Add unit tests for ParseInteger (#4228)

This commit is contained in:
Albina Gimaletdinova
2023-07-02 11:31:55 +03:00
committed by GitHub
parent 4b45ac7e71
commit 2456d86432
3 changed files with 48 additions and 11 deletions

View File

@ -656,6 +656,7 @@
* [MobiusFunctionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/MobiusFunctionTest.java)
* [NthUglyNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/NthUglyNumberTest.java)
* [PalindromeNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/PalindromeNumberTest.java)
* [ParseIntegerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/ParseIntegerTest.java)
* [PascalTriangleTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/PascalTriangleTest.java)
* [PerfectCubeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/PerfectCubeTest.java)
* [PerfectNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/maths/PerfectNumberTest.java)

View File

@ -1,32 +1,24 @@
package com.thealgorithms.maths;
public class ParseInteger {
public static void main(String[] args) {
assert parseInt("123") == Integer.parseInt("123");
assert parseInt("-123") == Integer.parseInt("-123");
assert parseInt("0123") == Integer.parseInt("0123");
assert parseInt("+123") == Integer.parseInt("+123");
}
/**
* Parse a string to integer
*
* @param s the string
* @return the integer value represented by the argument in decimal.
* @throws NumberFormatException if the {@code string} does not contain a
* parsable integer.
* parsable integer.
*/
public static int parseInt(String s) {
if (s == null || s.length() == 0) {
throw new NumberFormatException("null");
throw new NumberFormatException("Input parameter must not be null!");
}
boolean isNegative = s.charAt(0) == '-';
boolean isPositive = s.charAt(0) == '+';
int number = 0;
for (int i = isNegative ? 1 : isPositive ? 1 : 0, length = s.length(); i < length; ++i) {
if (!Character.isDigit(s.charAt(i))) {
throw new NumberFormatException("s=" + s);
throw new NumberFormatException("Input parameter of incorrect format: " + s);
}
number = number * 10 + s.charAt(i) - '0';
}

View File

@ -0,0 +1,44 @@
package com.thealgorithms.maths;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
/**
* @author Albina Gimaletdinova on 01/07/2023
*/
public class ParseIntegerTest {
private static final String NULL_PARAMETER_MESSAGE = "Input parameter must not be null!";
private static final String INCORRECT_FORMAT_MESSAGE = "Input parameter of incorrect format";
@Test
public void testNullInput() {
IllegalArgumentException exception = Assertions.assertThrows(IllegalArgumentException.class, () -> ParseInteger.parseInt(null));
Assertions.assertEquals(exception.getMessage(), NULL_PARAMETER_MESSAGE);
}
@Test
public void testInputOfIncorrectFormat() {
IllegalArgumentException exception = Assertions.assertThrows(NumberFormatException.class, () -> ParseInteger.parseInt("+0a123"));
Assertions.assertTrue(exception.getMessage().contains(INCORRECT_FORMAT_MESSAGE));
exception = Assertions.assertThrows(NumberFormatException.class, () -> ParseInteger.parseInt("b"));
Assertions.assertTrue(exception.getMessage().contains(INCORRECT_FORMAT_MESSAGE));
}
@Test
public void testPositiveValueIsSuccessfullyConverted() {
Assertions.assertEquals(ParseInteger.parseInt("0"), Integer.parseInt("0"));
Assertions.assertEquals(ParseInteger.parseInt("123"), Integer.parseInt("123"));
Assertions.assertEquals(ParseInteger.parseInt("0123"), Integer.parseInt("0123"));
Assertions.assertEquals(ParseInteger.parseInt("+0123"), Integer.parseInt("+0123"));
Assertions.assertEquals(ParseInteger.parseInt("+123"), Integer.parseInt("+123"));
}
@Test
public void testNegativeValueIsSuccessfullyConverted() {
Assertions.assertEquals(ParseInteger.parseInt("-1"), Integer.parseInt("-1"));
Assertions.assertEquals(ParseInteger.parseInt("-123"), Integer.parseInt("-123"));
Assertions.assertEquals(ParseInteger.parseInt("-0123"), Integer.parseInt("-0123"));
Assertions.assertEquals(ParseInteger.parseInt("-00123"), Integer.parseInt("-00123"));
}
}