tests added

test/support/iban_factory.exs

@@ -0,0 +1,210 @@
+defmodule IbanEx.IbanFactory do
+  @moduledoc """
+  Factory for creating IBAN test fixtures with various attributes.
+  Supports creating valid and invalid IBANs for comprehensive testing.
+  """
+
+  alias IbanEx.{Iban, Country}
+
+  @doc """
+  Build an IBAN struct with custom attributes.
+
+  ## Options
+  - `:country_code` - Two-letter country code (default: "DE")
+  - `:check_digits` - Two-digit check code (default: auto-calculated)
+  - `:bank_code` - Bank identifier code
+  - `:branch_code` - Branch identifier code
+  - `:account_number` - Account number
+  - `:national_check` - National check digit(s)
+  - `:iban` - Full IBAN string (overrides other options)
+
+  ## Examples
+
+      iex> IbanEx.IbanFactory.build(country_code: "DE")
+      %IbanEx.Iban{country_code: "DE", ...}
+
+      iex> IbanEx.IbanFactory.build(iban: "DE89370400440532013000")
+      %IbanEx.Iban{country_code: "DE", check_code: "89", ...}
+  """
+  def build(attrs \\ []) do
+    if iban_string = Keyword.get(attrs, :iban) do
+      build_from_string(iban_string)
+    else
+      build_from_attrs(attrs)
+    end
+  end
+
+  @doc """
+  Build an IBAN with an invalid checksum.
+
+  ## Examples
+
+      iex> iban = IbanEx.IbanFactory.build_with_invalid_checksum(country_code: "DE")
+      iex> IbanEx.Validator.valid?(iban.iban)
+      false
+  """
+  def build_with_invalid_checksum(attrs \\ []) do
+    iban = build(attrs)
+
+    # Flip the last digit of check code to make it invalid
+    current_check = iban.check_code
+    invalid_check = flip_last_digit(current_check)
+
+    invalid_iban =
+      String.replace(iban.iban, ~r/^[A-Z]{2}\d{2}/, "#{iban.country_code}#{invalid_check}")
+
+    %{iban | iban: invalid_iban, check_code: invalid_check}
+  end
+
+  @doc """
+  Build an IBAN with invalid length (too short).
+  """
+  def build_with_invalid_length_short(attrs \\ []) do
+    iban = build(attrs)
+    invalid_iban = String.slice(iban.iban, 0..-2//1)
+
+    %{iban | iban: invalid_iban}
+  end
+
+  @doc """
+  Build an IBAN with invalid length (too long).
+  """
+  def build_with_invalid_length_long(attrs \\ []) do
+    iban = build(attrs)
+    invalid_iban = iban.iban <> "0"
+
+    %{iban | iban: invalid_iban}
+  end
+
+  @doc """
+  Build an IBAN with invalid characters in BBAN.
+  """
+  def build_with_invalid_characters(attrs \\ []) do
+    iban = build(attrs)
+
+    # Replace a digit in the BBAN with an invalid character
+    bban_start = 4
+    iban_chars = String.graphemes(iban.iban)
+
+    invalid_chars =
+      List.replace_at(iban_chars, bban_start + 2, "Ї")
+      |> Enum.join()
+
+    %{iban | iban: invalid_chars}
+  end
+
+  @doc """
+  Build an IBAN with unsupported country code.
+  """
+  def build_with_unsupported_country do
+    # Return the IBAN string directly since XX is not supported
+    "XX89370400440532013000"
+  end
+
+  # Private functions
+
+  defp build_from_string(iban_string) do
+    case IbanEx.parse(iban_string) do
+      {:ok, iban} -> iban
+      {:error, _} -> raise "Invalid IBAN string: #{iban_string}"
+    end
+  end
+
+  defp build_from_attrs(attrs) do
+    country_code = Keyword.get(attrs, :country_code, "DE")
+
+    # Get a valid example IBAN for this country
+    example_iban = get_example_iban(country_code)
+
+    # Parse it to get the structure
+    {:ok, base_iban} = IbanEx.parse(example_iban)
+
+    # Override with provided attributes
+    %{
+      base_iban
+      | bank_code: Keyword.get(attrs, :bank_code, base_iban.bank_code),
+        branch_code: Keyword.get(attrs, :branch_code, base_iban.branch_code),
+        account_number: Keyword.get(attrs, :account_number, base_iban.account_number),
+        national_check: Keyword.get(attrs, :national_check, base_iban.national_check)
+    }
+    |> rebuild_iban()
+  end
+
+  defp get_example_iban(country_code) do
+    # Use the test fixtures to get a valid example
+    fixtures_path =
+      Path.join([
+        __DIR__,
+        "..",
+        "..",
+        "docs",
+        "international_wide_ibans",
+        "iban_test_fixtures.json"
+      ])
+
+    fixtures =
+      fixtures_path
+      |> File.read!()
+      |> JSON.decode!()
+
+    fixtures["valid_ibans"][country_code]["electronic"]
+  end
+
+  defp rebuild_iban(iban) do
+    # Reconstruct the BBAN from components
+    bban_parts =
+      [
+        iban.bank_code,
+        iban.branch_code,
+        iban.account_number,
+        iban.national_check
+      ]
+      |> Enum.reject(&is_nil/1)
+      |> Enum.join()
+
+    # Calculate the check digits
+    check_digits = calculate_check_digits(iban.country_code, bban_parts)
+
+    iban_string = "#{iban.country_code}#{check_digits}#{bban_parts}"
+
+    %{iban | iban: iban_string, check_code: check_digits}
+  end
+
+  defp calculate_check_digits(country_code, bban) do
+    # Move country code and "00" to end, then mod 97
+    rearranged = bban <> country_code <> "00"
+
+    # Replace letters with numbers (A=10, B=11, ..., Z=35)
+    numeric =
+      rearranged
+      |> String.graphemes()
+      |> Enum.map(fn char ->
+        if char =~ ~r/[A-Z]/ do
+          [char_code] = String.to_charlist(char)
+          Integer.to_string(char_code - 55)
+        else
+          char
+        end
+      end)
+      |> Enum.join()
+
+    # Calculate mod 97
+    remainder =
+      numeric
+      |> String.to_integer()
+      |> rem(97)
+
+    # Check digit is 98 - remainder
+    check = 98 - remainder
+
+    check
+    |> Integer.to_string()
+    |> String.pad_leading(2, "0")
+  end
+
+  defp flip_last_digit(check_code) do
+    last_digit = String.last(check_code)
+    flipped = if last_digit == "0", do: "1", else: "0"
+    String.slice(check_code, 0..-2//1) <> flipped
+  end
+end