @assert({{ this > 0 and this < 10 }})
}

Array Element Assert​

class MyClass {
    my_field (string @assert(is_valid_email, {{ this|regex_match("@") }}))[]
}

Parameter Assertion​

function MyFunction(x: int @assert(between_0_and_10, {{ this > 0 and this < 10 }})) -> string {
    client "openai/gpt-4o"
    prompt #"Hello, world!"#
}

Block Assertion​

class Foo {
    bar int
    baz string
    @@assert(baz_length_limit, {{ this.baz|length < this.bar }})
}

Syntax​

@assert(name, {{ jinja_expression }})
@assert({{ jinja_expression }})  // unnamed

Behavior​

  • Failed assertions raise exceptions
  • Invalid values excluded from response
  • Multiple assertions can be stacked

The this Keyword​

  • In field attributes: this refers to the field value
  • In block attributes: this refers to the entire object

Example​

class Student {
    first_name string @assert({{ this|length > 0 }})
    last_name string @assert({{ this|length > 0 }})
    age int @check(old_enough, {{ this > 5 }})
    concentration string @assert({{ this|regex_match("[Math|Science]") }})
    @@check(age_threshold, {{ this.concentration != "calculus" or this.age > 12 }})
}

See Also​