Introduce FakeContextBuilder

/*

 * Copyright (C) 2018 The Android Open Source Project

 *

 * 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 android.view.textclassifier;

import static org.mockito.ArgumentMatchers.any;

import static org.mockito.ArgumentMatchers.anyInt;

import static org.mockito.Mockito.mock;

import static org.mockito.Mockito.when;

import android.content.ComponentName;

import android.content.Context;

import android.content.ContextWrapper;

import android.content.Intent;

import android.content.pm.ActivityInfo;

import android.content.pm.ApplicationInfo;

import android.content.pm.PackageManager;

import android.content.pm.ResolveInfo;

import android.support.test.InstrumentationRegistry;

import androidx.annotation.Nullable;

import com.google.common.base.Preconditions;

import org.mockito.stubbing.Answer;

import java.util.HashMap;

import java.util.Map;

import java.util.UUID;

/**

 * A builder used to build a fake context for testing.

 */

// TODO: Consider making public.

final class FakeContextBuilder {

    /**

     * A component name that can be used for tests.

     */

    public static final ComponentName DEFAULT_COMPONENT = new ComponentName("pkg", "cls");

    private final PackageManager mPackageManager;

    private final ContextWrapper mContext;

    private final Map<String, ComponentName> mComponents = new HashMap<>();

    private @Nullable ComponentName mAllIntentComponent;

    FakeContextBuilder() {

        mPackageManager = mock(PackageManager.class);

        when(mPackageManager.resolveActivity(any(Intent.class), anyInt())).thenReturn(null);

        mContext = new ContextWrapper(InstrumentationRegistry.getTargetContext()) {

            @Override

            public PackageManager getPackageManager() {

                return mPackageManager;

            }

        };

    }

    /**

     * Sets the component name of an activity to handle the specified intent action.

     * <p>

     * <strong>NOTE: </strong>By default, no component is set to handle any intent.

     */

    public FakeContextBuilder setIntentComponent(

            String intentAction, @Nullable ComponentName component) {

        Preconditions.checkNotNull(intentAction);

        mComponents.put(intentAction, component);

        return this;

    }

    /**

     * Sets the component name of an activity to handle all intents.

     * <p>

     * <strong>NOTE: </strong>By default, no component is set to handle any intent.

     */

    public FakeContextBuilder setAllIntentComponent(@Nullable ComponentName component) {

        mAllIntentComponent = component;

        return this;

    }

    /**

     * Builds and returns a fake context.

     */

    public Context build() {

        when(mPackageManager.resolveActivity(any(Intent.class), anyInt())).thenAnswer(

                (Answer<ResolveInfo>) invocation -> {

                    final String action = ((Intent) invocation.getArgument(0)).getAction();

                    final ComponentName component = mComponents.containsKey(action)

                            ? mComponents.get(action)

                            : mAllIntentComponent;

                    return getResolveInfo(component);

                });

        return mContext;

    }

    /**

     * Returns a component name with random package and class names.

     */

    public static ComponentName newComponent() {

        return new ComponentName(UUID.randomUUID().toString(), UUID.randomUUID().toString());

    }

    private static ResolveInfo getResolveInfo(ComponentName component) {

        final ResolveInfo info;

        if (component == null) {

            info = null;

        } else {

            // NOTE: If something breaks in TextClassifier because we expect more fields to be set

            // in here, just add them.

            info = new ResolveInfo();

            info.activityInfo = new ActivityInfo();

            info.activityInfo.packageName = component.getPackageName();

            info.activityInfo.name = component.getClassName();

            info.activityInfo.exported = true;

            info.activityInfo.applicationInfo = new ApplicationInfo();

            info.activityInfo.applicationInfo.icon = 0;

        }

        return info;

    }

}

import static org.junit.Assert.assertFalse;

import static org.junit.Assert.assertNotSame;

import static org.junit.Assert.assertTrue;

import static org.mockito.Matchers.argThat;

import static org.mockito.Mockito.any;

import static org.mockito.Mockito.anyInt;

import static org.mockito.Mockito.mock;

import static org.mockito.Mockito.when;

import android.content.Context;

import android.content.ContextWrapper;

import android.content.Intent;

import android.content.pm.PackageManager;

import android.content.pm.ResolveInfo;

import android.net.Uri;

import android.os.LocaleList;

import android.service.textclassifier.TextClassifierService;

import android.support.test.InstrumentationRegistry;

import org.junit.Before;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.mockito.ArgumentMatcher;

@SmallTest

@RunWith(AndroidJUnit4.class)

    @Test

    public void testCannotResolveIntent() {

        final PackageManager fakePackageMgr = mock(PackageManager.class);

        ResolveInfo validInfo = mContext.getPackageManager().resolveActivity(

                new Intent(Intent.ACTION_DIAL).setData(Uri.parse("tel:+12122537077")), 0);

        // Make packageManager fail when it gets the following intent:

        ArgumentMatcher<Intent> toFailIntent =

                intent -> intent.getAction().equals(Intent.ACTION_INSERT_OR_EDIT);

        when(fakePackageMgr.resolveActivity(any(Intent.class), anyInt())).thenReturn(validInfo);

        when(fakePackageMgr.resolveActivity(argThat(toFailIntent), anyInt())).thenReturn(null);

        ContextWrapper fakeContext = new ContextWrapper(mContext) {

            @Override

            public PackageManager getPackageManager() {

                return fakePackageMgr;

            }

        };

        Context fakeContext = new FakeContextBuilder()

                .setAllIntentComponent(FakeContextBuilder.DEFAULT_COMPONENT)

                .setIntentComponent(Intent.ACTION_INSERT_OR_EDIT, null)

                .build();

        TextClassifier fallback = TextClassifier.NO_OP;

        TextClassifier classifier = new TextClassifierImpl(