Standardized code strings

This rule attempts to enforce that standard codes for concepts like language, currency, etc. are strings, as mandated in AIP-143.

Details

This rule looks at any field with a name matching a standardized code, and complains if it has a type other than string.

It currently matches the following field names:

• currency_code
• country_code
• language_code
• mime_type
• time_zone

Examples

Incorrect code for this rule:

// Incorrect.
// This enum should not exist.
enum LanguageCode {
  LANGUAGE_CODE_UNSPECIFIED = 0;
  EN_US = 1;
  EN_GB = 2;
}

message Book {
  string name = 1;
  LanguageCode language_code = 2;  // Should be `string`.
}

Correct code for this rule:

// Correct.
message Book {
  string name = 1;
  string language_code = 2;
}

Disabling

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

// (-- api-linter: core::0143::string-type=disabled
//     aip.dev/not-precedent: We need to do this because reasons. --)
enum LanguageCode {
  LANGUAGE_CODE_UNSPECIFIED = 0;
  EN_US = 1;
  EN_GB = 2;
}

message Book {
  string name = 1;
  LanguageCode language_code = 2;
}

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