Itin parser and validator added

test/ukraine_taxid_ex/itin/check_sum_test.exs

@@ -0,0 +1,95 @@
+defmodule UkraineTaxidEx.Itin.CheckSumTest do
+  use ExUnit.Case, async: true
+  alias UkraineTaxidEx.Itin.CheckSum
+
+  describe "weights/0" do
+    test "returns the correct list of weights" do
+      expected_weights = [-1, 5, 7, 9, 4, 6, 10, 5, 7]
+      assert CheckSum.weights() == expected_weights
+    end
+
+    test "returns a list of 9 weights" do
+      assert length(CheckSum.weights()) == 9
+    end
+  end
+
+  describe "check_sum/2" do
+    test "calculates correct checksum for valid ITIN (3334513284)" do
+      # Test case with known ITIN and its checksum
+      digits = [3, 3, 3, 4, 5, 1, 3, 2, 8, 4]
+      assert CheckSum.check_sum(digits) == 4
+    end
+
+    test "calculates correct checksum for valid ITIN (2038817850)" do
+      # Test case with known ITIN and its checksum
+      digits = [2, 0, 3, 8, 8, 1, 7, 8, 5, 0]
+      assert CheckSum.check_sum(digits) == 0
+    end
+
+    test "calculates correct checksum for valid ITIN (3486110380)" do
+      # Test case with known ITIN and its checksum
+      digits = [3, 4, 8, 6, 1, 1, 0, 3, 8, 0]
+      assert CheckSum.check_sum(digits) == 0
+    end
+
+    test "calculates correct checksum for valid ITIN (3402109517)" do
+      # Test case with known ITIN and its checksum
+      digits = [3, 4, 0, 2, 1, 0, 9, 5, 1, 7]
+      assert CheckSum.check_sum(digits) == 7
+    end
+
+    test "calculates correct checksum for valid ITIN (2598917292)" do
+      # Test case with known ITIN and its checksum
+      digits = [2, 5, 9, 8, 9, 1, 7, 2, 9, 2]
+      assert CheckSum.check_sum(digits) == 2
+    end
+
+    test "calculates correct checksum for valid ITIN (3505804094)" do
+      # Test case with known ITIN and its checksum
+      digits = [3, 5, 0, 5, 8, 0, 4, 0, 9, 4]
+      assert CheckSum.check_sum(digits) == 4
+    end
+
+    test "calculates correct checksum for valid ITIN (2971306745)" do
+      # Test case with known ITIN and its checksum
+      digits = [2, 9, 7, 1, 3, 0, 6, 7, 4, 5]
+      assert CheckSum.check_sum(digits) == 5
+    end
+
+    test "calculates correct checksum for ITIN with invalid check digit (2598917291)" do
+      # Test case with known ITIN and its checksum
+      digits = [2, 5, 9, 8, 9, 1, 7, 2, 9, 1]
+      assert CheckSum.check_sum(digits) == 2
+    end
+
+    test "calculates correct checksum for ITIN with invalid check digit (3505804099)" do
+      # Test case with known ITIN and its checksum
+      digits = [3, 5, 0, 5, 8, 0, 4, 0, 9, 9]
+      assert CheckSum.check_sum(digits) == 4
+    end
+
+    test "calculates correct checksum for ITIN with invalid check digit (2971306747)" do
+      # Test case with known ITIN and its checksum
+      digits = [2, 9, 7, 1, 3, 0, 6, 7, 4, 7]
+      assert CheckSum.check_sum(digits) == 5
+    end
+
+    test "calculates checksum with custom weights" do
+      digits = [1, 2, 3]
+      weights = [1, 2, 3]
+      assert CheckSum.check_sum(digits, weights) == 5
+    end
+
+    test "handles zero digits" do
+      digits = [0, 0, 0, 0, 0, 0, 0, 0, 0]
+      assert CheckSum.check_sum(digits) == 0
+    end
+
+    test "handles single digit input" do
+      digits = [5]
+      weights = [2]
+      # (5*2) = 10 % 11 % 10 = 0
+      assert CheckSum.check_sum(digits, weights) == 0
+    end
+  end
+end

test/ukraine_taxid_ex/itin/parser_test.exs

@@ -0,0 +1,87 @@
+defmodule UkraineTaxidEx.Itin.ParserTest do
+  use ExUnit.Case, async: true
+  alias UkraineTaxidEx.Itin
+  alias UkraineTaxidEx.Itin.Parser
+
+  describe "parse/1" do
+    test "successfully parses valid ITIN" do
+      assert {:ok, %Itin{} = itin} = Parser.parse("2847211760")
+      assert itin.code == "2847211760"
+      assert itin.birth_date == ~D[1977-12-14]
+      assert itin.number == 1176
+      assert itin.gender == 0
+      assert itin.check_sum == 0
+      assert itin.check_digit == 0
+
+      assert {:ok, %Itin{} = itin} = Parser.parse("3176422893")
+      assert itin.code == "3176422893"
+      assert itin.birth_date == ~D[1986-12-19]
+      assert itin.number == 2289
+      assert itin.gender == 1
+      assert itin.check_sum == 3
+      assert itin.check_digit == 3
+    end
+
+    test "returns error for string shorter than required length" do
+      assert {:error, :length_too_short} = Parser.parse("123456")
+    end
+
+    test "returns error for string longer than required length" do
+      assert {:error, :length_too_long} = Parser.parse("12345678901")
+    end
+
+    test "returns error for invalid checksum" do
+      assert {:error, :invalid_checksum} = Parser.parse("1234567890")
+    end
+  end
+
+  describe "birth_date/1" do
+    test "calculates correct birth date from digits" do
+      digits = [3, 7, 5, 8, 0, 0, 5, 3, 6, 4]
+      assert Parser.birth_date(digits) == ~D[2002-11-21]
+
+      digits = [3, 0, 4, 3, 2, 1, 6, 8, 2, 4]
+      assert Parser.birth_date(digits) == ~D[1983-04-27]
+
+      digits = [2, 8, 8, 1, 2, 2, 0, 4, 5, 2]
+      assert Parser.birth_date(digits) == ~D[1978-11-19]
+    end
+  end
+
+  describe "number/1" do
+    test "extracts correct number from digits" do
+      digits = [2, 8, 8, 1, 2, 2, 0, 4, 5, 2]
+      assert Parser.number(digits) == 2045
+
+      digits = [3, 5, 8, 9, 4, 1, 2, 3, 7, 1]
+      assert Parser.number(digits) == 1237
+
+      digits = [3, 2, 1, 5, 6, 0, 5, 0, 5, 3]
+      assert Parser.number(digits) == 505
+    end
+  end
+
+  describe "gender/1" do
+    test "determines correct gender from digits" do
+      # Even number in the second-to-last position (gender 1)
+      digits = [2, 5, 8, 5, 1, 1, 9, 1, 1, 5]
+      assert Parser.gender(digits) == 1
+
+      digits = [2, 6, 0, 3, 8, 2, 1, 5, 3, 1]
+      assert Parser.gender(digits) == 1
+
+      # Odd number in the second-to-last position (gender 0)
+      digits = [2, 2, 0, 7, 3, 1, 5, 4, 2, 8]
+      assert Parser.gender(digits) == 0
+
+      digits = [3, 1, 2, 6, 7, 0, 7, 0, 2, 6]
+      assert Parser.gender(digits) == 0
+    end
+  end
+
+  describe "base_date/0" do
+    test "returns the correct base date" do
+      assert Parser.base_date() == ~D[1899-12-31]
+    end
+  end
+end