Struct ValidationError 

pub struct ValidationError { /* private fields */ }

One or more validation failures collected during validation.

ValidationError is designed for multi-field struct validation where all fields should be checked and all violations reported together. For single-value validation, a simpler error type may be more appropriate.

Requires the alloc feature (enabled by default via std), since it is backed by Vec<Violation>.

Implementations

impl ValidationError

pub fn new(message: &'static str) -> Self

Creates a ValidationError with a single unnamed violation.

pub fn field(field: &'static str, message: &'static str) -> Self

Creates a ValidationError with a single named field violation.

pub fn empty() -> Self

Creates an empty ValidationError. Useful for building up violations.

Always check is_empty before returning this as Err. Returning an empty ValidationError is valid Rust but conveys no information to the caller.

pub fn with(self, violation: Violation) -> Self

Adds a violation and returns self for chaining.

pub fn push(&mut self, violation: Violation)

Adds a violation in place.

pub fn merge(self, other: Self) -> Self

Merges another ValidationError into this one.

pub fn require(self, condition: bool, violation: Violation) -> Self

Records violation only when condition is false, and returns self for chaining. A true condition means the rule held, so nothing is added.

Pair this with finish to express multi-field validation without the easy-to-forget final emptiness check:

use reliakit_validate::{ValidationError, Violation};

let result = ValidationError::empty()
    .require(!"".is_empty(), Violation::with_field("name", "must not be empty"))
    .require(15 >= 18, Violation::with_field("age", "must be at least 18"))
    .finish();

assert_eq!(result.unwrap_err().len(), 2);

pub fn require_field( self, condition: bool, field: &'static str, message: &'static str, ) -> Self

Like require, building the Violation from a field name and message.

pub fn finish(self) -> ValidateResult

Converts the accumulated violations into a result: Ok(()) when there are none, otherwise Err(self).

This removes the footgun of returning an empty ValidationError as an error (see empty).

pub fn violations(&self) -> &[Violation]

Returns all violations.

pub fn is_empty(&self) -> bool

Returns true if there are no violations.

pub fn len(&self) -> usize

Returns the number of violations.

Trait Implementations

impl Clone for ValidationError

fn clone(&self) -> ValidationError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ValidationError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ValidationError

Available on crate feature alloc only.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for ValidationError

impl Error for ValidationError

Available on crate feature std only.

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl Extend<Violation> for ValidationError

Available on crate feature alloc only.

fn extend<I: IntoIterator<Item = Violation>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl From<&'static str> for ValidationError

Available on crate feature alloc only.

fn from(message: &'static str) -> Self

Converts to this type from the input type.

impl From<Violation> for ValidationError

Available on crate feature alloc only.

fn from(v: Violation) -> Self

Converts to this type from the input type.

impl FromIterator<Violation> for ValidationError

Available on crate feature alloc only.

fn from_iter<I: IntoIterator<Item = Violation>>(iter: I) -> Self

Creates a value from an iterator.

impl PartialEq for ValidationError

fn eq(&self, other: &ValidationError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ValidationError