Equivalence Partitioning

// Example: Age validation (18-65)
function testAgeEquivalencePartitions() {
    // Valid partition: 18-65
    // Invalid partitions: <18, >65, non-numeric
    
    // Test one value from valid partition
    expect(validateAge(25)).toBe(true); // Representative of 18-65
    
    // Test one value from each invalid partition
    expect(validateAge(17)).toBe(false); // Representative of <18
    expect(validateAge(66)).toBe(false); // Representative of >65
    expect(validateAge("abc")).toBe(false); // Representative of non-numeric
}

// Example: Grade calculation
function testGradeEquivalencePartitions() {
    // A: 90-100
    // B: 80-89
    // C: 70-79
    // D: 60-69
    // F: 0-59
    // Invalid: <0, >100, non-numeric
    
    // Test one value from each valid partition
    expect(getGrade(95)).toBe('A'); // Representative of 90-100
    expect(getGrade(85)).toBe('B'); // Representative of 80-89
    expect(getGrade(75)).toBe('C'); // Representative of 70-79
    expect(getGrade(65)).toBe('D'); // Representative of 60-69
    expect(getGrade(55)).toBe('F'); // Representative of 0-59
    
    // Test invalid partitions
    expect(getGrade(-5)).toBe('Invalid'); // Representative of <0
    expect(getGrade(105)).toBe('Invalid'); // Representative of >100
    expect(getGrade("abc")).toBe('Invalid'); // Representative of non-numeric
}

// Example: Email validation
function testEmailEquivalencePartitions() {
    // Valid: proper email format
    // Invalid: missing @, missing domain, missing username, etc.
    
    // Test valid partition
    expect(validateEmail("user@example.com")).toBe(true);
    
    // Test invalid partitions
    expect(validateEmail("userexample.com")).toBe(false); // Missing @
    expect(validateEmail("@example.com")).toBe(false); // Missing username
    expect(validateEmail("user@")).toBe(false); // Missing domain
    expect(validateEmail("user@example")).toBe(false); // Missing TLD
    expect(validateEmail("")).toBe(false); // Empty string
}