Validation

Neogma validates node properties before they are persisted to Neo4j using TypeBox schemas.

TypeBox validation

TypeBox provides type-safe validation schemas. Import Type directly from neogma:

import { Type } from 'neogma';

Basic types

@Property(Type.String())         // must be a string
@Property(Type.Number())         // must be a number
@Property(Type.Boolean())        // must be a boolean
@Property(Type.Array(Type.String())) // must be an array of strings

Constraints

// String constraints
@Property(Type.String({ minLength: 3, maxLength: 100 }))
name!: string;

// Number constraints
@Property(Type.Number({ minimum: 0, maximum: 150 }))
age!: number;

// Pattern matching
@Property(Type.String({ pattern: '^[a-zA-Z0-9]+$' }))
username!: string;

Optional properties

Use Type.Optional() for properties that may be undefined:

@Property(Type.Optional(Type.String()))
nickname?: string;

@Property(Type.Optional(Type.Number({ minimum: 0 })))
score?: number;

Enum values

@Property(Type.Union([
  Type.Literal('active'),
  Type.Literal('inactive'),
  Type.Literal('pending'),
]))
status!: string;

Relationship property validation

TypeBox schemas can also validate relationship properties:

@Relationship({
  name: 'RATED',
  direction: 'out',
  model: () => ProductNode,
  properties: [
    {
      property: 'rating',
      alias: 'Rating',
      schema: Type.Number({ minimum: 1, maximum: 5 }),
    },
  ],
})
RatedProducts!: Related<typeof ProductNode, { Rating: number }, { rating: number }>;

Validation errors

When validation fails, neogma throws a NeogmaInstanceValidationError:

import { NeogmaInstanceValidationError } from 'neogma';

try {
  await Users.createOne({ id: '1', name: '' }); // fails: minLength: 1
} catch (error) {
  if (error instanceof NeogmaInstanceValidationError) {
    console.log(error.message);
    console.log(error.errors); // detailed validation errors
  }
}

Validation

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