[wpilib] Add hex string constructor to Color and Color8Bit (#5063)

Co-authored-by: Tyler Veness <calcmogul@gmail.com>

wpilibj/src/test/java/edu/wpi/first/wpilibj/util/Color8BitTest.java

@@ -0,0 +1,65 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class Color8BitTest {
+  @Test
+  void testConstructDefault() {
+    var color = new Color8Bit();
+
+    assertEquals(0, color.red);
+    assertEquals(0, color.green);
+    assertEquals(0, color.blue);
+  }
+
+  @Test
+  void testConstructFromInts() {
+    var color = new Color8Bit(255, 128, 64);
+
+    assertEquals(255, color.red);
+    assertEquals(128, color.green);
+    assertEquals(64, color.blue);
+  }
+
+  @Test
+  void testConstructFromColor() {
+    var color = new Color8Bit(new Color(255, 128, 64));
+
+    assertEquals(255, color.red);
+    assertEquals(128, color.green);
+    assertEquals(64, color.blue);
+  }
+
+  @Test
+  void testConstructFromHexString() {
+    var color = new Color8Bit("#FF8040");
+
+    assertEquals(255, color.red);
+    assertEquals(128, color.green);
+    assertEquals(64, color.blue);
+
+    // No leading #
+    assertThrows(IllegalArgumentException.class, () -> new Color8Bit("112233"));
+
+    // Too long
+    assertThrows(IllegalArgumentException.class, () -> new Color8Bit("#11223344"));
+
+    // Invalid hex characters
+    assertThrows(IllegalArgumentException.class, () -> new Color8Bit("#$$$$$$"));
+  }
+
+  @Test
+  void testToHexString() {
+    var color = new Color8Bit(255, 128, 64);
+
+    assertEquals("#FF8040", color.toHexString());
+    assertEquals("#FF8040", color.toString());
+  }
+}

wpilibj/src/test/java/edu/wpi/first/wpilibj/util/ColorTest.java

@@ -0,0 +1,74 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package edu.wpi.first.wpilibj.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class ColorTest {
+  @Test
+  void testConstructDefault() {
+    var color = new Color();
+
+    assertEquals(0.0, color.red);
+    assertEquals(0.0, color.green);
+    assertEquals(0.0, color.blue);
+  }
+
+  @Test
+  void testConstructFromDoubles() {
+    var color = new Color(1.0, 0.5, 0.25);
+
+    assertEquals(1.0, color.red, 1e-2);
+    assertEquals(0.5, color.green, 1e-2);
+    assertEquals(0.25, color.blue, 1e-2);
+  }
+
+  @Test
+  void testConstructFromInts() {
+    var color = new Color(255, 128, 64);
+
+    assertEquals(1.0, color.red, 1e-2);
+    assertEquals(0.5, color.green, 1e-2);
+    assertEquals(0.25, color.blue, 1e-2);
+  }
+
+  @Test
+  void testConstructFromHexString() {
+    var color = new Color("#FF8040");
+
+    assertEquals(1.0, color.red, 1e-2);
+    assertEquals(0.5, color.green, 1e-2);
+    assertEquals(0.25, color.blue, 1e-2);
+
+    // No leading #
+    assertThrows(IllegalArgumentException.class, () -> new Color("112233"));
+
+    // Too long
+    assertThrows(IllegalArgumentException.class, () -> new Color("#11223344"));
+
+    // Invalid hex characters
+    assertThrows(IllegalArgumentException.class, () -> new Color("#$$$$$$"));
+  }
+
+  @Test
+  void testFromHSV() {
+    var color = Color.fromHSV(90, 128, 64);
+
+    assertEquals(0.125732421875, color.red);
+    assertEquals(0.251220703125, color.green);
+    assertEquals(0.251220703125, color.blue);
+  }
+
+  @Test
+  void testToHexString() {
+    var color = new Color(255, 128, 64);
+
+    assertEquals("#FF8040", color.toHexString());
+    assertEquals("#FF8040", color.toString());
+  }
+}