#1707 fix for not defining local variable in stream-iterable mapping (#1708)

processor/src/main/resources/org/mapstruct/ap/internal/model/StreamMappingMethod.ftl

@@ -48,11 +48,11 @@
         </#if>
     }
 
-    <#-- A variable needs to be defined if there are before mappings and this is not exisitingInstanceMapping -->
+    <#-- A variable needs to be defined if there are before or after mappings and this is not exisitingInstanceMapping -->
-    <#assign needVarDefine = beforeMappingReferencesWithMappingTarget?has_content && !existingInstanceMapping />
+    <#assign needVarDefine = (beforeMappingReferencesWithMappingTarget?has_content || afterMappingReferences?has_content) && !existingInstanceMapping />
 
     <#if resultType.arrayType>
-        <#if !existingInstanceMapping && needVarDefine>
+        <#if needVarDefine>
             <#assign needVarDefine = false />
             <#-- We create a null array which later will be directly assigned from the stream-->
             ${resultElementType}[] ${resultName} = null;
@@ -67,7 +67,7 @@
         </#if>
     <#else>
         <#-- Streams are immutable so we can't update them -->
-        <#if !existingInstanceMapping && needVarDefine>
+        <#if needVarDefine>
             <#assign needVarDefine = false />
             <@iterableLocalVarDef/> ${resultName} = Stream.empty();
         </#if>
@@ -180,5 +180,5 @@
     </@compress>
 </#macro>
 <#macro returnLocalVarDefOrUpdate>
-    <#if canReturnImmediatelly><#if returnType.name != "void">return </#if><#elseif !needVarDefine><@iterableLocalVarDef/> ${resultName} = <#else>${resultName} = </#if><#nested />
+    <#if canReturnImmediatelly><#if returnType.name != "void">return </#if><#elseif needVarDefine><@iterableLocalVarDef/> ${resultName} = <#else>${resultName} = </#if><#nested />
 </#macro>

processor/src/test/java/org/mapstruct/ap/test/bugs/_1707/Converter.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1707;
+
+import java.util.Set;
+import java.util.stream.Stream;
+
+import org.mapstruct.AfterMapping;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.MappingTarget;
+
+@Mapper
+public abstract class Converter {
+
+    public abstract Set<Target> convert(Stream<Source> source);
+
+    public abstract Target[] convertArray(Stream<Source> source);
+
+    @Mapping( target = "custom", ignore = true )
+    public abstract Target convert(Source source);
+
+    @AfterMapping
+    public void addCustomValue(@MappingTarget Set<Target> targetList) {
+        targetList.forEach( t -> t.custom = true );
+    }
+
+    @AfterMapping
+    public void addCustomValue(@MappingTarget Target[] targetArray) {
+        for ( Target target : targetArray ) {
+            target.custom = true;
+        }
+    }
+
+    public static final class Source {
+        private String text;
+        private int number;
+
+        public String getText() {
+            return text;
+        }
+
+        public void setText(String text) {
+            this.text = text;
+        }
+
+        public int getNumber() {
+            return number;
+        }
+
+        public void setNumber(int number) {
+            this.number = number;
+        }
+    }
+
+    public static class Target {
+        private String text;
+        private int number;
+        private boolean custom;
+
+        public String getText() {
+            return text;
+        }
+
+        public void setText(String text) {
+            this.text = text;
+        }
+
+        public int getNumber() {
+            return number;
+        }
+
+        public void setNumber(int number) {
+            this.number = number;
+        }
+
+        public boolean isCustom() {
+            return custom;
+        }
+
+        public void setCustom(boolean custom) {
+            this.custom = custom;
+        }
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1707/Issue1707Test.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1707;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+import org.mapstruct.ap.testutil.runner.GeneratedSource;
+
+@RunWith(AnnotationProcessorTestRunner.class)
+@IssueKey("1707")
+@WithClasses({
+    Converter.class
+})
+public class Issue1707Test {
+
+    @Rule
+    public final GeneratedSource generatedSource = new GeneratedSource().addComparisonToFixtureFor(
+        Converter.class
+    );
+
+    @Test
+    public void codeShouldBeGeneratedCorrectly() {
+
+    }
+}

processor/src/test/resources/fixtures/org/mapstruct/ap/test/bugs/_1707/ConverterImpl.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._1707;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import javax.annotation.Generated;
+
+@Generated(
+    value = "org.mapstruct.ap.MappingProcessor",
+    date = "2019-02-10T09:58:11+0100",
+    comments = "version: , compiler: javac, environment: Java 1.8.0_181 (Oracle Corporation)"
+)
+public class ConverterImpl extends Converter {
+
+    @Override
+    public Set<Target> convert(Stream<Source> source) {
+        if ( source == null ) {
+            return null;
+        }
+
+        Set<Target> set = new HashSet<Target>();
+
+        set.addAll( source.map( source1 -> convert( source1 ) )
+            .collect( Collectors.toCollection( HashSet<Target>::new ) )
+        );
+
+        addCustomValue( set );
+
+        return set;
+    }
+
+    @Override
+    public org.mapstruct.ap.test.bugs._1707.Converter.Target[] convertArray(Stream<Source> source) {
+        if ( source == null ) {
+            return null;
+        }
+
+        org.mapstruct.ap.test.bugs._1707.Converter.Target[] targetTmp = null;
+
+        targetTmp = source.map( source1 -> convert( source1 ) )
+        .toArray( Target[]::new );
+
+        addCustomValue( targetTmp );
+
+        return targetTmp;
+    }
+
+    @Override
+    public Target convert(Source source) {
+        if ( source == null ) {
+            return null;
+        }
+
+        Target target = new Target();
+
+        target.setText( source.getText() );
+        target.setNumber( source.getNumber() );
+
+        return target;
+    }
+}