Lyo.Validation 1.0.1

Lyo.Validation

Lyo.Validation contains reusable C# validators, fluent rule builders, validation attributes, and adapters that return structured Lyo.Result.Result<T> failures. Errors are populated through Lyo.Result.Error so callers can render Problem Details, log structurally, or aggregate into BulkResult.

Schemas are named WhereClause documents (ValidationSchema) that hosts load from an API or Lyo.Validation.Postgres. Evaluation reuses IWhereClauseService.ExplainMatch; failed nodes become errors via WhereClauseExplainResult.ToErrors.

Features

• Fluent + attributes — ValidatorBuilder<T> / PropertyValidatorBuilder<T, TProperty> and AttributeValidator<T>
• Schema documents — ValidationSchema keyed by name, optional target type, WhereClause constraints (In, NotIn, Regex, …)
• Pluggable store — IValidationSchemaStore (in-memory default; Postgres in a sibling package)
• Shared error mapping — WhereClauseExplainResult.ToErrors in Query.Models (not a Validation-local builder)

Examples

Typical usage

using Lyo.Validation;

var validator = ValidatorBuilder<CreateUserRequest>.Create()
    .RuleFor(x => x.Name)
    .NotWhiteSpace()
    .Length(2, 50)
    .RuleFor(x => x.Email)
    .Email()
    .RuleFor(x => x.Age)
    .InclusiveBetween(18, 120)
    .Build();

var result = validator.Validate(new CreateUserRequest { Name = "Matt", Email = "matt@example.com", Age = 33 });

Attribute-based validation

public sealed class CreateUserRequest {
    [NotWhiteSpace]
    [Length(2, 50)]
    public string Name { get; init; } = string.Empty;

    [Email]
    public string Email { get; init; } = string.Empty;

    [Range(18, 120)]
    public int Age { get; init; }
}

Result<CreateUserRequest> result = new CreateUserRequest { /* ... */ }.ValidateWithAttributes();

Load a WhereClause schema

services.AddLyoQueryServices();
services.AddValidation();
services.AddQueryValidationEvaluator();
// or services.AddPostgresValidationStoreFromConfiguration(configuration);

var validator = await compiler.GetAsync<CreateUserRequest>("signup.v2", ct);
var result = validator.Validate(request);

What lives here

• Fluent validator composition via ValidatorBuilder<T> and PropertyValidatorBuilder<T, TProperty> (including In / NotIn for scalar allow-lists).
• Attribute-based validation through built-in attributes such as Required, NotEmpty, NotWhiteSpace, Length, Regex, Email, Phone, Uri, and Range (in Lyo.Validation.Attributes).
• Data-driven ValidationSchema documents: a named WhereClause tree (same operators as query filters) compiled to IValidator<T> via IValidationSchemaCompiler.
• AttributeValidator<T> for reflection-driven validation across both Lyo's ValidationAttributeBase and System.ComponentModel.DataAnnotations (including IValidatableObject).
• Structured property metadata via ValidationMetadataKeys (PropertyName, AttemptedValue) attached to each failing Error.Metadata.
• Stable error codes via Lyo.Result.ValidationErrorCodes (e.g. NullValue, EmptyValue, InvalidLength, InvalidEmail, OutOfRange, ValidationFailed).

Attribute-based validation

AttributeValidator<T> reads validation attributes from T's public, instance-readable properties (compiled property getters are cached statically per T). It composes Lyo's own ValidationAttributeBase attributes with System.ComponentModel.DataAnnotations.ValidationAttribute, and — when T implements IValidatableObject — also runs Validate(ValidationContext). AttributeValidator<T>.Shared exposes a cached singleton; convenience extension value.ValidateWithAttributes() calls it.

DataAnnotations error codes are mapped onto Lyo.Result.ValidationErrorCodes (e.g. RequiredAttribute → RequiredValue, EmailAddressAttribute → InvalidEmail, RangeAttribute → OutOfRange); anything not mapped falls back to ValidationFailed.

Database-backed schemas

ValidationSchema is the wire DTO hosts PUT/GET on their own API. Constraints are a polymorphic WhereClause ($type: condition / group) using ComparisonOperatorEnum (Equals, In, NotIn, Regex, …). An instance is valid iff the query engine reports a match.

Register AddValidation() plus AddQueryValidationEvaluator() (after AddLyoQueryServices()). Persist with Lyo.Validation.Postgres (AddPostgresValidationStoreFromConfiguration). WhereClauseValidator<T> calls ExplainMatch then ToErrors — do not add a second error mapper in API code.

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Common — (direct, lyo)
• Lyo.Exceptions — (direct, lyo)
• Lyo.Query — (direct, lyo)
• Lyo.Query.Models — (direct, lyo)
• Lyo.Result — (direct, lyo)
• Microsoft.Extensions.DependencyInjection.Abstractions 10.0.5 — (direct, microsoft)
• System.ComponentModel.Annotations 5.0.0 — (direct, microsoft)
• Lyo.Cache — (transitive, lyo)
• Lyo.Compression — (transitive, lyo)
• Lyo.Encryption — (transitive, lyo)
• Lyo.Hashing — (transitive, lyo)
• Lyo.Health — (transitive, lyo)
• Lyo.KeyStore — (transitive, lyo)
• Lyo.Metrics — (transitive, lyo)
• Lyo.Streams — (transitive, lyo)
• BouncyCastle.Cryptography 2.6.2 — (transitive, third-party, netstandard2.0)
• EasyCompressor 2.1.0 — (transitive, third-party)
• Konscious.Security.Cryptography.Argon2 1.3.1 — (transitive, third-party)
• Microsoft.Bcl.AsyncInterfaces 10.0.5 — (transitive, microsoft, netstandard2.0)
• Microsoft.Extensions.Caching.Memory 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Configuration.Binder 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.DependencyInjection 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 — (transitive, microsoft)
• Microsoft.Extensions.Options.ConfigurationExtensions 10.0.5 — (transitive, microsoft)
• System.Buffers 4.6.1 — (transitive, microsoft, netstandard2.0)
• System.IO.Hashing 10.0.5 — (transitive, microsoft, net10.0)
• System.Memory 4.6.3 — (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 — (transitive, microsoft, netstandard2.0)
• System.Threading.Tasks.Extensions 4.6.3 — (transitive, microsoft, netstandard2.0)