Tag Revision requests: Tag field behavior

This rule enforces that all Tag Revision requests have google.api.field_behavior set to REQUIRED on their string tag field, as mandated in AIP-162.

Details

This rule looks at any message matching Tag*RevisionRequest and complains if the tag field does not have a google.api.field_behavior annotation with a value of REQUIRED.

Examples

Incorrect code for this rule:

// Incorrect.
message TagBookRevisionRequest {
  string name = 1 [
    (google.api.field_behavior) = REQUIRED,
    (google.api.resource_reference).type = "library.googleapis.com/Book"
  ];

  // The `google.api.field_behavior` annotation should be included.
  string tag = 2;
}

Correct code for this rule:

// Correct.
message TagBookRevisionRequest {
  string name = 1 [
    (google.api.field_behavior) = REQUIRED,
    (google.api.resource_reference).type = "library.googleapis.com/Book"
  ];

  string tag = 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 TagBookRevisionRequest {
  string name = 1 [
    (google.api.field_behavior) = REQUIRED,
    (google.api.resource_reference).type = "library.googleapis.com/Book"
  ];

  // (-- api-linter: core::0162::tag-revision-request-tag-behavior=disabled
  //     aip.dev/not-precedent: We need to do this because reasons. --)
  string tag = 2;
}

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