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

Symfony\Tests\Component\Validator\Fixtures\Entity:
  constraints:
    # Constraint without value
    - NotNull: ~
    # Custom constraint
    - Symfony\Tests\Component\Validator\Fixtures\ConstraintA: ~
    # 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
      
  properties:
    firstName:
      # Constraint with options
      - Choice: { choices: [A, B], message: Must be one of %choices% }
        
  getters:
    lastName:
      - NotNull: ~