Katlego-Ram2/JUnit-testing

This project focuses on validating South African ID numbers using a Test-Driven Development (TDD) approach. Where: - `YYMMDD` – Date of Birth (e.g. `900101` = 1 Jan 1990) - `SSSS` – Gender sequence: - `0000–4999` = Female - `5000–9999` = Male - `C` – Citizenship: - `0` = SA Citizen - `1` = Permanent Resident - `A` – Usually 8 or 9 (not validated here) - `Z` – Luhn check digit --- ## ✅ Validation Checks ### Implemented in `ValidateSaId.java`: - 📏 **Length & numeric check**: Must be 13 digits. - 📅 **Valid date check**: `YYMMDD` must represent a real date. - 👤 **Gender code check**: Digits 7–10 must be in range `0000–9999`. - 🪪 **Citizenship digit**: Only `0` or `1` allowed. - 🔢 **Luhn checksum**: Final digit must satisfy the Luhn algorithm. --- ## 🧪 Unit Tests (`ValidateSaIdTest.java`) Includes comprehensive tests to verify: - ✅ Valid IDs (e.g., `2001014800086`, `2909035800085`) - ❌ Too short or too long inputs - ❌ Non-numeric characters - ❌ Invalid dates (e.g., 31st Feb, month 13) - ❌ Invalid citizenship digits (must be 0 or 1) - ❌ Invalid checksum values - ❌ Null inputs Sample test method: ```java @Test public void shouldReturnTrueForValidIDNumbers() { assertTrue(ValidateSaId.isIdNumberValid("2001014800086")); }