Violations messages

Violations Message

Violations is a collection of Violation messages. This message type is returned by protovalidate when a proto message fails to meet the requirements set by the Constraint validation rules. Each individual violation is represented by a Violation message.

violations

violations is a repeated field that contains all the Violation messages corresponding to the violations detected.

Violation Message

Violation represents a single instance where a validation rule, expressed as a Constraint, was not met. It provides information about the field that caused the violation, the specific constraint that wasn't fulfilled, and a human-readable error message.

{
  "fieldPath": "bar",
  "constraintId": "foo.bar",
  "message": "bar must be greater than 0"
}

field

field is a machine-readable path to the field that failed validation. This could be a nested field, in which case the path will include all the parent fields leading to the actual field that caused the violation.

For example, consider the following message:

message Message {
  bool a = 1 [(buf.validate.field).required = true];
}

It could produce the following violation:

violation {
  field { element { field_number: 1, field_name: "a", field_type: 8 } }
  ...
}

rule

rule is a machine-readable path that points to the specific constraint rule that failed validation. This will be a nested field starting from the FieldConstraints of the field that failed validation. For custom constraints, this will provide the path of the constraint, e.g. cel[0].

For example, consider the following message:

message Message {
  bool a = 1 [(buf.validate.field).required = true];
  bool b = 2 [(buf.validate.field).cel = {
    id: "custom_constraint",
    expression: "!this ? 'b must be true': ''"
  }]
}

It could produce the following violations:

violation {
  rule { element { field_number: 25, field_name: "required", field_type: 8 } }
  ...
}
violation {
  rule { element { field_number: 23, field_name: "cel", field_type: 11, index: 0 } }
  ...
}

constraint_id

constraint_id is the unique identifier of the Constraint that was not fulfilled. This is the same id that was specified in the Constraint message, allowing easy tracing of which rule was violated.

message

message is a human-readable error message that describes the nature of the violation. This can be the default error message from the violated Constraint, or it can be a custom message that gives more context about the violation.

for_key

for_key indicates whether the violation was caused by a map key, rather than a value.