Kotlin Multiplatform Workshop

androidMain_UserPreferenceImpl.kt

package com.kithub.core.data

import android.content.Context.MODE_PRIVATE
import androidx.core.content.edit
import com.kithub.core.AndroidAppContext

actual class UserPreferenceImpl : UserPreference {
    private val sharedPreference
        get() = AndroidAppContext.app.getSharedPreferences("UserPreference", MODE_PRIVATE)

    override var username: String
        get() = sharedPreference.getString("username", "").orEmpty()
        set(value) {
            sharedPreference.edit {
                putString("username", value)
            }
        }
}

iosMain_UserPreferenceImpl.kt

package com.kithub.core.data

import platform.Foundation.NSUserDefaults
import platform.Foundation.setValue

actual class UserPreferenceImpl : UserPreference {

    private val userDefaults get() = NSUserDefaults(suiteName = "UserPreference")

    override var username: String
        get() = userDefaults.stringForKey("username").orEmpty()
        set(value) {
            userDefaults.setValue(value, forKey =  "username")
        }
}

RepoDetailViewModel.kt

package com.kithub.core.viewmodel.repodetail

import com.kithub.core.data.GithubApi
import com.kithub.core.data.UserPreference
import com.kithub.core.viewmodel.KViewModel
import kotlinx.coroutines.launch

data class RepoDetailViewState(
    val loading: Boolean = true,
    val name: String = "",
    val descriptionText: String = "",
    val language: String = "",
    val sshUrl: String = "",
    val starCount: Int = 0,
    val contributors: List<ContributorItem> = emptyList()
)

data class ContributorItem(
    val name: String = "",
    val contributions: Int = 0,
    val avatarUrl: String = ""
)

class RepoDetailViewModel(
    private val userPreference: UserPreference,
    private val githubApi: GithubApi
) : KViewModel<RepoDetailViewState>(RepoDetailViewState()) {
    fun refresh(repoName: String) {
        launch {
            try {
                setState { copy(loading = true) }
                val contributors = githubApi.getContributors(userPreference.username, repoName)
                val repoDetail = githubApi.getUserRepoDetail(userPreference.username, repoName)

                setState {
                    copy(loading = false,
                        name = repoDetail.name.orEmpty(),
                        descriptionText = repoDetail.description.orEmpty(),
                        language = repoDetail.language.orEmpty(),
                        starCount = repoDetail.stargazersCount ?: 0,
                        sshUrl = repoDetail.sshUrl.orEmpty(),
                        contributors = contributors.map {
                            ContributorItem(
                                name = it.login.orEmpty(),
                                avatarUrl = it.avatarUrl.orEmpty(),
                                contributions = it.contributions ?: 0
                            )
                        })
                }

            } catch (e: Throwable) {
                setState { copy(loading = false) }
                setError(e)
            }
        }
    }
}

RepoDetailViewModelTest.kt

package com.kithub.core.viewmodel.repodetail

import com.kithub.core.assertState
import com.kithub.core.common.coroutine.ApplicationDispatcher
import com.kithub.core.common.coroutine.TestDispatcher
import com.kithub.core.common.kreactive.test
import com.kithub.core.data.ContributorEntity
import com.kithub.core.data.GithubApi
import com.kithub.core.data.RepoDetailEntity
import com.kithub.core.data.UserPreference
import io.mockk.coEvery
import io.mockk.every
import io.mockk.mockk
import kotlinx.coroutines.InternalCoroutinesApi
import org.junit.Test
import kotlin.test.assertTrue


@UseExperimental(InternalCoroutinesApi::class)
class RepoDetailViewModelTest {
    val userPreference = mockk<UserPreference>(relaxed = true)
    val githubApi = mockk<GithubApi>(relaxed = true)

    val viewModel = RepoDetailViewModel(userPreference, githubApi)

    val state = viewModel.state.test()
    val error = viewModel.error.test()

    init {
        ApplicationDispatcher = TestDispatcher
    }

    @Test
    fun refresh() {
        val repoDetailEntity = RepoDetailEntity(
            name = "ktor",
            description = "http library",
            language = "kotlin",
            sshUrl = "ssh.url",
            stargazersCount = 2000
        )

        val contributorEntities = listOf(
            ContributorEntity(
                login = "alice",
                contributions = 120,
                avatarUrl = "avatar.url"
            )
        )

        every { userPreference.username } returns "kotlin"
        coEvery { githubApi.getContributors("kotlin", "ktor") } returns contributorEntities
        coEvery { githubApi.getUserRepoDetail("kotlin", "ktor") } returns repoDetailEntity

        viewModel.refresh("ktor")

        assertTrue { error.values.isEmpty() }
        state.assertState(
            RepoDetailViewState(),
            { copy(loading = true) },
            {
                copy(
                    loading = false,
                    name = "ktor",
                    descriptionText = "http library",
                    starCount = 2000,
                    sshUrl = "ssh.url",
                    language = "kotlin",
                    contributors = listOf(
                        ContributorItem(
                            name = "alice",
                            contributions = 120,
                            avatarUrl = "avatar.url"
                        )
                    )
                )
            }
        )
    }
}

RepoListViewModel.kt

package com.kithub.core.viewmodel.repolist

import com.kithub.core.data.GithubApi
import com.kithub.core.data.UserPreference
import com.kithub.core.viewmodel.KViewModel
import kotlinx.coroutines.launch


data class RepoListViewState(
    val loading: Boolean = true,
    val username: String = "",
    val displayName: String = "",
    val avatarUrl: String = "",
    val repos: List<RepoItem> = emptyList()
)

data class RepoItem(
    val name: String,
    val descriptionText: String, // Don't use val description: String because iOS can't see it
    val starCount: Int
)

class RepoListViewModel(
    private val userPreference: UserPreference,
    private val githubApi: GithubApi
) : KViewModel<RepoListViewState>(RepoListViewState()) {
    fun refresh() {
        launch {
            try {
                setState { copy(loading = true) }

                val userEntity = githubApi.getUser(username = userPreference.username)
                val repoEntities = githubApi.getUserRepos(username = userPreference.username)

                setState {
                    copy(
                        loading = false,
                        username = userEntity.login ?: "",
                        displayName = userEntity.name.orEmpty(),
                        avatarUrl = userEntity.avatarUrl.orEmpty(),
                        repos = repoEntities.map {
                            RepoItem(
                                name = it.name.orEmpty(),
                                descriptionText = it.description.orEmpty(),
                                starCount = it.stargazersCount ?: 0
                            )
                        }
                    )
                }
            } catch (e: Throwable) {
                setState { copy(loading = false) }
                setError(e)
            }
        }
    }

    fun logout() {
        userPreference.username = ""
    }
}

RepoListViewModelTest.kt

package com.kithub.core.viewmodel.repolist

import com.kithub.core.assertState
import com.kithub.core.common.coroutine.ApplicationDispatcher
import com.kithub.core.common.coroutine.TestDispatcher
import com.kithub.core.common.kreactive.test
import com.kithub.core.data.GithubApi
import com.kithub.core.data.RepoEntity
import com.kithub.core.data.UserEntity
import com.kithub.core.data.UserPreference
import io.mockk.coEvery
import io.mockk.every
import io.mockk.mockk
import io.mockk.verify
import kotlinx.coroutines.InternalCoroutinesApi
import kotlin.test.Test
import kotlin.test.assertTrue

@UseExperimental(InternalCoroutinesApi::class)
class RepoListViewModelTest {

    val userPreference = mockk<UserPreference>(relaxed = true)
    val githubApi = mockk<GithubApi>(relaxed = true)

    val viewModel = RepoListViewModel(userPreference, githubApi)

    val state = viewModel.state.test()
    val error = viewModel.error.test()

    init {
        ApplicationDispatcher = TestDispatcher
    }

    @Test
    fun refresh() {
        val userEntity = UserEntity(
            login = "kotlin",
            name = "Kotlin Lang",
            avatarUrl = "www.google.com"
        )

        val repoEntities = listOf(
            RepoEntity(
                name = "ktor",
                description = "Http library",
                stargazersCount = 9999
            )
        )
        every { userPreference.username } returns "kotlin"
        coEvery { githubApi.getUser("kotlin") } returns userEntity
        coEvery { githubApi.getUserRepos("kotlin") } returns repoEntities

        viewModel.refresh()

        assertTrue { error.values.isEmpty() }
        state.assertState(RepoListViewState(),
            { copy(loading = true) },
            {
                copy(
                    loading = false,
                    username = "kotlin",
                    avatarUrl = "www.google.com",
                    displayName = "Kotlin Lang",
                    repos = listOf(
                        RepoItem(
                            name = "ktor",
                            descriptionText = "Http library",
                            starCount = 9999
                        )
                    )
                )
            }
        )
    }

    @Test
    fun logout() {
        viewModel.logout()

        verify { userPreference.username = "" }
    }
}