Consolidate exception message and improve it (#2068)

Fixes #2066

Author: qwwdfsad

core/commonMain/src/kotlinx/serialization/internal/Platform.common.kt

@@ -21,7 +21,7 @@ internal object InternalHexConverter {
         while (i < len) {
             val h = hexToInt(s[i])
             val l = hexToInt(s[i + 1])
-            require(!(h == -1 || l == -1)) { "Invalid hex chars: ${s[i]}${s[i+1]}" }
+            require(!(h == -1 || l == -1)) { "Invalid hex chars: ${s[i]}${s[i + 1]}" }
 
             bytes[i / 2] = ((h shl 4) + l).toByte()
             i += 2
@@ -85,25 +85,29 @@ internal inline fun <T> SerializationStrategy<*>.cast(): SerializationStrategy<T
 
 @Suppress("UNCHECKED_CAST", "NOTHING_TO_INLINE")
 @PublishedApi
-internal inline fun <T> DeserializationStrategy<*>.cast(): DeserializationStrategy<T> = this as DeserializationStrategy<T>
+internal inline fun <T> DeserializationStrategy<*>.cast(): DeserializationStrategy<T> =
+    this as DeserializationStrategy<T>
 
 internal fun KClass<*>.serializerNotRegistered(): Nothing {
-    throw SerializationException(
-        "Serializer for class '${simpleName}' is not found.\n" +
-            "Mark the class as @Serializable or provide the serializer explicitly."
-    )
+    throw SerializationException(notRegisteredMessage())
 }
 
+internal fun KClass<*>.notRegisteredMessage(): String = "Serializer for class '${simpleName}' is not found.\n" +
+        "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
+
 internal expect fun KClass<*>.platformSpecificSerializerNotRegistered(): Nothing
 
 @Suppress("UNCHECKED_CAST")
 internal fun KType.kclass() = when (val t = classifier) {
     is KClass<*> -> t
     is KTypeParameter -> {
-        error("Captured type paramerer $t from generic non-reified function. " +
-                "Such functionality cannot be supported as $t is erased, either specify serializer explicitly or make " +
-                "calling function inline with reified $t")
+        error(
+            "Captured type parameter $t from generic non-reified function. " +
+                    "Such functionality cannot be supported as $t is erased, either specify serializer explicitly or make " +
+                    "calling function inline with reified $t"
+        )
     }
+
     else -> error("Only KClass supported as classifier, got $t")
 } as KClass<Any>
 
@@ -144,16 +148,6 @@ internal expect fun <T> createParametrizedCache(factory: (KClass<Any>, List<KTyp
 
 internal expect fun <T : Any, E : T?> ArrayList<E>.toNativeArrayImpl(eClass: KClass<T>): Array<E>
 
-/**
- * Checks whether the receiver is an instance of a given kclass.
- *
- * This check is a replacement for [KClass.isInstance] because on JVM it requires kotlin-reflect.jar in classpath (see KT-14720).
- *
- * On JS and Native, this function delegates to aforementioned [KClass.isInstance] since it is supported there out-of-the-box;
- * on JVM, it falls back to `java.lang.Class.isInstance`, which causes difference when applied to function types with big arity.
- */
-internal expect fun Any.isInstanceOf(kclass: KClass<*>): Boolean
-
 internal inline fun <T, K> Iterable<T>.elementsHashCodeBy(selector: (T) -> K): Int {
     return fold(1) { hash, element -> 31 * hash + selector(element).hashCode() }
 }

core/commonMain/src/kotlinx/serialization/modules/SerializersModule.kt

@@ -153,7 +153,7 @@ internal class SerialModuleImpl(
 ) : SerializersModule() {
 
     override fun <T : Any> getPolymorphic(baseClass: KClass<in T>, value: T): SerializationStrategy<T>? {
-        if (!value.isInstanceOf(baseClass)) return null
+        if (!baseClass.isInstance(value)) return null
         // Registered
         val registered = polyBase2Serializers[baseClass]?.get(value::class) as? SerializationStrategy<T>
         if (registered != null) return registered

core/jsMain/src/kotlinx/serialization/internal/Platform.kt

@@ -38,12 +38,9 @@ internal actual fun <T> createParametrizedCache(factory: (KClass<Any>, List<KTyp
 
 internal actual fun <T : Any, E : T?> ArrayList<E>.toNativeArrayImpl(eClass: KClass<T>): Array<E> = toTypedArray()
 
-internal actual fun Any.isInstanceOf(kclass: KClass<*>): Boolean = kclass.isInstance(this)
-
 internal actual fun KClass<*>.platformSpecificSerializerNotRegistered(): Nothing {
     throw SerializationException(
-        "Serializer for class '${simpleName}' is not found.\n" +
-                "Mark the class as @Serializable or provide the serializer explicitly.\n" +
+        "${notRegisteredMessage()}\n" +
                 "On Kotlin/JS explicitly declared serializer should be used for interfaces and enums without @Serializable annotation"
     )
 }

core/jvmMain/src/kotlinx/serialization/SerializersJvm.kt

@@ -73,8 +73,8 @@ public fun serializerOrNull(type: Type): KSerializer<Any>? = EmptySerializersMod
  * @throws IllegalArgumentException if an unsupported subclass of [Type] is provided.
  */
 public fun SerializersModule.serializer(type: Type): KSerializer<Any> =
-    serializerByJavaTypeImpl(type, failOnMissingTypeArgSerializer = true) ?: type.prettyClass()
-        .serializerNotRegistered()
+    serializerByJavaTypeImpl(type, failOnMissingTypeArgSerializer = true)
+        ?: type.prettyClass().serializerNotRegistered()
 
 /**
  * Retrieves a serializer for the given [type] using

core/jvmMain/src/kotlinx/serialization/internal/Platform.kt

@@ -18,7 +18,6 @@ internal actual inline fun BooleanArray.getChecked(index: Int): Boolean {
     return get(index)
 }
 
-@Suppress("UNCHECKED_CAST")
 internal actual fun <T : Any> KClass<T>.compiledSerializerImpl(): KSerializer<T>? =
     this.constructSerializerForGivenTypeArgs()
 
@@ -29,10 +28,7 @@ internal actual fun <T : Any, E : T?> ArrayList<E>.toNativeArrayImpl(eClass: KCl
 internal actual fun KClass<*>.platformSpecificSerializerNotRegistered(): Nothing = serializerNotRegistered()
 
 internal fun Class<*>.serializerNotRegistered(): Nothing {
-    throw SerializationException(
-        "Serializer for class '${simpleName}' is not found.\n" +
-                "Mark the class as @Serializable or provide the serializer explicitly."
-    )
+    throw SerializationException(this.kotlin.notRegisteredMessage())
 }
 
 internal actual fun <T : Any> KClass<T>.constructSerializerForGivenTypeArgs(vararg args: KSerializer<Any?>): KSerializer<T>? {
@@ -149,18 +145,4 @@ private fun <T : Any> Class<T>.findObjectSerializer(): KSerializer<T>? {
     return result as? KSerializer<T>
 }
 
-/**
- * Checks if an [this@isInstanceOf] is an instance of a given [kclass].
- *
- * This check is a replacement for [KClass.isInstance] because
- * on JVM it requires kotlin-reflect.jar in classpath
- * (see https://youtrack.jetbrains.com/issue/KT-14720).
- *
- * On JS and Native, this function delegates to aforementioned
- * [KClass.isInstance] since it is supported there out-of-the box;
- * on JVM, it falls back to java.lang.Class.isInstance, which causes
- * difference when applied to function types with big arity.
- */
-internal actual fun Any.isInstanceOf(kclass: KClass<*>): Boolean = kclass.javaObjectType.isInstance(this)
-
 internal actual fun isReferenceArray(rootClass: KClass<Any>): Boolean = rootClass.java.isArray

core/nativeMain/src/kotlinx/serialization/internal/Platform.kt

@@ -19,8 +19,7 @@ internal actual inline fun BooleanArray.getChecked(index: Int): Boolean {
 
 internal actual fun KClass<*>.platformSpecificSerializerNotRegistered(): Nothing {
     throw SerializationException(
-        "Serializer for class '${simpleName}' is not found.\n" +
-                "Mark the class as @Serializable or provide the serializer explicitly.\n" +
+        "${notRegisteredMessage()}\n" +
                 "On Kotlin/Native explicitly declared serializer should be used for interfaces and enums without @Serializable annotation"
     )
 }
@@ -37,11 +36,7 @@ internal actual fun <T : Any> KClass<T>.constructSerializerForGivenTypeArgs(vara
         else -> null
     }
 
-@Suppress(
-    "UNCHECKED_CAST",
-    "DEPRECATION_ERROR"
-)
-@OptIn(ExperimentalAssociatedObjects::class)
+@Suppress("DEPRECATION_ERROR")
 internal actual fun <T : Any> KClass<T>.compiledSerializerImpl(): KSerializer<T>? =
     this.constructSerializerForGivenTypeArgs()
 
@@ -66,13 +61,11 @@ internal actual fun <T : Any, E : T?> ArrayList<E>.toNativeArrayImpl(eClass: KCl
     val result = arrayOfAnyNulls<E>(size)
     var index = 0
     for (element in this) result[index++] = element
-    @Suppress("UNCHECKED_CAST", "USELESS_CAST")
+    @Suppress("USELESS_CAST")
     return result as Array<E>
 }
 
 @Suppress("UNCHECKED_CAST")
 private fun <T> arrayOfAnyNulls(size: Int): Array<T> = arrayOfNulls<Any>(size) as Array<T>
 
-internal actual fun Any.isInstanceOf(kclass: KClass<*>): Boolean = kclass.isInstance(this)
-
 internal actual fun isReferenceArray(rootClass: KClass<Any>): Boolean = rootClass == Array::class

docs/basic-serialization.md

@@ -79,7 +79,7 @@ When we run this code we get the exception.
 
 ```text
 Exception in thread "main" kotlinx.serialization.SerializationException: Serializer for class 'Project' is not found.
-Mark the class as @Serializable or provide the serializer explicitly.
+Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied.
 ```
 
 <!--- TEST LINES_START -->

docs/polymorphism.md

@@ -92,7 +92,7 @@ We get an error, because the `OwnedProject` class is not serializable.
 
 ```text
 Exception in thread "main" kotlinx.serialization.SerializationException: Serializer for class 'OwnedProject' is not found.
-Mark the class as @Serializable or provide the serializer explicitly.
+Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied.
 ```                                                                       
 
 <!--- TEST LINES_START -->
@@ -495,7 +495,7 @@ We get the exception.
 
 ```text
 Exception in thread "main" kotlinx.serialization.SerializationException: Serializer for class 'Any' is not found.
-Mark the class as @Serializable or provide the serializer explicitly.
+Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied.
 ```
 
 <!--- TEST LINES_START -->
@@ -543,7 +543,7 @@ However, the `Any` is a class and it is not serializable:
 
 ```text 
 Exception in thread "main" kotlinx.serialization.SerializationException: Serializer for class 'Any' is not found.
-Mark the class as @Serializable or provide the serializer explicitly.
+Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied.
 ```
 
 <!--- TEST LINES_START -->

docs/serializers.md

@@ -973,7 +973,7 @@ functions. Without it we'll get a "Serializer for class 'Date' is not found" exc
 
 <!--- TEST LINES_START 
 Exception in thread "main" kotlinx.serialization.SerializationException: Serializer for class 'Date' is not found.
-Mark the class as @Serializable or provide the serializer explicitly.
+Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied.
 -->
 
 <!--- INCLUDE

guide/test/BasicSerializationTest.kt

@@ -9,7 +9,7 @@ class BasicSerializationTest {
     fun testExampleBasic01() {
         captureOutput("ExampleBasic01") { example.exampleBasic01.main() }.verifyOutputLinesStart(
             "Exception in thread \"main\" kotlinx.serialization.SerializationException: Serializer for class 'Project' is not found.",
-            "Mark the class as @Serializable or provide the serializer explicitly."
+            "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
         )
     }
 

guide/test/PolymorphismTest.kt

@@ -16,7 +16,7 @@ class PolymorphismTest {
     fun testExamplePoly02() {
         captureOutput("ExamplePoly02") { example.examplePoly02.main() }.verifyOutputLinesStart(
             "Exception in thread \"main\" kotlinx.serialization.SerializationException: Serializer for class 'OwnedProject' is not found.",
-            "Mark the class as @Serializable or provide the serializer explicitly."
+            "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
         )
     }
 
@@ -88,15 +88,15 @@ class PolymorphismTest {
     fun testExamplePoly12() {
         captureOutput("ExamplePoly12") { example.examplePoly12.main() }.verifyOutputLinesStart(
             "Exception in thread \"main\" kotlinx.serialization.SerializationException: Serializer for class 'Any' is not found.",
-            "Mark the class as @Serializable or provide the serializer explicitly."
+            "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
         )
     }
 
     @Test
     fun testExamplePoly13() {
         captureOutput("ExamplePoly13") { example.examplePoly13.main() }.verifyOutputLinesStart(
             "Exception in thread \"main\" kotlinx.serialization.SerializationException: Serializer for class 'Any' is not found.",
-            "Mark the class as @Serializable or provide the serializer explicitly."
+            "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
         )
     }
 

guide/test/SerializersTest.kt

@@ -136,7 +136,7 @@ class SerializersTest {
     fun testExampleSerializer19() {
         captureOutput("ExampleSerializer19") { example.exampleSerializer19.main() }.verifyOutputLinesStart(
             "Exception in thread \"main\" kotlinx.serialization.SerializationException: Serializer for class 'Date' is not found.",
-            "Mark the class as @Serializable or provide the serializer explicitly."
+            "Please ensure that class is marked as '@Serializable' and that the serialization compiler plugin is applied."
         )
     }