Required fields

This rule enforces that fields that are annotated as required do not use the optional syntax, as mandated by AIP-203.

Details

This rule looks for fields with a google.api.field_behavior annotation set to REQUIRED, and complains if the field also uses the proto3 optional syntax.

Examples

Incorrect code for this rule:

// Incorrect.
message Book {
  string name = 1;

  // Fields must not be optional and required.
  optional string title = 2 [(google.api.field_behavior) = REQUIRED];
}

Correct code for this rule:

// Incorrect.
message Book {
  string name = 1;

  string title = 2 [(google.api.field_behavior) = REQUIRED];
}

Disabling

If you need to violate this rule, use a leading comment above the field. Remember to also include an aip.dev/not-precedent comment explaining why.

message Book {
  string name = 1;

  // Required. The title of the book.
  // (-- api-linter: core::0203::required-and-optional=disabled
  //     aip.dev/not-precedent: We need to do this because reasons. --)
  optional string title = 2 [(google.api.field_behavior) = REQUIRED];
}

If you need to violate this rule for an entire file, place the comment at the top of the file.