diff --git a/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java b/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java index 882fe644ccd5..682240acd752 100644 --- a/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java +++ b/src/test/java/com/thealgorithms/stacks/PostfixEvaluatorTest.java @@ -4,24 +4,41 @@ import static org.junit.jupiter.api.Assertions.assertThrows; import java.util.EmptyStackException; +import org.junit.jupiter.api.DisplayName; import org.junit.jupiter.api.Test; +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.CsvSource; public class PostfixEvaluatorTest { - @Test - public void testValidExpressions() { - assertEquals(22, PostfixEvaluator.evaluatePostfix("5 6 + 2 *")); - assertEquals(27, PostfixEvaluator.evaluatePostfix("7 2 + 3 *")); - assertEquals(3, PostfixEvaluator.evaluatePostfix("10 5 / 1 +")); + @ParameterizedTest(name = "Expression: \"{0}\" → Result: {1}") + @CsvSource({"'5 6 + 2 *', 22", "'7 2 + 3 *', 27", "'10 5 / 1 +', 3", "'8', 8", "'3 4 +', 7"}) + @DisplayName("Valid postfix expressions") + void testValidExpressions(String expression, int expected) { + assertEquals(expected, PostfixEvaluator.evaluatePostfix(expression)); } @Test - public void testInvalidExpression() { + @DisplayName("Should throw EmptyStackException for incomplete expression") + void testInvalidExpression() { assertThrows(EmptyStackException.class, () -> PostfixEvaluator.evaluatePostfix("5 +")); } @Test - public void testMoreThanOneStackSizeAfterEvaluation() { + @DisplayName("Should throw IllegalArgumentException for extra operands") + void testExtraOperands() { assertThrows(IllegalArgumentException.class, () -> PostfixEvaluator.evaluatePostfix("5 6 + 2 * 3")); } + + @Test + @DisplayName("Should throw ArithmeticException for division by zero") + void testDivisionByZero() { + assertThrows(ArithmeticException.class, () -> PostfixEvaluator.evaluatePostfix("1 0 /")); + } + + @Test + @DisplayName("Should throw IllegalArgumentException for invalid characters") + void testInvalidToken() { + assertThrows(IllegalArgumentException.class, () -> PostfixEvaluator.evaluatePostfix("1 a +")); + } }