DDALineTest.java

package com.thealgorithms.geometry;

import java.awt.Point;
import java.util.List;
import java.util.stream.Stream;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

/**
 * The {@code DDALineTest} class contains unit tests for the
 * {@code DDALine} class, specifically testing the {@code findLine} method.
 */
class DDALineTest {

    static Stream<Arguments> linePointsProvider() {
        return Stream.of(Arguments.of(0, 0, 5, 5, List.of(new Point(0, 0), new Point(1, 1), new Point(2, 2), new Point(3, 3), new Point(4, 4), new Point(5, 5))), Arguments.of(0, 0, 5, 0, List.of(new Point(0, 0), new Point(1, 0), new Point(2, 0), new Point(3, 0), new Point(4, 0), new Point(5, 0))),
            Arguments.of(0, 0, 0, 5, List.of(new Point(0, 0), new Point(0, 1), new Point(0, 2), new Point(0, 3), new Point(0, 4), new Point(0, 5))), Arguments.of(-2, -2, -5, -5, List.of(new Point(-2, -2), new Point(-3, -3), new Point(-4, -4), new Point(-5, -5))),
            Arguments.of(1, 1, 1, 1, List.of(new Point(1, 1))), Arguments.of(0, 0, 1, 5, List.of(new Point(0, 0), new Point(0, 1), new Point(0, 2), new Point(1, 3), new Point(1, 4), new Point(1, 5))));
    }

    @ParameterizedTest
    @MethodSource("linePointsProvider")
    void testFindLine(int x0, int y0, int x1, int y1, List<Point> expected) {
        List<Point> actual = DDALine.findLine(x0, y0, x1, y1);
        Assertions.assertEquals(expected, actual, "The DDA algorithm should generate the expected ordered points.");
    }
}