@All Here is the code
@isTest public class Calculator_Tests { @isTest public static void additionPositiveTest() { integer a = 2; integer b = 3; integer c = Calculator.addition(a, b); System.assertEquals(5, c, 'expected result is 5'); } @isTest public static void substractionPositiveTest() { integer a = 6; integer b = 2; integer c = Calculator.subtraction(a, b); System.assertEquals(4, c, 'expected result is 4'); } @isTest public static void multiplyPositiveTest() { integer a = 2; integer b = 3; integer c = Calculator.multiply(a, b); System.assertEquals(6, c, 'expected result is 6'); } @isTest public static void dividePositiveTest() { integer a = 8; integer b = 2; decimal c = Calculator.divide(a, b); System.assertEquals(4, c, 'expected result is 4'); } @isTest public static void multiplyNegativeTest() { integer a = 0; integer b = 3; try { Calculator.multiply(a, b); } catch (Calculator.CalculatorException e) { System.assertEquals(e.getMessage(), 'It doesn\'t make sense to multiply by zero'); } } @isTest public static void divideByZeroTest(){ integer a = 5; integer b = 0; try { Calculator.divide(a, b); } catch (Calculator.CalculatorException e) { System.assertEquals(e.getMessage(), 'you still can\'t divide by zero'); } } @isTest public static void divideByNegativeTest() { Test.startTest(); integer a = 3; integer b = -1; Boolean exceptionNeg = false; try { Calculator.divide(b, a); } catch (Calculator.CalculatorException e) { if (e.getMessage().contains('Division returned a negative value.')) { exceptionNeg = true; } System.assertEquals(false, exceptionNeg); } Test.stopTest(); } }
Hi,
try the following:
Apex Class:
public class Calculator {
public class CalculatorException extends Exception{}
public static Integer addition(Integer a, Integer b){
return a + b;
}
public static Integer subtraction(Integer a, Integer b){
return a - b;
}
public static Integer multiply(Integer a, Integer b){
if(b==0 || a==0){
throw new CalculatorException('It doesn\'t make sense to multiply by zero');
}
return a * b;
}
public static Decimal divide(Integer numerator, Integer denominator){
if(denominator == 0){
throw new CalculatorException('you still can\'t divide by zero');
}
if(numerator < 0 || denominator < 0)
throw new CalculatorException('negative value(s) not allowed.');
Decimal returnValue = numerator / denominator;
return returnValue;
}
}
Test Class:
@isTest
public class Calculator_Tests {
@isTest
public static void addition() {
Calculator.addition(1, 0);
}
@isTest
public static void subtraction() {
Calculator.subtraction(1, 0);
}
@isTest
public static void divide_throws_exception_for_division_by_zero() {
Boolean caught = false;
try {
Calculator.divide(1, 0);
} catch (Calculator.CalculatorException e) {
System.assertEquals('you still can\'t divide by zero', e.getMessage(),
'caught the right exception');
caught = true;
}
System.assert(caught, 'threw expected exception');
}
@isTest
public static void divide_throws_exception_for_division_by_two() {
Boolean caught = true;
try {
Calculator.divide(1, 2);
} catch (Calculator.CalculatorException e) {
System.assertEquals('you still can\'t divide by zero', e.getMessage(),
'caught the right exception');
caught = true;
}
System.assert(caught, 'threw expected exception');
}
@isTest
public static void multiply_by_one() {
Boolean caught = false;
try {
Calculator.multiply(1, 0);
} catch (Calculator.CalculatorException e) {
System.assertEquals('It doesn\'t make sense to multiply by zero',
e.getMessage(), 'caught the right exception');
caught = true;
}
System.assert(caught, 'threw expected exception');
}
@isTest
public static void multiply_by_two() {
Boolean caught = true;
try {
Calculator.multiply(1, 2);
} catch (Calculator.CalculatorException e) {
System.assertEquals('It doesn\'t make sense to multiply by zero',
e.getMessage(), 'caught the right exception');
caught = true;
}
System.assert(caught, 'threw expected exception');
}
@isTest
public static void divide_throws_exception_for_negative_number() {
Boolean caught = true;
try {
Calculator.divide(-1, 2);
} catch (Calculator.CalculatorException e) {
System.assertEquals('negative value(s) not allowed.',e.getMessage());
caught = true;
}
System.assert(caught, 'threw expected exception');
}
}
ref: https://probablesolution.blogspot.com/2021/10/trailhead-challenge-error-100-coverage.html
