tests/net/java/com/android/server/connectivity/NetworkRankerTest.kt

/*
 * 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.connectivity

import android.net.ConnectivityManager.TYPE_WIFI
import android.net.LinkProperties
import android.net.Network
import android.net.NetworkAgentConfig
import android.net.NetworkCapabilities
import android.net.NetworkInfo
import android.net.NetworkRequest
import android.net.NetworkScore
import androidx.test.filters.SmallTest
import androidx.test.runner.AndroidJUnit4
import org.junit.Test
import org.junit.runner.RunWith
import org.mockito.ArgumentMatchers.any
import org.mockito.Mockito.doReturn
import org.mockito.Mockito.mock
import kotlin.test.assertEquals
import kotlin.test.assertNull

@RunWith(AndroidJUnit4::class)
@SmallTest
class NetworkRankerTest {
    private val ranker = NetworkRanker()

    private fun makeNai(satisfy: Boolean, score: Int) = object : NetworkAgentInfo(
            null /* messenger */,
            null /* asyncChannel*/,
            Network(100),
            NetworkInfo(TYPE_WIFI, 0 /* subtype */, "" /* typename */, "" /* subtypename */),
            LinkProperties(),
            NetworkCapabilities(),
            NetworkScore.Builder().setLegacyScore(score).build(),
            null /* context */,
            null /* handler */,
            NetworkAgentConfig(),
            null /* connectivityService */,
            null /* netd */,
            null /* dnsResolver */,
            null /* networkManagementService */,
            0 /* factorySerialNumber */) {
        override fun satisfies(request: NetworkRequest?): Boolean = satisfy
        override fun getCurrentScore(): Int = score
    }

    @Test
    fun testGetBestNetwork() {
        val scores = listOf(20, 50, 90, 60, 23, 68)
        val nais = scores.map { makeNai(true, it) }
        val bestNetwork = nais[2] // The one with the top score
        val someRequest = mock(NetworkRequest::class.java)
        assertEquals(bestNetwork, ranker.getBestNetwork(someRequest, nais))
    }

    @Test
    fun testIgnoreNonSatisfying() {
        val nais = listOf(makeNai(true, 20), makeNai(true, 50), makeNai(false, 90),
                makeNai(false, 60), makeNai(true, 23), makeNai(false, 68))
        val bestNetwork = nais[1] // Top score that's satisfying
        val someRequest = mock(NetworkRequest::class.java)
        assertEquals(bestNetwork, ranker.getBestNetwork(someRequest, nais))
    }

    @Test
    fun testNoMatch() {
        val nais = listOf(makeNai(false, 20), makeNai(false, 50), makeNai(false, 90))
        val someRequest = mock(NetworkRequest::class.java)
        assertNull(ranker.getBestNetwork(someRequest, nais))
    }

    @Test
    fun testEmpty() {
        val someRequest = mock(NetworkRequest::class.java)
        assertNull(ranker.getBestNetwork(someRequest, emptyList()))
    }

    // Make sure the ranker is "stable" (as in stable sort), that is, it always returns the FIRST
    // network satisfying the request if multiple of them have the same score.
    @Test
    fun testStable() {
        val nais1 = listOf(makeNai(true, 30), makeNai(true, 30), makeNai(true, 30),
                makeNai(true, 30), makeNai(true, 30), makeNai(true, 30))
        val someRequest = mock(NetworkRequest::class.java)
        assertEquals(nais1[0], ranker.getBestNetwork(someRequest, nais1))

        val nais2 = listOf(makeNai(true, 30), makeNai(true, 50), makeNai(true, 20),
                makeNai(true, 50), makeNai(true, 50), makeNai(true, 40))
        assertEquals(nais2[1], ranker.getBestNetwork(someRequest, nais2))
    }
}