Added test

Author: samruston

lib/javatests/com/google/android/material/button/MaterialButtonTest.java

@@ -24,12 +24,15 @@
 import com.google.android.material.shape.CornerTreatment;
 import com.google.android.material.shape.CutCornerTreatment;
 import com.google.android.material.shape.ShapeAppearanceModel;
+import androidx.core.content.ContextCompat;
 import androidx.test.core.app.ApplicationProvider;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.internal.DoNotInstrument;
+import android.graphics.drawable.Drawable;
+import android.view.View.MeasureSpec;
 
 /** Tests for {@link com.google.android.material.button.MaterialButton}. */
 @RunWith(RobolectricTestRunner.class)
@@ -91,6 +94,27 @@ public void testGetShapeAppearanceModel() {
         materialButton.getShapeAppearanceModel(), CUT_CORNER_FAMILY_CLASS);
   }
 
+  @Test
+  public void setIcon_IconUpdated_whenCalledTwice() {
+    MaterialButton materialButton = new MaterialButton(context);
+    materialButton.setText("test");
+    int measureSpec =
+        MeasureSpec.makeMeasureSpec(200, MeasureSpec.AT_MOST);
+
+    Drawable drawable1 = ContextCompat.getDrawable(context, android.R.drawable.btn_plus);
+    materialButton.setIcon(drawable1);
+    materialButton.setIconGravity(MaterialButton.ICON_GRAVITY_START);
+    materialButton.measure(measureSpec, measureSpec);
+
+    assertThat(materialButton.getIcon()).isEqualTo(drawable1);
+
+    Drawable drawable2 = ContextCompat.getDrawable(context, android.R.drawable.btn_minus);
+    materialButton.setIcon(drawable2);
+    materialButton.measure(measureSpec, measureSpec);
+
+    assertThat(materialButton.getIcon()).isEqualTo(drawable2);
+  }
+
   private void assertThatCornerFamilyMatches(
       ShapeAppearanceModel shapeAppearanceModel,
       Class<? extends CornerTreatment> expectedCornerFamily) {