1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package com.android.tv.common.feature;
18 
19 import android.content.Context;
20 import android.support.annotation.VisibleForTesting;
21 import android.util.Log;
22 import com.android.tv.common.util.CommonUtils;
23 
24 /**
25  * When run in a test harness this feature can be turned on or off, overriding the normal value.
26  *
27  * <p><b>Warning</b> making a feature testable will cause the code to stay in the APK and could leak
28  * unreleased features.
29  */
30 public class TestableFeature implements Feature {
31     private static final String TAG = "TestableFeature";
32     private static final String DETAIL_MESSAGE =
33             "TestableFeatures should only be changed in tests.";
34 
35     private final Feature mDelegate;
36     private Boolean mTestValue = null;
37 
38     /** Creates testable feature. */
createTestableFeature(Feature delegate)39     public static TestableFeature createTestableFeature(Feature delegate) {
40         return new TestableFeature(delegate);
41     }
42 
43     /** Creates testable feature with initial value. */
createTestableFeature(Feature delegate, Boolean initialValue)44     public static TestableFeature createTestableFeature(Feature delegate, Boolean initialValue) {
45         return new TestableFeature(delegate, initialValue);
46     }
47 
TestableFeature(Feature delegate)48     private TestableFeature(Feature delegate) {
49         mDelegate = delegate;
50     }
51 
TestableFeature(Feature delegate, Boolean initialValue)52     private TestableFeature(Feature delegate, Boolean initialValue) {
53         mDelegate = delegate;
54         mTestValue = initialValue;
55     }
56 
57     @VisibleForTesting
enableForTest()58     public void enableForTest() {
59         if (!CommonUtils.isRunningInTest()) {
60             Log.e(TAG, "Not enabling for test:" + this, new IllegalStateException(DETAIL_MESSAGE));
61         } else {
62             mTestValue = true;
63         }
64     }
65 
66     @VisibleForTesting
disableForTests()67     public void disableForTests() {
68         if (!CommonUtils.isRunningInTest()) {
69             Log.e(
70                     TAG,
71                     "Not disabling for test: " + this,
72                     new IllegalStateException(DETAIL_MESSAGE));
73         } else {
74             mTestValue = false;
75         }
76     }
77 
78     @VisibleForTesting
resetForTests()79     public void resetForTests() {
80         if (!CommonUtils.isRunningInTest()) {
81             Log.e(TAG, "Not resetting feature: " + this, new IllegalStateException(DETAIL_MESSAGE));
82         } else {
83             mTestValue = null;
84         }
85     }
86 
87     @Override
isEnabled(Context context)88     public boolean isEnabled(Context context) {
89         if (CommonUtils.isRunningInTest() && mTestValue != null) {
90             return mTestValue;
91         }
92         return mDelegate.isEnabled(context);
93     }
94 
95     @Override
toString()96     public String toString() {
97         String msg = mDelegate.toString();
98         if (CommonUtils.isRunningInTest()) {
99             if (mTestValue == null) {
100                 msg = "Testable Feature is unchanged: " + msg;
101             } else {
102                 msg = "Testable Feature is " + (mTestValue ? "on" : "off") + " was " + msg;
103             }
104         }
105         return msg;
106     }
107 }
108