Schema validation is a core feature of Orionjs that ensures data conforms to the structure and rules defined in your schemas. This is particularly important for ensuring data integrity in your application.

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Automatic Validation

When using a schema with MongoDB collections or GraphQL resolvers, validation happens automatically:
  • MongoDB: Documents are validated before being inserted or updated
  • GraphQL: Input data is validated before being processed by your resolvers
This automatic validation ensures that your data always adheres to your schema rules.

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Manual Validation

You can also manually validate any object against a schema using the validate function: 
import {validate} from '@orion-js/schema'
import {UserSchema} from './schemas/UserSchema'

try {
  await validate(UserSchema, {
    name: 'John Doe',
    email: 'john@example.com'
  })
  // Validation passed
} catch (error) {
  // error is a ValidationError
  console.error(error.message)
  console.error(error.details) // Contains detailed information about validation failures
}
The validate function will:
  1. Check that all required fields are present
  2. Verify types match the schema definition
  3. Apply any validation rules defined in the schema
  4. Throw a ValidationError if validation fails

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ValidationError

When validation fails, a ValidationError is thrown with: 
{
  message: 'Validation Error', // Human-readable error message
  details: [
    {
      message: 'is required', // Human-readable field error message
      path: 'email' // Path to the field that failed validation
    }
  ]
}
For nested fields, the path will include the full path to the field: 
{
  details: [
    {
      message: 'must be at least 5 characters',
      path: 'address.street'
    }
  ]
}

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Custom Validation

You can create custom validation rules using the validate option in property definitions: 
import {schemaWithName, InferSchemaType} from '@orion-js/schema'

export const ProductSchema = schemaWithName('ProductSchema', {
  price: {
    type: Number,
    validate: (value) => {
      if (value < 0) {
        return 'price-must-be-positive'
      }
      if (value > 1000000) {
        return 'price-too-high'
      }
    }
  },
  
  slug: {
    type: String,
    validate: async (value) => {
      // You can also perform async validation
      const exists = await checkIfSlugExists(value)
      if (exists) {
        return 'slug-already-exists'
      }
    }
  }
})

export type ProductType = InferSchemaType<typeof ProductSchema>
The validate function:
  • Receives the field value as its first parameter
  • Should return an error message string if validation fails
  • Should return nothing (undefined) if validation passes
  • Can be async (returns a Promise)

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Advanced Validation

For more complex validation that depends on multiple fields, you can use the options object: 
billingInfo: {
  type: String,
  optional: true,
  validate: (value, {doc}) => {
    if (doc.type === 'subscription' && !value) {
      return 'billing-info-required-for-subscriptions'
    }
  }
}

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Cleaning Data

Before validation, Orionjs “cleans” the data by:
  1. Removing fields not defined in the schema
  2. Applying any clean functions defined on fields
  3. Setting default values for missing fields
You can manually clean data using the clean function: 
import {clean} from '@orion-js/schema'
import {UserSchema} from './schemas/UserSchema'

const cleanedData = await clean(UserSchema, {
  name: 'John Doe ',  // Note the trailing space
  email: 'JOHN@EXAMPLE.COM',
  extraField: 'This will be removed'
})

// Result:
// {
//   name: 'John Doe',  // If a clean function trims the string
//   email: 'john@example.com',  // If a clean function lowercases the email
// }

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Validation in GraphQL Resolvers

When using schemas with GraphQL resolvers, validation happens automatically for parameters: 
import {createMutation, Resolvers} from '@orion-js/graphql'
import {schemaWithName, InferSchemaType} from '@orion-js/schema'

export const CreateUserParams = schemaWithName('CreateUserParams', {
  name: {type: String, min: 2},
  email: {type: String}
})

export type CreateUserParamsType = InferSchemaType<typeof CreateUserParams>

@Resolvers()
class UserResolvers {
  @Mutation()
  createUser = createMutation({
    params: CreateUserParams,
    returns: Boolean,
    resolve: async (params: CreateUserParamsType) => {
      // Params are already validated
      // If validation failed, GraphQL would return an error
      // ...implementation
      return true
    }
  })
}
This ensures that your API is always receiving valid data before it reaches your business logic.

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Validation in Schema Definition

When defining a property in a schema, you can specify validation constraints: 
import {schemaWithName, InferSchemaType} from '@orion-js/schema'

export const ProductSchema = schemaWithName('ProductSchema', {
  name: {
    type: String,
    min: 3,
    max: 100,
    validate: value => {
      if (value.includes('forbidden')) {
        return 'name-contains-forbidden-word'
      }
    }
  },
  
  price: {
    type: Number,
    min: 0
  },
  
  description: {
    type: String,
    optional: true
  }
})

export type ProductType = InferSchemaType<typeof ProductSchema>
The validation will run automatically when:
  1. A document is validated against the schema (e.g., in MongoDB operations)
  2. A GraphQL input is processed
  3. You manually call clean or validate on your schema