[examples] AddressableLED: Add unit test (#4779)

wpilibcExamples/src/test/cpp/examples/AddressableLED/cpp/RainbowTest.cpp

@@ -0,0 +1,53 @@
+// 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.
+
+#include <fmt/format.h>
+#include <gtest/gtest.h>
+
+#include <array>
+
+#include <frc/AddressableLED.h>
+#include <frc/simulation/AddressableLEDSim.h>
+#include <frc/util/Color.h>
+#include <frc/util/Color8Bit.h>
+#include <hal/AddressableLEDTypes.h>
+
+#include "Robot.h"
+
+void AssertIndexColor(std::array<frc::AddressableLED::LEDData, 60> data,
+                      int index, int hue, int saturation, int value);
+
+TEST(RainbowTest, RainbowPattern) {
+  Robot robot;
+  robot.RobotInit();
+  frc::sim::AddressableLEDSim ledSim =
+      frc::sim::AddressableLEDSim::CreateForChannel(9);
+  EXPECT_TRUE(ledSim.GetRunning());
+  EXPECT_EQ(60, ledSim.GetLength());
+
+  auto rainbowFirstPixelHue = 0;
+  std::array<frc::AddressableLED::LEDData, 60> data;
+  for (int iteration = 0; iteration < 100; iteration++) {
+    SCOPED_TRACE(fmt::format("Iteration {} of 100", iteration));
+    robot.RobotPeriodic();
+    ledSim.GetData(data.data());
+    for (int i = 0; i < 60; i++) {
+      SCOPED_TRACE(fmt::format("LED {} of 60", i));
+      auto hue = (rainbowFirstPixelHue + (i * 180 / 60)) % 180;
+      AssertIndexColor(data, i, hue, 255, 128);
+    }
+    rainbowFirstPixelHue += 3;
+    rainbowFirstPixelHue %= 180;
+  }
+}
+
+void AssertIndexColor(std::array<frc::AddressableLED::LEDData, 60> data,
+                      int index, int hue, int saturation, int value) {
+  frc::Color8Bit color{frc::Color::FromHSV(hue, saturation, value)};
+
+  EXPECT_EQ(0, data[index].padding);
+  EXPECT_EQ(color.red, data[index].r & 0xFF);
+  EXPECT_EQ(color.green, data[index].g & 0xFF);
+  EXPECT_EQ(color.blue, data[index].b & 0xFF);
+}

wpilibcExamples/src/test/cpp/examples/AddressableLED/cpp/main.cpp

@@ -0,0 +1,17 @@
+// 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.
+
+#include <hal/HALBase.h>
+
+#include "gtest/gtest.h"
+
+/**
+ * Runs all unit tests.
+ */
+int main(int argc, char** argv) {
+  HAL_Initialize(500, 0);
+  ::testing::InitGoogleTest(&argc, argv);
+  int ret = RUN_ALL_TESTS();
+  return ret;
+}