From c3eb04af9561cf842cfb6128b407e048c1778a49 Mon Sep 17 00:00:00 2001
From: stefankoppier <stefan.koppier@outlook.com>
Date: Wed, 26 Jun 2024 09:22:35 +0200
Subject: [PATCH] Improved error message

---
 .../mappie/resolving/classes/ObjectMappingBodyCollector.kt | 3 ++-
 .../tech/mappie/resolving/classes/ObjectMappingSource.kt   | 1 +
 .../kotlin/tech/mappie/validation/MappingValidation.kt     | 7 ++++++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingBodyCollector.kt b/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingBodyCollector.kt
index 65fe4c68..1505a7db 100644
--- a/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingBodyCollector.kt
+++ b/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingBodyCollector.kt
@@ -80,7 +80,8 @@ private class ObjectBodyStatementCollector(
                 target to ExpressionSource(
                     dispatchReceiverSymbol,
                     source,
-                    (source.type as IrSimpleType).arguments[1].typeOrFail
+                    (source.type as IrSimpleType).arguments[1].typeOrFail,
+                    expression,
                 )
             }
             IDENTIFIER_TRANFORM -> {
diff --git a/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingSource.kt b/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingSource.kt
index a4eb1627..5fd9dec3 100644
--- a/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingSource.kt
+++ b/compiler-plugin/src/main/kotlin/tech/mappie/resolving/classes/ObjectMappingSource.kt
@@ -36,6 +36,7 @@ data class ExpressionSource(
     val extensionReceiverSymbol: IrValueSymbol,
     val expression: IrFunctionExpression,
     val type: IrType,
+    val origin: IrExpression?,
 ) : ObjectMappingSource {
     override fun resolveType() = type
 }
diff --git a/compiler-plugin/src/main/kotlin/tech/mappie/validation/MappingValidation.kt b/compiler-plugin/src/main/kotlin/tech/mappie/validation/MappingValidation.kt
index 5f7b4cb4..2ac46bf3 100644
--- a/compiler-plugin/src/main/kotlin/tech/mappie/validation/MappingValidation.kt
+++ b/compiler-plugin/src/main/kotlin/tech/mappie/validation/MappingValidation.kt
@@ -11,6 +11,7 @@ import tech.mappie.util.location
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageLocation
 import org.jetbrains.kotlin.ir.IrFileEntry
 import org.jetbrains.kotlin.ir.types.getClass
+import tech.mappie.resolving.classes.ExpressionSource
 
 data class Problem(
     val description: String,
@@ -56,7 +57,11 @@ interface MappingValidation {
                         .filter { (target, sources) -> !target.type.isAssignableFrom(sources.single().resolveType()) }
                         .map { (target, sources) -> Problem.error(
                             "Target ${mapping.targetType.getClass()!!.name.asString()}.${target.name.asString()} has type ${target.type.pretty()} which cannot be assigned from type ${sources.single().resolveType().pretty()}",
-                            (sources.single() as? PropertySource)?.origin?.let { location(file, it) }
+                            when (val source = sources.single()) {
+                                is PropertySource -> source.origin?.let { location(file, it) }
+                                is ExpressionSource -> source.origin?.let { location(file, it) }
+                                else -> null
+                            }
                         ) }
                 )