#2897 Always import types defined in Mapper#imports

processor/src/main/java/org/mapstruct/ap/internal/model/common/TypeFactory.java

@@ -193,7 +193,24 @@ public class TypeFactory {
         return getType( mirror, false );
     }
 
+    /**
+     * Return a type that is always going to be imported.
+     * This is useful when using it in {@code Mapper#imports}
+     * for types that should be used in expressions.
+     *
+     * @param mirror the type mirror for which we need a type
+     *
+     * @return the type
+     */
+    public Type getAlwaysImportedType(TypeMirror mirror) {
+        return getType( mirror, false, true );
+    }
+
     private Type getType(TypeMirror mirror, boolean isLiteral) {
+        return getType( mirror, isLiteral, null );
+    }
+
+    private Type getType(TypeMirror mirror, boolean isLiteral, Boolean alwaysImport) {
         if ( !canBeProcessed( mirror ) ) {
             throw new TypeHierarchyErroneousException( mirror );
         }
@@ -212,7 +229,7 @@ public class TypeFactory {
         String qualifiedName;
         TypeElement typeElement;
         Type componentType;
-        Boolean toBeImported = null;
+        Boolean toBeImported = alwaysImport;
 
         if ( mirror.getKind() == TypeKind.DECLARED ) {
             DeclaredType declaredType = (DeclaredType) mirror;

processor/src/main/java/org/mapstruct/ap/internal/processor/MapperCreationProcessor.java

@@ -307,7 +307,7 @@ public class MapperCreationProcessor implements ModelElementProcessor<List<Sourc
 
 
         for ( TypeMirror extraImport : mapperOptions.imports() ) {
-            Type type = typeFactory.getType( extraImport );
+            Type type = typeFactory.getAlwaysImportedType( extraImport );
             extraImports.add( type );
         }
 

processor/src/test/java/org/mapstruct/ap/test/bugs/_2897/Issue2897Mapper.java

@@ -0,0 +1,23 @@
+/*
+ * 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._2897;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.ap.test.bugs._2897.util.Util;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper(imports = Util.Factory.class)
+public interface Issue2897Mapper {
+
+    Issue2897Mapper INSTANCE = Mappers.getMapper( Issue2897Mapper.class );
+
+    @Mapping( target = "value", expression = "java(Factory.parse( source ))")
+    Target map(Source source);
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2897/Issue2897Test.java

@@ -0,0 +1,33 @@
+/*
+ * 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._2897;
+
+import org.mapstruct.ap.test.bugs._2897.util.Util;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.ProcessorTest;
+import org.mapstruct.ap.testutil.WithClasses;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Filip Hrisafov
+ */
+@IssueKey("2897")
+@WithClasses({
+    Util.class,
+    Issue2897Mapper.class,
+    Source.class,
+    Target.class,
+})
+class Issue2897Test {
+
+    @ProcessorTest
+    void shouldImportNestedClassInMapperImports() {
+        Target target = Issue2897Mapper.INSTANCE.map( new Source( "test" ) );
+
+        assertThat( target.getValue() ).isEqualTo( "parsed(test)" );
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2897/Source.java

@@ -0,0 +1,22 @@
+/*
+ * 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._2897;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Source {
+
+    private final String value;
+
+    public Source(String value) {
+        this.value = value;
+    }
+
+    public String getValue() {
+        return value;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2897/Target.java

@@ -0,0 +1,22 @@
+/*
+ * 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._2897;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Target {
+
+    private final String value;
+
+    public Target(String value) {
+        this.value = value;
+    }
+
+    public String getValue() {
+        return value;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2897/util/Util.java

@@ -0,0 +1,21 @@
+/*
+ * 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._2897.util;
+
+import org.mapstruct.ap.test.bugs._2897.Source;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class Util {
+
+    public static class Factory {
+
+        public static String parse(Source source) {
+            return source == null ? null : "parsed(" + source.getValue() + ")";
+        }
+    }
+}