stacks-validation

name	stacks-validation
description	Use when implementing validation in Stacks — type guards (isString, isNumber, isBoolean, isObject, isArray, isFunction, etc.), numeric checks (isPositive, isEven, isInteger), the schema builder for model attribute validation, or request validation. Covers @stacksjs/validation.
license	MIT
compatibility	Bun >= 1.3.0, TypeScript
allowed-tools	Read Edit Write Bash Grep Glob

Stacks Validation

Key Paths

• Core package: storage/framework/core/validation/src/
• Package: @stacksjs/validation

Architecture

The index.ts re-exports from multiple sources:

// Re-export everything from the validation library
export * from '@stacksjs/ts-validation'

// Local modules
export * from './reporter'    // error reporting
export * from './validator'   // model/custom validation
export { schema } from './schema'  // schema builder instance

// Type guard functions defined directly in index.ts
export function isString(value: unknown): value is string
export function isNumber(value: unknown): value is number
export function isBoolean(value: unknown): value is boolean
export function isObject(value: unknown): value is Record<string, unknown>
export function isArray(value: unknown): value is unknown[]
export function isFunction(value: unknown): value is Function
export function isUndefined(value: unknown): value is undefined
export function isNull(value: unknown): value is null
export function isNullOrUndefined(value: unknown): value is null | undefined

Additional type guards are in is.ts (but not directly imported by index.ts -- available via separate import).

Type Guards (index.ts)

Basic type guards with TypeScript type narrowing:

import { isString, isNumber, isBoolean, isObject, isArray, isFunction } from '@stacksjs/validation'

isString('hello')          // true   -- typeof value === 'string'
isNumber(42)               // true   -- typeof value === 'number' && !Number.isNaN(value)
isNumber(NaN)              // FALSE  -- NaN is explicitly excluded
isBoolean(true)            // true   -- typeof value === 'boolean'
isObject({})               // true   -- typeof === 'object' && !== null && !Array.isArray
isObject([])               // FALSE  -- arrays are excluded
isObject(null)             // FALSE  -- null is excluded
isArray([])                // true   -- Array.isArray()
isFunction(() => {})       // true   -- typeof value === 'function'
isUndefined(undefined)     // true
isNull(null)               // true
isNullOrUndefined(null)    // true
isNullOrUndefined(undefined) // true

Extended Type Guards (is.ts)

Additional guards using getTypeName() from @stacksjs/types and toString() from @stacksjs/strings:

isDef(value)                // true if typeof value !== 'undefined'
isMap(new Map())            // true  -- toString check '[object Map]'
isSet(new Set())            // true  -- toString check '[object Set]'
isPromise(Promise.resolve()) // true -- toString check '[object Promise]'
isSymbol(Symbol())          // true
isDate(new Date())          // true
isRegExp(/test/)            // true
isWindow(globalThis)        // true in browser -- toString check '[object Window]'
isPrimitive(42)             // true (string, number, boolean, null, undefined, symbol)
isPrimitive({})             // false

// Environment detection
isBrowser: boolean          // typeof window !== 'undefined'
isServer: boolean           // typeof document === 'undefined'

Numeric Checks (is.ts)

isInteger(42)               // true   -- Number.isInteger()
isInteger(42.0)             // true   -- 42.0 is an integer in JS
isFloat(3.14)               // true   -- isNumber && !Number.isInteger
isFloat(42)                 // false

isPositive(5)               // true   -- > 0
isNegative(-5)              // true   -- < 0
isEven(4)                   // true   -- % 2 === 0
isOdd(3)                    // true   -- % 2 !== 0

// Classification functions (return string, not boolean)
isEvenOrOdd(4)              // 'even'
isEvenOrOdd(3)              // 'odd'
isEvenOrOdd('not a number') // 'odd'  -- non-numbers default to 'odd'

isPositiveOrNegative(5)     // 'positive'
isPositiveOrNegative(-5)    // 'negative'
isPositiveOrNegative('x')   // 'negative'  -- non-numbers default to 'negative'

isIntegerOrFloat(42)        // 'integer'
()      
()       

Schema Builder (schema.ts)

The schema object is an instance of ValidationInstance from @stacksjs/ts-validation. It provides fluent validators for model attribute definitions.

import { schema } from '@stacksjs/validation'

Available Schema Types

// String types
schema.string()                    // StringValidatorType
schema.string().minLength(2)       // chain: min length
schema.string().maxLength(100)     // chain: max length
schema.string().email()            // chain: must be email
schema.string().url()              // chain: must be URL
schema.string().matches(/pattern/) // chain: regex match
schema.string().equals('exact')    // chain: exact match
schema.string().alphanumeric()     // chain: alphanumeric only
schema.string().alpha()            // chain: letters only
schema.string().numeric()          // chain: numeric string
schema.string().custom(fn, msg)    // chain: custom validator
schema.text()                      // TextValidatorType (extends StringValidatorType)

// Number types
schema.number()                    // NumberValidatorType
schema.number().min().()    
schema.()                    
schema.()                   
schema.()                  
schema.()                     
schema.()                    
schema.()                   


schema.()                   


schema.([, , ])  


schema.()                      
schema.()                  
schema.()                 
schema.()               
schema.()                      
schema.()                      


schema.()                    
schema.()                      


schema.()                      


schema.()                  


schema.<T>()                  


schema.<T>(shapeSchema?)     


schema.<T>(validationFn, message)  

Model Attribute Usage

Schema validators are used in defineModel() attribute validation:

import { defineModel } from '@stacksjs/config'
import { schema } from '@stacksjs/validation'

export default defineModel({
  attributes: {
    name: {
      validation: {
        rule: schema.string().minLength(2).maxLength(100),
        message: {
          minLength: 'Name must be at least 2 characters',
          maxLength: 'Name cannot exceed 100 characters',
        }
      }
    },

    email: {
      validation: {
        rule: schema.string().email(),
        message: {
          email: 'Please provide a valid email address',
        }
      }
    },

    price: {
      validation: {
        rule: schema.number().min(1),
        message: {
          min: 'Price must be at least 1',
        }
      }
    },

    status: {
      validation: {
        rule: schema.enum(['active', 'inactive', 'archived']),
        message: {
          : ,
        }
      }
    },

    : {
      : {
        : schema.().(),
        : {
          : ,
        }
      }
    },
  }
})

Model Validation (validator.ts)

validateField(modelFile, params)

Validates request data against a model's attribute rules. Used internally by the framework for API request validation.

import { validateField } from '@stacksjs/validation'

// Loads model file, extracts validation rules, validates params
const result = await validateField('User', { name: 'John', email: '[e-mail]' })

Behavior:

1. Finds the model file by name in user models or framework defaults
2. Extracts validation rules from model attributes
3. Converts attribute names to snake_case for validation
4. Sets custom error messages via MessageProvider
5. Validates using schema.object(ruleObject).validate(params)
6. Throws HttpError(422) with error JSON on validation failure
7. Throws HttpError(404) if model not found
8. Skips validation for attributes with default values unless isRequired is true

customValidate(attributes, params)

Validates request data against custom attribute rules (not tied to a model):

import { customValidate } from '@stacksjs/validation'

const result = await customValidate({
  email: {
    rule: schema.string().email(),
    message: { email: 'Invalid email' }
  },
  age: {
    rule: schema.number().min(18),
    message: { min: 'Must be at least 18' }
  }
}, requestData)

Uses schema.object().shape(ruleObject) for validation.

isObjectNotEmpty(obj)

isObjectNotEmpty({})            // false
isObjectNotEmpty({ a: 1 })      // true
isObjectNotEmpty(undefined)     // false

Error Reporter (reporter.ts)

Simple error accumulator for validation:

import { reportError, getErrors } from '@stacksjs/validation'

reportError([{ message: 'Invalid', value: '', field: 'email' }])
const errors = getErrors()   // returns accumulated MessageObject[]

Interface: { message: string, value: string, field: string }

Error Reporter Contract (from rules.ts)

VineJS-inspired types for the validation pipeline:

interface FieldContext {
  value: unknown
  data: any              // top-level object under validation
  meta: Record<string, any>
  mutate: (newValue: any, field: FieldContext) => void
  report: ErrorReporterContract['report']
  isValid: boolean
  isDefined: boolean
  wildCardPath: string   // nested pointer, '*' for array members
  parent: any
  name: string | number
  isArrayMember: boolean
}

interface ErrorReporterContract {
  hasErrors: boolean
  createError: () => Error
  report: (message: string, rule: string, field: FieldContext, args?: Record<string, >) => 
}

Re-exports from @stacksjs/ts-validation

The package re-exports everything from @stacksjs/ts-validation, which includes:

• v and schema -- the validation instance
• validator -- the validator library (default export from lib)
• MessageProvider, setCustomMessages -- custom message handling
• All type definitions (ValidatorType, StringValidatorType, NumberValidatorType, etc.)
• Configuration utilities

Validation Types (types/index.ts)

Local type definitions:

interface ValidationResult {
  valid: boolean
  errors?: Array<{ message: string }>
}

interface ValidationRule {
  validate: (value: unknown) => ValidationResult
}

type ValidationBoolean = ValidationRule
type ValidationEnum = ValidationRule
type ValidationNumber = ValidationRule
type ValidationString = ValidationRule

Gotchas

• isNumber() in index.ts returns FALSE for NaN -- this differs from typeof NaN === 'number'
• isObject() in index.ts excludes arrays and null -- isObject([]) is false
• isObject() in is.ts uses toString() check ([object Object]) which also excludes arrays/null but through a different mechanism
• isPrimitive() includes null and undefined (6 primitive types: string, number, boolean, null, undefined, symbol)
• Numeric classification functions (isEvenOrOdd, etc.) return string defaults for non-numbers rather than throwing
• Schema validators map to database column types -- schema.integer() creates an integer column, schema.string() creates a varchar, etc.
• validateField converts attribute names to snake_case using snakeCase() from @stacksjs/strings
• validateField skips attributes with default values unless isRequired is explicitly set
• Validation error messages are customizable per-rule in model definitions via the message object
• The schema export is the v instance from @stacksjs/ts-validation -- they are the same object
• Custom validators can be added with schema.custom<T>(fn, message) for types not covered by built-in validators
• customValidate uses schema.object().shape() while validateField uses schema.object(ruleObject) -- slightly different API