Fix missing types for parameter and value mapping lookups in newer IntelliJ versions

Add IntelliJ 2020.2 and 2020.3 to the build matrix

Fixes #71

Author: filiphr

.github/workflows/main.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ideaVersion: [2019.1, 2019.2, 2019.3, 2020.1, LATEST-EAP-SNAPSHOT]
+        ideaVersion: [2019.1, 2019.2, 2019.3, 2020.1, 2020.2, 2020.3, LATEST-EAP-SNAPSHOT]
     name: 'IDEA ${{ matrix.ideaVersion }}'
     env:
       IDEA_VERSION: ${{ matrix.ideaVersion }}

src/main/java/org/mapstruct/intellij/codeinsight/references/MapstructSourceReference.java

@@ -106,7 +106,9 @@ Object[] getVariantsInternal(@NotNull PsiMethod mappingMethod) {
             return parameterType == null ? LookupElement.EMPTY_ARRAY : getVariantsInternal( parameterType );
         }
 
-        return sourceParameters;
+        return Stream.of( sourceParameters )
+            .map( MapstructUtil::asLookup )
+            .toArray( LookupElement[]::new );
     }
 
     @Nullable

src/main/java/org/mapstruct/intellij/codeinsight/references/ValueMappingSourceReference.java

@@ -17,6 +17,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import static org.mapstruct.intellij.util.MapstructUtil.asLookup;
 import static org.mapstruct.intellij.util.SourceUtils.getParameterClass;
 
 /**
@@ -60,7 +61,8 @@ Object[] getVariantsInternal(@NotNull PsiMethod mappingMethod) {
 
         return Stream.of( sourceClass.getFields() )
             .filter( psiField -> psiField instanceof PsiEnumConstant )
-            .toArray( PsiField[]::new );
+            .map( psiEnumConstant -> asLookup( (PsiEnumConstant) psiEnumConstant ) )
+            .toArray( LookupElement[]::new );
     }
 
     /**

src/main/java/org/mapstruct/intellij/codeinsight/references/ValueMappingTargetReference.java

@@ -18,6 +18,8 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import static org.mapstruct.intellij.util.MapstructUtil.asLookup;
+
 /**
  * Reference for {@link org.mapstruct.ValueMapping#target()}.
  *
@@ -59,7 +61,8 @@ Object[] getVariantsInternal(@NotNull PsiMethod mappingMethod) {
 
         return Stream.of( targetClass.getFields() )
             .filter( psiField -> psiField instanceof PsiEnumConstant )
-            .toArray( PsiField[]::new );
+            .map( psiEnumConstant -> asLookup( (PsiEnumConstant) psiEnumConstant ) )
+            .toArray( LookupElement[]::new );
     }
 
     /**

src/main/java/org/mapstruct/intellij/util/MapstructUtil.java

@@ -12,6 +12,7 @@
 import java.util.Map;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import javax.swing.Icon;
 
 import com.intellij.codeInsight.AnnotationUtil;
 import com.intellij.codeInsight.lookup.LookupElement;
@@ -21,11 +22,13 @@
 import com.intellij.openapi.roots.ProjectRootManager;
 import com.intellij.openapi.util.Pair;
 import com.intellij.psi.CommonClassNames;
+import com.intellij.psi.EmptySubstitutor;
 import com.intellij.psi.JavaPsiFacade;
 import com.intellij.psi.PsiArrayType;
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiClassType;
 import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiEnumConstant;
 import com.intellij.psi.PsiField;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiMethod;
@@ -109,7 +112,8 @@ public static LookupElement[] asLookup(Map<String, Pair<? extends PsiElement, Ps
                 lookupElements[index++] = asLookup(
                     propertyName,
                     pair,
-                    typeMapper
+                    typeMapper,
+                    PlatformIcons.VARIABLE_ICON
                 );
             }
             return lookupElements;
@@ -120,13 +124,29 @@ public static LookupElement[] asLookup(Map<String, Pair<? extends PsiElement, Ps
 
     }
 
+    public static LookupElement asLookup(PsiParameter parameter) {
+        return asLookup( parameter.getName(), parameter, PsiParameter::getType, PlatformIcons.PARAMETER_ICON );
+    }
+
+    public static LookupElement asLookup(PsiEnumConstant enumConstant) {
+        return asLookup( enumConstant.getName(), enumConstant, PsiField::getType, PlatformIcons.FIELD_ICON );
+    }
+
+    public static <T extends PsiElement> LookupElement asLookup(String propertyName, @NotNull T psiElement,
+                                                                Function<T, PsiType> typeMapper, Icon icon) {
+        //noinspection unchecked
+        return asLookup( propertyName, Pair.pair( psiElement, EmptySubstitutor.getInstance() ),
+            (Function<PsiElement, PsiType>) typeMapper, icon
+        );
+    }
+
     public static LookupElement asLookup(String propertyName, @NotNull Pair<? extends PsiElement, PsiSubstitutor> pair,
-        Function<PsiElement, PsiType> typeMapper) {
+        Function<PsiElement, PsiType> typeMapper, Icon icon) {
         PsiElement member = pair.getFirst();
         PsiSubstitutor substitutor = pair.getSecond();
 
         LookupElementBuilder builder = LookupElementBuilder.create( member, propertyName )
-            .withIcon( PlatformIcons.VARIABLE_ICON )
+            .withIcon( icon )
             .withPresentableText( propertyName )
             .withTailText( formatTailText( member, substitutor ) );
         final PsiType type = typeMapper.apply( member );
@@ -138,20 +158,23 @@ public static LookupElement asLookup(String propertyName, @NotNull Pair<? extend
     }
 
     private static String formatTailText(PsiElement member, PsiSubstitutor substitutor) {
+        String tailText;
         if ( member instanceof PsiMethod ) {
-            return PsiFormatUtil.formatMethod(
+            tailText = PsiFormatUtil.formatMethod(
                 (PsiMethod) member,
                 substitutor,
                 0,
                 PsiFormatUtilBase.SHOW_NAME | PsiFormatUtilBase.SHOW_TYPE
             );
         }
         else if ( member instanceof PsiVariable ) {
-            return PsiFormatUtil.formatVariable( (PsiVariable) member, 0, substitutor );
+            tailText = PsiFormatUtil.formatVariable( (PsiVariable) member, 0, substitutor );
         }
         else {
-            return "";
+            tailText = "";
         }
+
+        return !tailText.isEmpty() ? tailText : null;
     }
 
     public static boolean isPublic(@NotNull PsiMethod method) {

src/test/java/org/mapstruct/intellij/testutil/TestUtils.java

@@ -24,7 +24,7 @@ public static LookupElementPresentation createField(String lookupString, String
     }
 
     public static LookupElementPresentation createVariable(String lookupString, String typeText) {
-        return create( lookupString, typeText, PlatformIcons.VARIABLE_ICON, "" );
+        return create( lookupString, typeText, PlatformIcons.VARIABLE_ICON, null );
     }
 
     public static LookupElementPresentation createParameter(String lookupString, String typeText) {