bchavez/Bogus · error · ArgumentException

Invalid country code

Error message

Invalid country code

What it means

Address.CountryCode(Iso3166Format) only handles Iso3166Format.Alpha2 and Iso3166Format.Alpha3 explicitly; any other value falls through to an ArgumentException. The enum only defines those two members, so with strongly-typed code this branch is effectively unreachable - it exists as a defensive guard against an enum value supplied via an invalid cast.

Source

Thrown at Source/Bogus/DataSets/Address.cs:160

   /// <summary>
   /// Get a random ISO 3166-1 country code.
   /// </summary>
   /// <param name="format">The format the country code should be in.</param>
   /// <returns>A random country code.</returns>
   public string CountryCode(Iso3166Format format = Iso3166Format.Alpha2)
   {
      if( format == Iso3166Format.Alpha2 )
      {
         return GetRandomArrayItem("country_code");
      }

      if( format == Iso3166Format.Alpha3 )
      {
         return GetRandomArrayItem("country_code_alpha_3");
      }

      throw new ArgumentException("Invalid country code", nameof(format));
   }

   /// <summary>
   /// Get a random state state.
   /// </summary>
   /// <returns>A random state.</returns>
   public string State()
   {
      return GetRandomArrayItem("state");
   }

   /// <summary>
   /// Get a state abbreviation.
   /// </summary>
   /// <returns>An abbreviation for a random state.</returns>
   public string StateAbbr()
   {
      return GetRandomArrayItem("state_abbr");

View on GitHub (pinned to 6ece18c5c2)

Solutions

1. Use the named enum values directly: Iso3166Format.Alpha2 or Iso3166Format.Alpha3.
2. If the value originates as an int, validate Enum.IsDefined(typeof(Iso3166Format), value) before calling CountryCode.
3. Default the parameter so callers rarely need to pass it: address.CountryCode() uses Alpha2.

Example fix

// before
var cc = address.CountryCode((Iso3166Format)incomingInt);

// after
if (!Enum.IsDefined(typeof(Iso3166Format), incomingInt))
    throw new ArgumentException("Unsupported country code format");
var cc = address.CountryCode((Iso3166Format)incomingInt);

Iso3166Format fmt = Iso3166Format.Alpha2;
if (!Enum.IsDefined(typeof(Iso3166Format), fmt))
    throw new ArgumentOutOfRangeException(nameof(fmt));
var cc = address.CountryCode(fmt);

static bool IsValid(Iso3166Format f) => f == Iso3166Format.Alpha2 || f == Iso3166Format.Alpha3;

When it happens

Trigger: Casting an arbitrary integer to Iso3166Format, e.g. address.CountryCode((Iso3166Format)99) or (Iso3166Format)5. This happens when the format comes from deserialized config/JSON as an int and is cast to the enum without bounds checking.

Common situations: Reading a numeric country-code-format value from configuration or an API payload and casting it directly to Iso3166Format. Values other than 2 (Alpha2) and 3 (Alpha3) trip the guard.

Related errors

• Gender not handled.
• The locale '{locale}' does not exist. To see all available l
• The country code must be an ISO3166 two-letter country code.
• The specified property '{property.Name}' does not have a set
• [{registrationNumberType}] is not a supported [{nameof(VatRe

AI-assisted analysis of bchavez/Bogus@6ece18c5c2 (2026-08-13). Data as JSON: /api/errors/199545d0f0a58610. Report an issue: GitHub.