pudu-lang-validator

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A validation package written in Pudu. Define rules for a record, run them against a value, and get back an ordered list of failures. Each failure includes a property path, message, code, severity, and application state.

The package is named @chrismichaelps/pudu-lang-validator. Its modules live under PuduLangValidator.

Example

module Example

import PuduLangValidator.Rule as Rule
import PuduLangValidator.Validator as Validator
import PuduLangValidator.Rules.Text as TextRule
import PuduLangValidator.Rules.Number as NumberRule

type Customer = { name: Str, age: Int }

fn customerValidator() -> Validator.Validator[Customer] {
  let name = Rule.build(TextRule.notEmpty(Rule.ruleFor("name", |customer: Customer| customer.name)))
  let age = Rule.build(NumberRule.greaterThanOrEqualTo(Rule.ruleFor("age", |customer: Customer| customer.age), 18))
  Validator.add(Validator.add(Validator.create(), name), age)
}

fn main() -> Int {
  let validator = customerValidator()
  let outcome = Validator.validate(&validator, Customer{name: "", age: 16})
  if outcome.isValid { 0 } else { 1 }
}

Validator.validate returns a ValidationResult. In this example, both rules fail, so outcome.isValid is false and outcome.errors has two entries in rule order. You can change a message or code on an individual check before calling Rule.build.

What it includes

Rules can run in named sets or over selected properties. For a collection, Validator.includeProperties(Validator.defaults(), ["orders[].sku"]) selects sku from every order; failures still name their original indices. Child validators keep the full path, such as orders[2].sku.

Checks can use custom messages with {PropertyName}, {PropertyPath}, and {PropertyValue}. Built-in checks also provide arguments for bounds and measured values. Use Rule.withArgument or Rule.withArgumentFrom to add your own. Rule.withSeverityFrom and Rule.withStateFrom compute failure metadata from the source and selected value.

Cross-property checks such as Comparison.equalToProperty and Ordering.greaterThanProperty take a typed selector and an explicit path for the other property. Decimal.precisionScale reserves precision - scale digits for the whole-number part. Text.matches returns a typed error if its pattern cannot be compiled; a valid pattern can appear in a failure message as {RegularExpression}.

Async runs awaited checks alongside rules lifted from Rule. Call Async.validateAsync at that boundary. Both validator types support a prevalidation decision before ordinary rules run. The Testing module offers result queries for paths, messages, codes, severity, and state.

The source mirrors record each module's behavior and design decisions.

Installing

After the package is published, add it to a Pudu project:

pudu install @chrismichaelps/pudu-lang-validator

Import the modules you need under PuduLangValidator, as in the example above.

Build from source

Install Pudu 0.1.2, then:

git clone https://github.com/chrismichaelps/pudu-lang-validator
cd pudu-lang-validator
pudu test test
pudu build src/Main.pudu -o pudu-lang-validator
./pudu-lang-validator --version

Developing

pudu check $(rg --files src test -g '*.pudu')
pudu fmt --check src test
pudu lint src test
pudu test test

The wiki vault has a design page for each package module.

License

Apache License 2.0.