Struct ValidationError

Source

pub struct ValidationError {
    pub violations: SmallVec<[Violation; 4]>,
}

Expand description

Represents a collection of validation violations.

This type aggregates all validation errors that occur during validation of a domain object. It supports merging errors from multiple fields and nested structures.

§Examples

use domainstack::{ValidationError, Path};

let mut err = ValidationError::new();
err.push("email", "invalid_email", "Invalid email format");
err.push("age", "out_of_range", "Must be between 18 and 120");

assert_eq!(err.violations.len(), 2);
assert!(!err.is_empty());

§Nested Errors

use domainstack::{ValidationError, Path};

let mut child_err = ValidationError::new();
child_err.push("value", "invalid_email", "Invalid email format");

let mut parent_err = ValidationError::new();
parent_err.merge_prefixed("email", child_err);

// Error path becomes "email.value"
assert_eq!(parent_err.violations[0].path.to_string(), "email.value");

Fields§

§violations: SmallVec<[Violation; 4]>

Implementations§

Source §

pub fn single( path: impl Into<Path>, code: &'static str, message: impl Into<String>, ) -> Self

Source

pub fn push( &mut self, path: impl Into<Path>, code: &'static str, message: impl Into<String>, )

Source

pub fn extend(&mut self, other: ValidationError)

Source

pub fn merge_prefixed( &mut self, prefix: impl Into<Path>, other: ValidationError, )

Merges violations from another error with a path prefix.

This is optimized to avoid cloning the prefix for each violation. The prefix segments are collected once and reused for all violations.

§Performance

Old: O(n) prefix clones where n = number of violations
New: O(1) prefix collection + O(n * m) segment clones where m = avg segments per path

For typical use cases (< 10 violations), this optimization reduces allocations significantly.

Source

pub fn field_errors_map(&self) -> BTreeMap<String, Vec<String>>

👎Deprecated since 0.5.0: Use field_violations_map() instead to preserve error codes and metadata. This method only returns messages and loses important error information.

Returns a map of field paths to error messages.

⚠️ Warning: This method only returns messages and loses error codes and metadata. For complete error information including codes (needed for proper error classification, client-side handling, and internationalization), use field_violations_map() instead.

§Examples

use domainstack::ValidationError;

let mut err = ValidationError::new();
err.push("email", "invalid_format", "Invalid email format");
err.push("email", "too_long", "Email too long");

let map = err.field_errors_map();
assert_eq!(map.get("email").unwrap().len(), 2);
// Note: Error codes "invalid_format" and "too_long" are lost!

Source

pub fn field_violations_map(&self) -> BTreeMap<String, Vec<&Violation>>

Source

pub fn prefixed(self, prefix: impl Into<Path>) -> Self

Returns a new ValidationError with all paths prefixed.

§Performance

This method is optimized to collect prefix segments once and reuse them, avoiding repeated cloning of the prefix path.

Source

pub fn map_messages<F>(self, f: F) -> Self
where F: Fn(String) -> String,

Transform all violation messages using the provided function.

This is useful for internationalization (i18n), message formatting, or any other message transformation needs.

§Examples

use domainstack::ValidationError;

let mut err = ValidationError::new();
err.push("email", "invalid", "Invalid email");
err.push("age", "too_young", "Must be 18+");

// Add prefix to all messages
let err = err.map_messages(|msg| format!("Error: {}", msg));

assert_eq!(err.violations[0].message, "Error: Invalid email");
assert_eq!(err.violations[1].message, "Error: Must be 18+");

§Internationalization Example

use domainstack::ValidationError;

let mut err = ValidationError::new();
err.push("email", "invalid_email", "Invalid email format");

// Translate messages based on error code
let err = err.map_messages(|msg| {
    // In a real app, this would use error codes for translation
    "Formato de email inválido".to_string()
});

assert_eq!(err.violations[0].message, "Formato de email inválido");

Source

pub fn filter<F>(self, f: F) -> Self
where F: Fn(&Violation) -> bool,

Filter violations based on a predicate.

This is useful for removing certain types of errors based on custom criteria.

§Examples

use domainstack::ValidationError;

let mut err = ValidationError::new();
err.push("email", "warning", "Email format questionable");
err.push("age", "invalid", "Age is required");
err.push("name", "warning", "Name seems unusual");

// Remove all warnings, keep only errors
let err = err.filter(|v| v.code != "warning");

assert_eq!(err.violations.len(), 1);
assert_eq!(err.violations[0].code, "invalid");