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#![feature(doc_cfg)] /*! # Overview The main idea is based on [Serde](::serde)'s [Serialize](serde::Serialize) and [Serializer](serde::ser::Serializer) traits. Similarly, Verify has a [Validate](Validate) trait that types can implement and decide how they should be validated, and a [Validator](Validator) trait for types that do the actual validation. [Spans](span::Span) contain information about each value during validation, with their help any deeply nested value can be identified after validation without additional lookups. There are also two higher level traits: [Verify](Verify) and [Verifier](Verifier). [Verifiers](Verifier) validate values that implement [Validate](Validate) *somehow* internally, it might involve multiple validations and even validators or none at all. [Verify](Verify) is implemented by types that can verify themselves *somehow*, it might or might not involve a [Validator](Validator), nothing is known about the validation process apart from the output. Note that validation and verification mean pretty much the same thing **in the context of this library**, the distinction is for naming purposes only. Thanks to the similarity with [Serde](::serde), validating serializable values is rather straightforward, read more about it [here](crate::serde). # Basic Usage The library itself without features doesn't do much, it only provides definitions and common traits. In order to use it you need to write or find a validator, or enable one of the implementation features of the library. There is official support only for [Schemars](https://github.com/GREsau/schemars) at the moment. This very basic example shows how to create a self-validating type with Verify and Schemars: ```edition2018 # use schemars_crate::{self as schemars, JsonSchema}; # use serde::Serialize; # use crate::Verify; #[derive(Default, Verify, Serialize, JsonSchema)] #[verify(schemars, serde)] struct ExampleStruct { example_value: i32, } let example = ExampleStruct::default(); assert!(example.verify().is_ok()); ``` */ pub mod span; #[cfg(feature = "serde")] #[doc(cfg(feature = "serde"))] pub mod serde; // Optional implementations for various crates. mod impls; // "impls" is only for code structure, it is removed // for the public API. pub use impls::*; /** Macro for deriving [Verify](Verify). # Attributes All options are set by the `verify` attribute. ## Container Attributes ### serde Use [Serde](::serde) for validation. **Options:** - spans (optional): The name of the type that provides spans, it must implement [Spans](crate::serde::Spans). By default [KeySpans](crate::serde::KeySpans) is used. **Example:** ```ignore #[verify(serde(spans = "KeySpans"))] pub struct Example { ... } ``` ### schemars Use [Schemars](::schemars_crate) schema for validation. Works only if the type implements [Serialize](serde::Serialize) and [JsonSchema](schemars_crate::JsonSchema). It also needs the `serde` to be enabled. **Example:** ```ignore #[verify(schemars, serde)] pub struct Example { ... } ``` ### verifier Provide what verifier to use. **Options:** - name: The name of the verifier type. - create (optional): How the verifier should be constructed, [Default](Default) is used if not set. - error (optional): The error type of the verifier, it might be needed when there are ambiguous complex generics that cannot be guessed by the macro. **Example:** With name only: ```ignore #[verify(verifier = "ExampleVerifier")] pub struct Example { ... } ``` Or with options: ```ignore #[verify( verifier( name = "verifiers::ExampleVerifier", create = "verifiers::get_a_new_verifier(self.config())" ) )] pub struct Example { ... } ``` ## Field Attributes Field attributes are ignored for now. */ pub use verify_macros::Verify; /// The errors returned by validators must implement this trait. /// /// The [AddAssign](core::ops::AddAssign) bound is required in order to support /// validators that return multiple errors. pub trait Error: Sized + std::error::Error + core::ops::AddAssign {} /// Validate is implemented by values that can be validate themselves /// against a given validator. pub trait Validate: span::Spanned { /// Validate self against a given validator. fn validate<V: Validator<Self::Span>>(&self, validator: V) -> Result<(), V::Error>; } /// This trait is implemented by types that validate a value internally. /// /// It is useful when the actual [Validator](Validator) is not exposed, or there /// might be more than one validations taking place for the same value. pub trait Verifier<S: span::Span> { /// The error returned by the validator. type Error: Error; /// Validate a value internally. fn verify_value<V: ?Sized + Validate<Span = S>>(&self, value: &V) -> Result<(), Self::Error>; /// Validators that support hierarchical spans might require a starting parent span. fn verify_value_with_span<V: ?Sized + Validate<Span = S>>( &self, value: &V, _span: Option<V::Span>, ) -> Result<(), Self::Error> { self.verify_value(value) } } /// This trait is implemented by types that can validate themselves. pub trait Verify { /// The error returned by the validator. type Error: Error; /// Validate self internally. fn verify(&self) -> Result<(), Self::Error>; } /// Values that implement [Validate](Validate) can validate themselves against /// types that implement this trait. /// /// It is modelled after Serde [Serializer](serde::ser::Serializer), and works in a very similar fashion. pub trait Validator<S: span::Span>: Sized { /// The error returned by the validator. type Error: Error; /// The type returned for validating sequences. /// /// The span type and error must match the Validator's. type ValidateSeq: ValidateSeq<S, Error = Self::Error>; /// The type returned for validating maps. /// /// The span type and error must match the Validator's. type ValidateMap: ValidateMap<S, Error = Self::Error>; /// Set the span for the current value that is being validated. /// /// In some cases this is needed to ensure that the validator returns /// the correct span in its errors. fn with_span(self, span: Option<S>) -> Self; /// Validate a bool value. fn validate_bool(self, v: bool) -> Result<(), Self::Error>; /// Validate an i8 value. fn validate_i8(self, v: i8) -> Result<(), Self::Error>; /// Validate an i16 value. fn validate_i16(self, v: i16) -> Result<(), Self::Error>; /// Validate an i32 value. fn validate_i32(self, v: i32) -> Result<(), Self::Error>; /// Validate an i64 value. fn validate_i64(self, v: i64) -> Result<(), Self::Error>; /// Validate an i128 value. fn validate_i128(self, v: i128) -> Result<(), Self::Error>; /// Validate an u8 value. fn validate_u8(self, v: u8) -> Result<(), Self::Error>; /// Validate an u16 value. fn validate_u16(self, v: u16) -> Result<(), Self::Error>; /// Validate an u32 value. fn validate_u32(self, v: u32) -> Result<(), Self::Error>; /// Validate an u64 value. fn validate_u64(self, v: u64) -> Result<(), Self::Error>; /// Validate an u128 value. fn validate_u128(self, v: u128) -> Result<(), Self::Error>; /// Validate an f32 value. fn validate_f32(self, v: f32) -> Result<(), Self::Error>; /// Validate an f64 value. fn validate_f64(self, v: f64) -> Result<(), Self::Error>; /// Validate a single char value. fn validate_char(self, v: char) -> Result<(), Self::Error>; /// Validate a string value. fn validate_str(self, v: &str) -> Result<(), Self::Error>; /// Validate slice of bytes. fn validate_bytes(self, v: &[u8]) -> Result<(), Self::Error>; /// Validate a [None](Option::None) value. fn validate_none(self) -> Result<(), Self::Error>; /// Validate a [Some](Option::Some) value. fn validate_some<V>(self, value: &V) -> Result<(), Self::Error> where V: ?Sized + Validate<Span = S>; /// Validate an empty tuple `()`. fn validate_unit(self) -> Result<(), Self::Error>; /// Validate a zero-sized struct. fn validate_unit_struct(self, name: &'static str) -> Result<(), Self::Error>; /// Validate a unit enum variant. fn validate_unit_variant( self, name: &'static str, variant_index: u32, variant: &'static str, ) -> Result<(), Self::Error>; /// Validate a sequence. fn validate_seq(self, len: Option<usize>) -> Result<Self::ValidateSeq, Self::Error>; /// Validate a map. fn validate_map(self, len: Option<usize>) -> Result<Self::ValidateMap, Self::Error>; /// Validate a tag for a map value. /// /// This exists in order to support Serde's "externally tagged" types, /// for example `{ "TAG": ... }`. fn validate_tag<V>(&mut self, tag: &V) -> Result<(), Self::Error> where V: ?Sized + Validate<Span = S> + ToString; } /// Type returned by [validate_seq](Validator::validate_seq). pub trait ValidateSeq<S: span::Span> { /// The error returned by the validator. type Error: std::error::Error; /// Set the span for the current value that is being validated. /// /// In some cases this is needed to ensure that the validator returns /// the correct span in its errors. fn with_span(&mut self, span: Option<S>) -> &mut Self; /// Validate an element in the sequence. fn validate_element<V>(&mut self, value: &V) -> Result<(), Self::Error> where V: ?Sized + Validate<Span = S> + core::hash::Hash; /// End the sequence. fn end(self) -> Result<(), Self::Error>; } /// Type returned by [validate_map](Validator::validate_map). pub trait ValidateMap<S: span::Span> { /// The error returned by the validator. type Error: std::error::Error; /// Set the span for the current value that is being validated. /// /// In some cases this is needed to ensure that the validator returns /// the correct span in its errors. fn with_span(&mut self, span: Option<S>) -> &mut Self; /// Validate a key in the map. fn validate_key<V>(&mut self, key: &V) -> Result<(), Self::Error> where V: ?Sized + Validate<Span = S>; /// Validate a key in the map. /// /// This method guarantees that the key is a string /// or has a string representation. fn validate_string_key<V>(&mut self, key: &V) -> Result<(), Self::Error> where V: ?Sized + Validate<Span = S> + ToString; /// Validate a map entry. fn validate_value<V: ?Sized>(&mut self, value: &V) -> Result<(), Self::Error> where V: Validate<Span = S>; /// Validate an entry (key and value). fn validate_entry<K: ?Sized, V: ?Sized>( &mut self, key: &K, value: &V, ) -> Result<(), Self::Error> where K: Validate<Span = S>, V: Validate<Span = S>, { self.validate_key(key)?; self.validate_value(value) } /// Validate an entry (key and value). /// /// This method guarantees that the key is a string /// or has a string representation. fn validate_string_entry<K, V>(&mut self, key: &K, value: &V) -> Result<(), Self::Error> where K: ?Sized + Validate<Span = S> + ToString, V: ?Sized + Validate<Span = S>, { self.validate_string_key(key)?; self.validate_value(value) } /// Some [Validate](Validate) implementors can convert map keys to strings. /// With this method redundant conversions can be avoided. fn string_key_required(&self) -> bool { false } /// End the map. fn end(self) -> Result<(), Self::Error>; }