Add GradientColorTest

lottie/src/test/java/com/airbnb/lottie/model/content/GradientColorTest.java

@@ -0,0 +1,46 @@
+package com.airbnb.lottie.model.content;
+
+import junit.framework.TestCase;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+public class GradientColorTest extends TestCase {
+
+  private final GradientColor start = new GradientColor(new float[]{0f, 1f}, new int[]{0xFF000000, 0xFF020202});
+
+  private final GradientColor end = new GradientColor(new float[]{0f, 1f}, new int[]{0xFF020202, 0xFF040404});
+
+  private final GradientColor gradient = new GradientColor(new float[2], new int[2]);
+
+  @Test
+  public void testLerpWithOutOfBoundsNegativeProgress() {
+    gradient.lerp(start, end, -42f);
+    assertEquals(start, gradient);
+  }
+
+  @Test
+  public void testLerpWithZeroProgress() {
+    gradient.lerp(start, end, 0f);
+    assertEquals(start, gradient);
+  }
+
+  @Test
+  public void testLerpWithHalfProgress() {
+    gradient.lerp(start, end, 0.5f);
+    GradientColor half = new GradientColor(new float[]{0f, 1f}, new int[]{0xFF010101, 0xFF030303});
+    assertEquals(half, gradient);
+  }
+
+  @Test
+  public void testLerpWithOneProgress() {
+    gradient.lerp(start, end, 1f);
+    assertEquals(end, gradient);
+  }
+
+  @Test
+  public void testLerpWithOutOfBoundsPositiveProgress() {
+    gradient.lerp(start, end, 42f);
+    assertEquals(end, gradient);
+  }
+}