symfony/tests/Symfony/Tests/Component/Validator/Mapping/Loader/constraint-mapping.yml

namespaces:
  custom: Symfony\Tests\Component\Validator\Fixtures\

Symfony\Tests\Component\Validator\Fixtures\Entity:
  constraints:
    # Custom constraint
    - Symfony\Tests\Component\Validator\Fixtures\ConstraintA: ~
    # Custom constraint with namespaces prefix
    - "custom:ConstraintB": ~

  properties:
    firstName:
      # Constraint without value
      - NotNull: ~
      # Constraint with single value
      - Min: 3
      # Constraint with multiple values
      - Choice: [A, B]
      # Constraint with child constraints
      - All:
          - NotNull: ~
          - Min: 3
      # Option with child constraints
      - All:
          constraints:
            - NotNull: ~
            - Min: 3
      # Value with child constraints
      - Collection:
          fields:
            foo:
              - NotNull: ~
              - Min: 3
            bar:
              - Min: 5
      # Constraint with options
      - Choice: { choices: [A, B], message: Must be one of %choices% }

  getters:
    lastName:
      - NotNull: ~