Gson as content negotiator (#26)

fractalliter · web-flow · commit 94a139b34ca1 · 2024-04-14T00:52:07.000+02:00
* remove gson serializer

* remove gson serializer from exceptions

* remove gson serializer from test

* remove gson serializer from configs

* remove gson serializer from integration tests

* add gson as content negotiator

* add quality badges
diff --git a/README.md b/README.md
@@ -2,6 +2,12 @@
 
 Here lays a Kotlin web project with Ktor framework, Postgres database, and JWT Authentication.
 
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=fractalliter_ktor-postgres-backend&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=fractalliter_ktor-postgres-backend)
+[![Bugs](https://sonarcloud.io/api/project_badges/measure?project=fractalliter_ktor-postgres-backend&metric=bugs)](https://sonarcloud.io/summary/new_code?id=fractalliter_ktor-postgres-backend)
+[![Code Smells](https://sonarcloud.io/api/project_badges/measure?project=fractalliter_ktor-postgres-backend&metric=code_smells)](https://sonarcloud.io/summary/new_code?id=fractalliter_ktor-postgres-backend)
+[![Duplicated Lines (%)](https://sonarcloud.io/api/project_badges/measure?project=fractalliter_ktor-postgres-backend&metric=duplicated_lines_density)](https://sonarcloud.io/summary/new_code?id=fractalliter_ktor-postgres-backend)
+[![Vulnerabilities](https://sonarcloud.io/api/project_badges/measure?project=fractalliter_ktor-postgres-backend&metric=vulnerabilities)](https://sonarcloud.io/summary/new_code?id=fractalliter_ktor-postgres-backend)
+
 The project comprises the following ingredients:
 
 - [Ktor](https://ktor.io/) server
diff --git a/build.gradle.kts b/build.gradle.kts
@@ -3,7 +3,6 @@ val kotlin_version: String by project
 val logback_version: String by project
 val exposed_version: String by project
 val database_driver_version: String by project
-val gson_version: String by project
 val jbcrypt_version: String by project
 val hikaricp_version: String by project
 val redis_version: String by project
@@ -51,14 +50,14 @@ dependencies {
     implementation("org.jetbrains.exposed:exposed-jdbc:$exposed_version")
     // add database driver below, default is postgres
     implementation("org.postgresql:postgresql:$database_driver_version")
-    implementation("com.google.code.gson:gson:$gson_version")
     implementation("org.mindrot:jbcrypt:$jbcrypt_version")
     implementation("io.github.crackthecodeabhi:kreds:$redis_version")
     implementation("com.zaxxer:HikariCP:$hikaricp_version")
+    implementation("io.ktor:ktor-client-content-negotiation:$ktor_version")
     implementation("io.ktor:ktor-server-content-negotiation-jvm:$ktor_version")
     implementation("io.ktor:ktor-client-content-negotiation:$ktor_version")
     implementation("io.ktor:ktor-server-core-jvm:$ktor_version")
-    implementation("io.ktor:ktor-serialization-kotlinx-json-jvm:$ktor_version")
+    implementation("io.ktor:ktor-serialization-gson:$ktor_version")
     implementation("io.ktor:ktor-server-netty-jvm:$ktor_version")
     implementation("io.ktor:ktor-server-auth:$ktor_version")
     implementation("io.ktor:ktor-server-status-pages:$ktor_version")
diff --git a/gradle.properties b/gradle.properties
@@ -5,7 +5,6 @@ kotlin.code.style=official
 exposed_version=0.37.3
 # Postgresql driver version, it can be any db driver. Also change the equivalent dependency
 database_driver_version=42.5.1
-gson_version=2.9.0
 jbcrypt_version=0.4
 hikaricp_version=5.0.1
 redis_version=0.8
diff --git a/src/main/kotlin/com/personia/dao/node/NodeDaoFacade.kt b/src/main/kotlin/com/personia/dao/node/NodeDaoFacade.kt
@@ -1,6 +1,6 @@
 package com.personia.dao.node
 
-import com.personia.models.Node
+import com.personia.dto.Node
 
 interface NodeDaoFacade {
     suspend fun allConnections(): List<Node>
diff --git a/src/main/kotlin/com/personia/dao/node/NodeDaoImpl.kt b/src/main/kotlin/com/personia/dao/node/NodeDaoImpl.kt
@@ -1,7 +1,7 @@
 package com.personia.dao.node
 
 import com.personia.dao.DatabaseFactory.dbQuery
-import com.personia.models.Node
+import com.personia.dto.Node
 import com.personia.models.Nodes
 import org.jetbrains.exposed.sql.*
 
diff --git a/src/main/kotlin/com/personia/dao/user/UserDaoFacade.kt b/src/main/kotlin/com/personia/dao/user/UserDaoFacade.kt
@@ -1,6 +1,6 @@
 package com.personia.dao.user
 
-import com.personia.models.User
+import com.personia.dto.User
 
 interface UserDaoFacade {
     suspend fun createUser(user: User): User?
diff --git a/src/main/kotlin/com/personia/dao/user/UserDaoImpl.kt b/src/main/kotlin/com/personia/dao/user/UserDaoImpl.kt
@@ -1,7 +1,7 @@
 package com.personia.dao.user
 
 import com.personia.dao.DatabaseFactory.dbQuery
-import com.personia.models.User
+import com.personia.dto.User
 import com.personia.models.Users
 import org.jetbrains.exposed.sql.ResultRow
 import org.jetbrains.exposed.sql.insert
diff --git a/src/main/kotlin/com/personia/dto/Exception.kt b/src/main/kotlin/com/personia/dto/Exception.kt
@@ -0,0 +1,6 @@
+package com.personia.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Exception(val message: String?, val code: Int)
diff --git a/src/main/kotlin/com/personia/dto/Node.kt b/src/main/kotlin/com/personia/dto/Node.kt
@@ -0,0 +1,6 @@
+package com.personia.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Node(val id: Int, val name: String, val supervisor: String)
diff --git a/src/main/kotlin/com/personia/dto/Token.kt b/src/main/kotlin/com/personia/dto/Token.kt
@@ -0,0 +1,6 @@
+package com.personia.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Token(val token: String)
diff --git a/src/main/kotlin/com/personia/dto/User.kt b/src/main/kotlin/com/personia/dto/User.kt
@@ -0,0 +1,6 @@
+package com.personia.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class User(val id: Int? = 0, val username: String, val password: String)
diff --git a/src/main/kotlin/com/personia/models/Node.kt b/src/main/kotlin/com/personia/models/Node.kt
@@ -1,11 +1,7 @@
 package com.personia.models
 
-import kotlinx.serialization.Serializable
 import org.jetbrains.exposed.sql.Table
 
-@Serializable
-data class Node(val id: Int, val name: String, val supervisor: String)
-
 object Nodes : Table() {
     val id = integer("id").autoIncrement()
     val name = varchar("name", 128).uniqueIndex()
diff --git a/src/main/kotlin/com/personia/models/User.kt b/src/main/kotlin/com/personia/models/User.kt
@@ -1,11 +1,7 @@
 package com.personia.models
 
-import kotlinx.serialization.Serializable
 import org.jetbrains.exposed.sql.Table
 
-@Serializable
-data class User(val id: Int? = 0, val username: String, val password: String)
-
 object Users : Table() {
     val id = integer("id").autoIncrement()
     val username = varchar("username", 128).uniqueIndex()
diff --git a/src/main/kotlin/com/personia/plugins/Exception.kt b/src/main/kotlin/com/personia/plugins/Exception.kt
@@ -1,74 +1,59 @@
 package com.personia.plugins
 
-import com.google.gson.Gson
+import com.personia.dto.Exception
 import io.ktor.http.*
 import io.ktor.server.application.*
 import io.ktor.server.plugins.*
 import io.ktor.server.plugins.statuspages.*
 import io.ktor.server.response.*
 import java.sql.SQLException
 
-data class ExceptionTransform(val message: String?, val code: Int)
-
-fun transformException(message: String?, code: Int): String {
-    val gson = Gson()
-    val exception = ExceptionTransform(message, code)
-    return gson.toJson(exception)
-}
-
 fun Application.configureException() {
     install(StatusPages) {
         exception<Throwable> { call, cause ->
 
             val log = call.application.environment.log
-            val applicationJson = ContentType("application", "json")
-
             when (cause) {
                 is AssertionError -> {
                     log.info(cause.message)
-                    call.respondText(
-                        text = transformException(cause.message, HttpStatusCode.BadRequest.value),
-                        status = HttpStatusCode.BadRequest,
-                        contentType = applicationJson
+                    call.response.status(HttpStatusCode.BadRequest)
+                    call.respond(
+                        Exception(cause.message, HttpStatusCode.BadRequest.value)
                     )
                 }
 
                 is SecurityException -> {
                     log.info(cause.message)
-                    call.respondText(
-                        text = transformException("You are a bad guy", HttpStatusCode.Forbidden.value),
-                        status = HttpStatusCode.Forbidden,
-                        contentType = applicationJson
+                    call.response.status(HttpStatusCode.Forbidden)
+                    call.respond(
+                        Exception("You are a bad guy", HttpStatusCode.Forbidden.value),
                     )
                 }
 
                 is SQLException -> {
                     log.info(cause.message)
-                    call.respondText(
-                        text = transformException(
+                    call.response.status(HttpStatusCode.BadRequest)
+                    call.respond(
+                        Exception(
                             "duplicate key value violates unique constraint.",
                             HttpStatusCode.BadRequest.value
                         ),
-                        status = HttpStatusCode.Forbidden,
-                        contentType = applicationJson
                     )
                 }
 
                 is NotFoundException -> {
-                    log.info(cause.message)
-                    call.respondText(
-                        text = transformException(cause.message, HttpStatusCode.NotFound.value),
-                        status = HttpStatusCode.NotFound,
-                        contentType = applicationJson
+                    log.error(cause.message)
+                    call.response.status(HttpStatusCode.NotFound)
+                    call.respond(
+                        Exception(cause.message, HttpStatusCode.NotFound.value),
                     )
                 }
 
-                is Exception -> {
+                is java.lang.Exception -> {
                     log.error(cause.message)
-                    call.respondText(
-                        text = transformException(cause.message, HttpStatusCode.InternalServerError.value),
-                        status = HttpStatusCode.InternalServerError,
-                        contentType = applicationJson
+                    call.response.status(HttpStatusCode.InternalServerError)
+                    call.respond(
+                        Exception(cause.message, HttpStatusCode.InternalServerError.value),
                     )
                 }
             }
diff --git a/src/main/kotlin/com/personia/plugins/Serialization.kt b/src/main/kotlin/com/personia/plugins/Serialization.kt
@@ -1,11 +1,11 @@
 package com.personia.plugins
 
-import io.ktor.serialization.kotlinx.json.*
+import io.ktor.serialization.gson.*
 import io.ktor.server.application.*
 import io.ktor.server.plugins.contentnegotiation.*
 
 fun Application.configureSerialization() {
     install(ContentNegotiation) {
-        json()
+        gson()
     }
 }
diff --git a/src/main/kotlin/com/personia/routes/AuthRoutes.kt b/src/main/kotlin/com/personia/routes/AuthRoutes.kt
@@ -2,7 +2,8 @@ package com.personia.routes
 
 import com.auth0.jwt.JWT
 import com.auth0.jwt.algorithms.Algorithm
-import com.personia.models.User
+import com.personia.dto.Token
+import com.personia.dto.User
 import com.personia.services.UserService
 import io.ktor.http.*
 import io.ktor.server.application.*
@@ -28,7 +29,8 @@ fun Route.authRouting(config: ApplicationConfig, userService: UserService) {
                 .withClaim("username", user.username)
                 .withExpiresAt(Date(System.currentTimeMillis() + expiration))
                 .sign(Algorithm.HMAC256(secret))
-            call.respond(hashMapOf("token" to token))
+            val response = Token(token)
+            call.respond(response)
         } else call.respond(HttpStatusCode.Unauthorized, "username/password is wrong")
     }
 
diff --git a/src/main/kotlin/com/personia/routes/HierarchyRoutes.kt b/src/main/kotlin/com/personia/routes/HierarchyRoutes.kt
@@ -1,6 +1,5 @@
 package com.personia.routes
 
-import com.google.gson.Gson
 import com.personia.services.NodeService
 
 import io.ktor.http.*
@@ -10,9 +9,6 @@ import io.ktor.server.response.*
 import io.ktor.server.routing.*
 
 fun Route.hierarchyRouting(nodeService: NodeService) {
-    val applicationJson = ContentType("application", "json")
-    val gson = Gson()
-
     route("hierarchy") {
         get {
             call.respond(nodeService.getHierarchy())
@@ -38,14 +34,12 @@ fun Route.hierarchyRouting(nodeService: NodeService) {
             val level = call.request.queryParameters["level"]?.toInt() ?: 2
 
             val response = nodeService.retrieveSupervisors(name, level)
-            val json: String = gson.toJson(response)
-            call.respondText(text = json, contentType = applicationJson)
+            call.respond(response)
         }
         post {
             val hierarchy = call.receive<Map<String, String>>()
             val response = nodeService.createHierarchy(hierarchy)
-            val json = gson.toJson(response)
-            call.respondText(text = json, contentType = applicationJson)
+            call.respond(response)
         }
     }
 }
diff --git a/src/main/kotlin/com/personia/services/HierarchyService.kt b/src/main/kotlin/com/personia/services/HierarchyService.kt
@@ -2,43 +2,43 @@ package com.personia.services
 
 import com.personia.dao.node.NodeDaoFacade
 import com.personia.dao.node.nodeDAO
-import com.personia.models.Node
+import com.personia.dto.Node
 import com.personia.utils.Graph
 import io.ktor.server.plugins.*
 
 class NodeService(private val nodeRepository: NodeDaoFacade) {
-    suspend fun getHierarchy(): Map<String, Map<String, Any>> {
+    suspend fun getHierarchy(): HashMap<String, Map<String, Any>> {
         val graph = Graph()
         val hierarchy = nodeRepository.allConnections()
         hierarchy.forEach { (_, node, supervisor) -> graph.connect(supervisor, node) }
         val root = graph.findRoot().root
         val dfs = root?.let { graph.dfs(it) }!!
         val tempMap = graph.transformToNestedMap(dfs)
         val rootValue = tempMap[root] ?: mapOf()
-        return mapOf(root to rootValue)
+        return hashMapOf(root to rootValue)
     }
 
     suspend fun findByName(name: String): Node? = nodeRepository.findByName(name)
 
     @kotlin.jvm.Throws(java.lang.AssertionError::class)
-    suspend fun createHierarchy(hierarchy: Map<String, String>): Map<String?, Map<String, Any>> {
+    suspend fun createHierarchy(hierarchy: Map<String, String>): HashMap<String, Map<String, Any>> {
         val graph = Graph()
         hierarchy.forEach { (node, supervisor) -> graph.connect(supervisor, node) }
         val root = graph.findRoot().root
         val dfs = root?.let { graph.dfs(it) }!!
         hierarchy.forEach { (node, supervisor) -> nodeRepository.upsertNode(node, supervisor) }
         val tempMap = graph.transformToNestedMap(dfs)
         val rootValue = tempMap[root] ?: mapOf()
-        return mapOf(root to rootValue)
+        return hashMapOf(root to rootValue)
     }
 
-    suspend fun retrieveSupervisors(name: String, level: Int): Map<String, Map<String, Any>?> {
+    suspend fun retrieveSupervisors(name: String, level: Int): HashMap<String, Map<String, Any>?> {
         findByName(name) ?: throw NotFoundException("User not found")
         val graph = Graph()
         nodeRepository.allConnections().forEach { graph.connect(it.name, it.supervisor) }
         val visited = graph.dfs(name, level)
         val tmpMap = graph.transformToNestedMap(visited)
-        return mapOf(name to tmpMap[name])
+        return hashMapOf(name to tmpMap[name])
     }
 
 }
diff --git a/src/main/kotlin/com/personia/services/UserService.kt b/src/main/kotlin/com/personia/services/UserService.kt
@@ -2,7 +2,7 @@ package com.personia.services
 
 import com.personia.dao.user.UserDaoFacade
 import com.personia.dao.user.userDAO
-import com.personia.models.User
+import com.personia.dto.User
 import com.personia.utils.Hasher
 import io.ktor.server.plugins.*
 
diff --git a/src/main/kotlin/com/personia/utils/Hasher.kt b/src/main/kotlin/com/personia/utils/Hasher.kt
@@ -1,6 +1,6 @@
 package com.personia.utils
 
-import com.personia.models.User
+import com.personia.dto.User
 import org.mindrot.jbcrypt.BCrypt
 
 object Hasher {
diff --git a/src/test/kotlin/com/personia/integrations/HierarchyTest.kt b/src/test/kotlin/com/personia/integrations/HierarchyTest.kt
diff --git a/src/test/kotlin/com/personia/integrations/UserTest.kt b/src/test/kotlin/com/personia/integrations/UserTest.kt
diff --git a/src/test/kotlin/com/personia/services/NodeServiceTest.kt b/src/test/kotlin/com/personia/services/NodeServiceTest.kt
diff --git a/src/test/kotlin/com/personia/services/UserServiceTest.kt b/src/test/kotlin/com/personia/services/UserServiceTest.kt
