Tests for MotionObservable.

Summary: 100% coverage.

Reviewers: miguelandres, O6 Material Motion Android platform reviewers, O2 Material Motion!, #material_motion

Reviewed By: miguelandres, O6 Material Motion Android platform reviewers

Subscribers: miguelandres

Tags: #material_motion

Differential Revision: http://codereview.cc/D2174

library/src/test/java/com/google/android/material/motion/streams/MotionObservableTests.java

@@ -0,0 +1,165 @@
+/*
+ * Copyright 2016-present The Material Motion Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.material.motion.streams;
+
+import android.app.Activity;
+import android.support.annotation.Nullable;
+import android.view.View;
+
+import com.google.android.material.motion.observable.IndefiniteObservable;
+import com.google.android.material.motion.streams.MotionObservable.MotionObserver;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.Robolectric;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static com.google.common.truth.Truth.assertThat;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(constants = BuildConfig.class, sdk = 21)
+public class MotionObservableTests {
+
+  private static final float E = 0.0001f;
+
+  private MotionObservable<Float> observable;
+
+  @Before
+  public void setUp() {
+    observable = new MotionObservable<>(
+      new IndefiniteObservable.Subscriber<MotionObserver<Float>>() {
+        @Nullable
+        @Override
+        public IndefiniteObservable.Unsubscriber subscribe(MotionObserver<Float> observer) {
+          observer.next(5f);
+          observer.state(MotionObservable.ACTIVE);
+          return null;
+        }
+      });
+  }
+
+  @Test
+  public void mapByHalf() {
+    observable.map(new MotionObservable.Transformation<Float, Float>() {
+      @Override
+      public Float transform(Float value) {
+        return value / 2f; // Half.
+      }
+    }).subscribe(new MotionObserver<Float>() {
+      @Override
+      public void next(Float value) {
+        assertThat(value).isWithin(E).of(2.5f);
+      }
+
+      @Override
+      public void state(@MotionObservable.MotionState int state) {
+        assertThat(state).isEqualTo(MotionObservable.ACTIVE);
+      }
+    });
+  }
+
+  @Test
+  public void filterAll() {
+    observable.filter(new MotionObservable.Predicate<Float>() {
+      @Override
+      public boolean evaluate(Float value) {
+        return false; // All are filtered.
+      }
+    }).subscribe(new MotionObserver<Float>() {
+      @Override
+      public void next(Float value) {
+        throw new AssertionError("Should never arrive here.");
+      }
+
+      @Override
+      public void state(@MotionObservable.MotionState int state) {
+        assertThat(state).isEqualTo(MotionObservable.ACTIVE);
+      }
+    }).unsubscribe();
+  }
+
+  @Test
+  public void filterNone() {
+    observable.filter(new MotionObservable.Predicate<Float>() {
+      @Override
+      public boolean evaluate(Float value) {
+        return true; // None are filtered.
+      }
+    }).subscribe(new MotionObserver<Float>() {
+      @Override
+      public void next(Float value) {
+        assertThat(value).isWithin(E).of(5f);
+      }
+
+      @Override
+      public void state(@MotionObservable.MotionState int state) {
+        assertThat(state).isEqualTo(MotionObservable.ACTIVE);
+      }
+    }).unsubscribe();
+    ;
+  }
+
+  @Test
+  public void writeUnscopedProperty() {
+    View target = new View(Robolectric.setupActivity(Activity.class));
+    target.setTranslationX(0);
+
+    observable.write(target, View.TRANSLATION_X).subscribe(new MotionObserver<Float>() {
+      @Override
+      public void next(Float value) {
+      }
+
+      @Override
+      public void state(@MotionObservable.MotionState int state) {
+      }
+    }).unsubscribe();
+    ;
+
+    assertThat(target.getTranslationX()).isWithin(E).of(5f);
+  }
+
+  @Test
+  public void writeInlineProperty() {
+    observable.write(new MotionObservable.InlineWritable<Float>() {
+      @Override
+      public void write(Float value) {
+        assertThat(value).isWithin(E).of(5f);
+      }
+    }).subscribe(new MotionObserver<Float>() {
+      @Override
+      public void next(Float value) {
+      }
+
+      @Override
+      public void state(@MotionObservable.MotionState int state) {
+      }
+    }).unsubscribe();
+  }
+
+  @Test
+  public void readInlineProperty() {
+    MotionObservable.InlineReadable<Float> reader = new MotionObservable.InlineReadable<Float>() {
+      @Override
+      public Float read() {
+        return 6f;
+      }
+    };
+
+    assertThat(reader.read()).isWithin(E).of(6f);
+  }
+}