Add initial unit tests for HdmiCecMessageValidator

/*

 * Copyright (C) 2020 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 com.android.server.hdmi;

import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_DESTINATION;

import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_PARAMETER_SHORT;

import static com.android.server.hdmi.HdmiCecMessageValidator.ERROR_SOURCE;

import static com.android.server.hdmi.HdmiCecMessageValidator.OK;

import static com.google.common.truth.Truth.assertThat;

import android.platform.test.annotations.Presubmit;

import androidx.test.InstrumentationRegistry;

import androidx.test.filters.SmallTest;

import com.google.common.truth.IntegerSubject;

import org.junit.Before;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.junit.runners.JUnit4;

/** Tests for {@link com.android.server.hdmi.HdmiCecMessageValidator} class. */

@SmallTest

@Presubmit

@RunWith(JUnit4.class)

public class HdmiCecMessageValidatorTest {

    private HdmiCecMessageValidator mHdmiCecMessageValidator;

    @Before

    public void setUp() throws Exception {

        HdmiControlService mHdmiControlService = new HdmiControlService(

                InstrumentationRegistry.getTargetContext());

        mHdmiCecMessageValidator = new HdmiCecMessageValidator(mHdmiControlService);

    }

    @Test

    public void isValid_giveDevicePowerStatus() {

        assertMessageValidity("04:8F").isEqualTo(OK);

        assertMessageValidity("0F:8F").isEqualTo(ERROR_DESTINATION);

        assertMessageValidity("F4:8F").isEqualTo(ERROR_SOURCE);

    }

    @Test

    public void isValid_reportPowerStatus() {

        assertMessageValidity("04:90:00").isEqualTo(OK);

        assertMessageValidity("0F:90:00").isEqualTo(ERROR_DESTINATION);

        assertMessageValidity("F0:90").isEqualTo(ERROR_SOURCE);

        assertMessageValidity("04:90").isEqualTo(ERROR_PARAMETER_SHORT);

    }

    private IntegerSubject assertMessageValidity(String message) {

        return assertThat(mHdmiCecMessageValidator.isValid(buildMessage(message)));

    }

    /**

     * Build a CEC message from a hex byte string with bytes separated by {@code :}.

     *

     * <p>This format is used by both cec-client and www.cec-o-matic.com

     */

    private static HdmiCecMessage buildMessage(String message) {

        String[] parts = message.split(":");

        int src = Integer.parseInt(parts[0].substring(0, 1), 16);

        int dest = Integer.parseInt(parts[0].substring(1, 2), 16);

        int opcode = Integer.parseInt(parts[1], 16);

        byte[] params = new byte[parts.length - 2];

        for (int i = 0; i < params.length; i++) {

            params[i] = (byte) Integer.parseInt(parts[i + 2], 16);

        }

        return new HdmiCecMessage(src, dest, opcode, params);

    }

}