Refactor application class

app/src/androidTest/kotlin/org/koitharu/kotatsu/SampleData.kt

@@ -0,0 +1,54 @@
+package org.koitharu.kotatsu
+
+import androidx.test.platform.app.InstrumentationRegistry
+import com.squareup.moshi.*
+import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
+import okio.buffer
+import okio.source
+import org.koitharu.kotatsu.core.model.FavouriteCategory
+import org.koitharu.kotatsu.parsers.model.Manga
+import java.util.*
+import kotlin.reflect.KClass
+
+object SampleData {
+
+	private val moshi = Moshi.Builder()
+		.add(DateAdapter())
+		.add(KotlinJsonAdapterFactory())
+		.build()
+
+	val manga: Manga = loadAsset("manga/header.json", Manga::class)
+
+	val mangaDetails: Manga = loadAsset("manga/full.json", Manga::class)
+
+	val tag = mangaDetails.tags.elementAt(2)
+
+	val chapter = checkNotNull(mangaDetails.chapters)[2]
+
+	val favouriteCategory: FavouriteCategory = loadAsset("categories/simple.json", FavouriteCategory::class)
+
+	fun <T : Any> loadAsset(name: String, cls: KClass<T>): T {
+		val assets = InstrumentationRegistry.getInstrumentation().context.assets
+		return assets.open(name).use {
+			moshi.adapter(cls.java).fromJson(it.source().buffer())
+		} ?: throw RuntimeException("Cannot read asset from json \"$name\"")
+	}
+
+	private class DateAdapter : JsonAdapter<Date>() {
+
+		@FromJson
+		override fun fromJson(reader: JsonReader): Date? {
+			val ms = reader.nextLong()
+			return if (ms == 0L) {
+				null
+			} else {
+				Date(ms)
+			}
+		}
+
+		@ToJson
+		override fun toJson(writer: JsonWriter, value: Date?) {
+			writer.value(value?.time ?: 0L)
+		}
+	}
+}