refactor: ColorContrastRatio (#5457)

src/test/java/com/thealgorithms/misc/ColorContrastRatioTest.java

@@ -0,0 +1,33 @@
+package com.thealgorithms.misc;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.awt.Color;
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+class ColorContrastRatioTest {
+    private final ColorContrastRatio colorContrastRationCalculator = new ColorContrastRatio();
+
+    static Stream<Arguments> relativeLuminanceProvider() {
+        return Stream.of(Arguments.of(Color.BLACK, 0.0), Arguments.of(Color.WHITE, 1.0), Arguments.of(new Color(23, 103, 154), 0.12215748057375966), Arguments.of(new Color(226, 229, 248), 0.7898468477881603));
+    }
+
+    static Stream<Arguments> contrastRatioProvider() {
+        return Stream.of(Arguments.of(Color.BLACK, Color.WHITE, 21.0), Arguments.of(new Color(23, 103, 154), new Color(226, 229, 248), 4.878363954846178));
+    }
+
+    @ParameterizedTest
+    @MethodSource("relativeLuminanceProvider")
+    void testGetRelativeLuminance(Color color, double expectedLuminance) {
+        assertEquals(expectedLuminance, colorContrastRationCalculator.getRelativeLuminance(color), 1e-10);
+    }
+
+    @ParameterizedTest
+    @MethodSource("contrastRatioProvider")
+    void testGetContrastRatio(Color a, Color b, double expectedRatio) {
+        assertEquals(expectedRatio, colorContrastRationCalculator.getContrastRatio(a, b), 1e-10);
+    }
+}