fill EXposedPostsAPICommonTests

exposed/src/test/kotlin/com/insanusmokrassar/postssystem/core/exposed/ExposedPostsAPICommonTests.kt

@@ -0,0 +1,64 @@
+package com.insanusmokrassar.postssystem.core.exposed
+
+import com.insanusmokrassar.postssystem.core.post.SimplePost
+import kotlinx.coroutines.runBlocking
+import org.jetbrains.exposed.sql.Database
+import org.jetbrains.exposed.sql.transactions.transactionManager
+import org.junit.jupiter.api.*
+import java.io.File
+import java.sql.Connection
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class ExposedPostsAPICommonTests {
+    private val tempFolder = System.getProperty("java.io.tmpdir")!!
+
+    private val numberOfDatabases = 8
+    private lateinit var databaseFiles: List<File>
+    private lateinit var apis: List<ExposedPostsAPI>
+
+    @BeforeAll
+    fun prepare() {
+        databaseFiles = (0 until numberOfDatabases).map {
+            File("$tempFolder/ExposedPostsAPICommonTestsDB$it.db")
+        }
+        apis = databaseFiles.map {
+            ExposedPostsAPI(
+                Database.Companion.connect("jdbc:sqlite:${it.absolutePath}", driver = "org.sqlite.JDBC").also {
+                    it.transactionManager.defaultIsolationLevel = Connection.TRANSACTION_SERIALIZABLE
+                }
+            )
+        }
+    }
+
+    @Test
+    fun `Test that it is possible to use several different databases at one time`() {
+        val posts = apis.mapIndexed { i, api ->
+            val content = runBlocking { api.createPost(SimplePost(listOf(i.toString()))) }
+            assert(content != null)
+            assert(runBlocking { api.getPostsIds().size == 1 })
+            content!!
+        }
+
+        posts.forEachIndexed { i, post ->
+            apis.forEachIndexed { j, api ->
+                assert(
+                    runBlocking {
+                        api.getPostById(post.id) == (if (i != j) null else post)
+                    }
+                )
+                assert(
+                    runBlocking {
+                        api.deletePost(post.id) == (i == j)
+                    }
+                )
+            }
+        }
+    }
+
+    @AfterAll
+    fun `Close and delete databases`() {
+        databaseFiles.forEach {
+            it.delete()
+        }
+    }
+}