From 06c416043ca361e075e4bb19e09edf539010c499 Mon Sep 17 00:00:00 2001
From: Bas Claessen <35045227+basclaessen@users.noreply.github.com>
Date: Sat, 14 Aug 2021 09:06:54 +0200
Subject: [PATCH] #2515 add ambiguous constructors to ambiguous constructor
 error message

---
 .../mapstruct/ap/internal/model/BeanMappingMethod.java | 10 +++++++++-
 .../java/org/mapstruct/ap/internal/util/Message.java   |  2 +-
 .../erroneous/ErroneousConstructorTest.java            |  6 ++++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
index 4ebcd9f5e..36dae0ba5 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
@@ -26,6 +26,7 @@ import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
+import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.util.ElementFilter;
@@ -699,7 +700,14 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                     method.getExecutable(),
                     GENERAL_AMBIGUOUS_CONSTRUCTORS,
                     type,
-                    Strings.join( constructors, ", " )
+                    constructors.stream()
+                        .map( ExecutableElement::getParameters )
+                        .map( ps -> ps.stream()
+                            .map( VariableElement::asType )
+                            .map( String::valueOf )
+                            .collect( Collectors.joining( ", ", type.getName() + "(", ")" ) )
+                        )
+                        .collect( Collectors.joining( ", " ) )
                 );
                 return null;
             }
diff --git a/processor/src/main/java/org/mapstruct/ap/internal/util/Message.java b/processor/src/main/java/org/mapstruct/ap/internal/util/Message.java
index f2226ab22..8d328d479 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/util/Message.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/util/Message.java
@@ -125,7 +125,7 @@ public enum Message {
     GENERAL_AMBIGUOUS_MAPPING_METHOD( "Ambiguous mapping methods found for mapping %s to %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
     GENERAL_AMBIGUOUS_FACTORY_METHOD( "Ambiguous factory methods found for creating %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
     GENERAL_AMBIGUOUS_PRESENCE_CHECK_METHOD( "Ambiguous presence check methods found for checking %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
-    GENERAL_AMBIGUOUS_CONSTRUCTORS( "Ambiguous constructors found for creating %s. Either declare parameterless constructor or annotate the default constructor with an annotation named @Default." ),
+    GENERAL_AMBIGUOUS_CONSTRUCTORS( "Ambiguous constructors found for creating %s: %s. Either declare parameterless constructor or annotate the default constructor with an annotation named @Default." ),
     GENERAL_CONSTRUCTOR_PROPERTIES_NOT_MATCHING_PARAMETERS( "Incorrect @ConstructorProperties for %s. The size of the @ConstructorProperties does not match the number of constructor parameters" ),
     GENERAL_UNSUPPORTED_DATE_FORMAT_CHECK( "No dateFormat check is supported for types %s, %s" ),
     GENERAL_VALID_DATE( "Given date format \"%s\" is valid.", Diagnostic.Kind.NOTE ),
diff --git a/processor/src/test/java/org/mapstruct/ap/test/constructor/erroneous/ErroneousConstructorTest.java b/processor/src/test/java/org/mapstruct/ap/test/constructor/erroneous/ErroneousConstructorTest.java
index 2799e1084..5a8483f23 100644
--- a/processor/src/test/java/org/mapstruct/ap/test/constructor/erroneous/ErroneousConstructorTest.java
+++ b/processor/src/test/java/org/mapstruct/ap/test/constructor/erroneous/ErroneousConstructorTest.java
@@ -29,8 +29,10 @@ public class ErroneousConstructorTest {
             kind = javax.tools.Diagnostic.Kind.ERROR,
             line = 17,
             message = "Ambiguous constructors found for creating org.mapstruct.ap.test.constructor.erroneous" +
-                ".ErroneousAmbiguousConstructorsMapper.PersonWithMultipleConstructors. Either declare parameterless " +
-                "constructor or annotate the default constructor with an annotation named @Default."
+                ".ErroneousAmbiguousConstructorsMapper.PersonWithMultipleConstructors: " +
+                "PersonWithMultipleConstructors(java.lang.String), " +
+                "PersonWithMultipleConstructors(java.lang.String, int). Either declare parameterless constructor " +
+                "or annotate the default constructor with an annotation named @Default."
         )
     })
     public void shouldUseMultipleConstructors() {