Refactor presence checks to object in order to simplify the conditional mapping

processor/src/main/java/org/mapstruct/ap/internal/model/MethodReference.java

@@ -19,6 +19,7 @@ import org.mapstruct.ap.internal.model.common.ConversionContext;
 import org.mapstruct.ap.internal.model.common.ModelElement;
 import org.mapstruct.ap.internal.model.common.Parameter;
 import org.mapstruct.ap.internal.model.common.ParameterBinding;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.common.Type;
 import org.mapstruct.ap.internal.model.source.Method;
 import org.mapstruct.ap.internal.model.source.builtin.BuiltInMethod;
@@ -197,7 +198,7 @@ public class MethodReference extends ModelElement implements Assignment {
     }
 
     @Override
-    public String getSourcePresenceCheckerReference() {
+    public PresenceCheck getSourcePresenceCheckerReference() {
         return assignment.getSourcePresenceCheckerReference();
     }
 

processor/src/main/java/org/mapstruct/ap/internal/model/NestedPropertyMappingMethod.java

@@ -11,8 +11,10 @@ import java.util.Objects;
 import java.util.Set;
 
 import org.mapstruct.ap.internal.model.common.Parameter;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.common.Type;
 import org.mapstruct.ap.internal.model.beanmapping.PropertyEntry;
+import org.mapstruct.ap.internal.model.presence.SourceReferenceMethodPresenceCheck;
 import org.mapstruct.ap.internal.util.Strings;
 import org.mapstruct.ap.internal.util.ValueProvider;
 
@@ -52,17 +54,27 @@ public class NestedPropertyMappingMethod extends MappingMethod {
 
         public NestedPropertyMappingMethod build() {
             List<String> existingVariableNames = new ArrayList<>();
+            Parameter sourceParameter = null;
             for ( Parameter parameter : method.getSourceParameters() ) {
                 existingVariableNames.add( parameter.getName() );
+                if ( sourceParameter == null && !parameter.isMappingTarget() && !parameter.isMappingContext() ) {
+                    sourceParameter = parameter;
+                }
             }
             final List<Type> thrownTypes = new ArrayList<>();
             List<SafePropertyEntry> safePropertyEntries = new ArrayList<>();
+            if ( sourceParameter == null ) {
+                throw new IllegalStateException( "Method " + method + " has no source parameter." );
+            }
+
+            String previousPropertyName = sourceParameter.getName();
             for ( PropertyEntry propertyEntry : propertyEntries ) {
                 String safeName = Strings.getSafeVariableName( propertyEntry.getName(), existingVariableNames );
-                safePropertyEntries.add( new SafePropertyEntry( propertyEntry, safeName ) );
+                safePropertyEntries.add( new SafePropertyEntry( propertyEntry, safeName, previousPropertyName ) );
                 existingVariableNames.add( safeName );
                 thrownTypes.addAll( ctx.getTypeFactory().getThrownTypes(
                         propertyEntry.getReadAccessor() ) );
+                previousPropertyName = safeName;
             }
             method.addThrownTypes( thrownTypes );
             return new NestedPropertyMappingMethod( method, safePropertyEntries );
@@ -92,6 +104,9 @@ public class NestedPropertyMappingMethod extends MappingMethod {
         Set<Type> types = super.getImportTypes();
         for ( SafePropertyEntry propertyEntry : safePropertyEntries) {
             types.add( propertyEntry.getType() );
+            if ( propertyEntry.getPresenceChecker() != null ) {
+                types.addAll( propertyEntry.getPresenceChecker().getImportTypes() );
+            }
         }
         return types;
     }
@@ -143,18 +158,23 @@ public class NestedPropertyMappingMethod extends MappingMethod {
 
         private final String safeName;
         private final String readAccessorName;
-        private final String presenceCheckerName;
+        private final PresenceCheck presenceChecker;
+        private final String previousPropertyName;
         private final Type type;
 
-        public SafePropertyEntry(PropertyEntry entry, String safeName) {
+        public SafePropertyEntry(PropertyEntry entry, String safeName, String previousPropertyName) {
             this.safeName = safeName;
             this.readAccessorName = ValueProvider.of( entry.getReadAccessor() ).getValue();
             if ( entry.getPresenceChecker() != null ) {
-                this.presenceCheckerName = entry.getPresenceChecker().getSimpleName();
+                this.presenceChecker = new SourceReferenceMethodPresenceCheck(
+                    previousPropertyName,
+                    entry.getPresenceChecker().getSimpleName()
+                );
             }
             else {
-                this.presenceCheckerName = null;
+                this.presenceChecker = null;
             }
+            this.previousPropertyName = previousPropertyName;
             this.type = entry.getType();
         }
 
@@ -166,8 +186,12 @@ public class NestedPropertyMappingMethod extends MappingMethod {
             return readAccessorName;
         }
 
-        public String getPresenceCheckerName() {
+        public PresenceCheck getPresenceChecker() {
-            return presenceCheckerName;
+            return presenceChecker;
+        }
+
+        public String getPreviousPropertyName() {
+            return previousPropertyName;
         }
 
         public Type getType() {
@@ -189,7 +213,11 @@ public class NestedPropertyMappingMethod extends MappingMethod {
                 return false;
             }
 
-            if ( !Objects.equals( presenceCheckerName, that.presenceCheckerName ) ) {
+            if ( !Objects.equals( presenceChecker, that.presenceChecker ) ) {
+                return false;
+            }
+
+            if ( !Objects.equals( previousPropertyName, that.previousPropertyName ) ) {
                 return false;
             }
 
@@ -203,7 +231,7 @@ public class NestedPropertyMappingMethod extends MappingMethod {
         @Override
         public int hashCode() {
             int result = readAccessorName != null ? readAccessorName.hashCode() : 0;
-            result = 31 * result + ( presenceCheckerName != null ? presenceCheckerName.hashCode() : 0 );
+            result = 31 * result + ( presenceChecker != null ? presenceChecker.hashCode() : 0 );
             result = 31 * result + ( type != null ? type.hashCode() : 0 );
             return result;
         }

processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java

@@ -28,8 +28,12 @@ import org.mapstruct.ap.internal.model.common.BuilderType;
 import org.mapstruct.ap.internal.model.common.FormattingParameters;
 import org.mapstruct.ap.internal.model.common.ModelElement;
 import org.mapstruct.ap.internal.model.common.Parameter;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.common.SourceRHS;
 import org.mapstruct.ap.internal.model.common.Type;
+import org.mapstruct.ap.internal.model.presence.AllPresenceChecksPresenceCheck;
+import org.mapstruct.ap.internal.model.presence.NullPresenceCheck;
+import org.mapstruct.ap.internal.model.presence.SourceReferenceMethodPresenceCheck;
 import org.mapstruct.ap.internal.model.source.DelegatingOptions;
 import org.mapstruct.ap.internal.model.source.MappingControl;
 import org.mapstruct.ap.internal.model.source.MappingOptions;
@@ -609,30 +613,43 @@ public class PropertyMapping extends ModelElement {
             }
         }
 
-        private String getSourcePresenceCheckerRef( SourceReference sourceReference ) {
+        private PresenceCheck getSourcePresenceCheckerRef(SourceReference sourceReference ) {
-            String sourcePresenceChecker = null;
+            PresenceCheck sourcePresenceChecker = null;
             if ( !sourceReference.getPropertyEntries().isEmpty() ) {
                 Parameter sourceParam = sourceReference.getParameter();
                 // TODO is first correct here?? shouldn't it be last since the remainer is checked
                 // in the forged method?
                 PropertyEntry propertyEntry = sourceReference.getShallowestProperty();
                 if ( propertyEntry.getPresenceChecker() != null ) {
-                    sourcePresenceChecker = sourceParam.getName()
+                    List<PresenceCheck> presenceChecks = new ArrayList<>();
-                        + "." + propertyEntry.getPresenceChecker().getSimpleName() + "()";
+                    presenceChecks.add( new SourceReferenceMethodPresenceCheck(
+                        sourceParam.getName(),
+                        propertyEntry.getPresenceChecker().getSimpleName()
+                    ) );
 
                     String variableName = sourceParam.getName() + "."
                         + propertyEntry.getReadAccessor().getSimpleName() + "()";
                     for (int i = 1; i < sourceReference.getPropertyEntries().size(); i++) {
                         PropertyEntry entry = sourceReference.getPropertyEntries().get( i );
                         if (entry.getPresenceChecker() != null && entry.getReadAccessor() != null) {
-                            sourcePresenceChecker += " && " + variableName + " != null && "
+                            presenceChecks.add( new NullPresenceCheck( variableName ) );
-                                + variableName + "." + entry.getPresenceChecker().getSimpleName() + "()";
+                            presenceChecks.add( new SourceReferenceMethodPresenceCheck(
+                                variableName,
+                                entry.getPresenceChecker().getSimpleName()
+                            ) );
                             variableName = variableName + "." + entry.getReadAccessor().getSimpleName() + "()";
                         }
                         else {
                             break;
                         }
                     }
+
+                    if ( presenceChecks.size() == 1 ) {
+                        sourcePresenceChecker = presenceChecks.get( 0 );
+                    }
+                    else {
+                        sourcePresenceChecker = new AllPresenceChecksPresenceCheck( presenceChecks );
+                    }
                 }
             }
             return sourcePresenceChecker;

processor/src/main/java/org/mapstruct/ap/internal/model/TypeConversion.java

@@ -11,6 +11,7 @@ import java.util.Set;
 
 import org.mapstruct.ap.internal.model.common.Assignment;
 import org.mapstruct.ap.internal.model.common.ModelElement;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.common.Type;
 
 /**
@@ -79,7 +80,7 @@ public class TypeConversion extends ModelElement implements Assignment {
     }
 
     @Override
-    public String getSourcePresenceCheckerReference() {
+    public PresenceCheck getSourcePresenceCheckerReference() {
         return assignment.getSourcePresenceCheckerReference();
     }
 

processor/src/main/java/org/mapstruct/ap/internal/model/assignment/AssignmentWrapper.java

@@ -10,6 +10,7 @@ import java.util.Set;
 
 import org.mapstruct.ap.internal.model.common.Assignment;
 import org.mapstruct.ap.internal.model.common.ModelElement;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.common.Type;
 
 /**
@@ -57,7 +58,7 @@ public abstract class AssignmentWrapper extends ModelElement implements Assignme
     }
 
     @Override
-    public String getSourcePresenceCheckerReference() {
+    public PresenceCheck getSourcePresenceCheckerReference() {
         return decoratedAssignment.getSourcePresenceCheckerReference();
     }
 

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

@@ -90,7 +90,7 @@ public interface Assignment {
      *
      * @return source reference
      */
-    String getSourcePresenceCheckerReference();
+    PresenceCheck getSourcePresenceCheckerReference();
 
     /**
      * the source type used in the matching process

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

@@ -0,0 +1,24 @@
+/*
+ * 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.internal.model.common;
+
+import java.util.Set;
+
+/**
+ * Marker interface for presence checks.
+ *
+ * @author Filip Hrisafov
+ */
+public interface PresenceCheck {
+
+    /**
+     * returns all types required as import by the presence check.
+     *
+     * @return imported types
+     */
+    Set<Type> getImportTypes();
+
+}

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

@@ -7,6 +7,7 @@ package org.mapstruct.ap.internal.model.common;
 
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Stream;
@@ -30,7 +31,7 @@ public class SourceRHS extends ModelElement implements Assignment {
     private String sourceLoopVarName;
     private final Set<String> existingVariableNames;
     private final String sourceErrorMessagePart;
-    private final String sourcePresenceCheckerReference;
+    private final PresenceCheck sourcePresenceCheckerReference;
     private boolean useElementAsSourceTypeForMatching = false;
     private final String sourceParameterName;
 
@@ -39,7 +40,7 @@ public class SourceRHS extends ModelElement implements Assignment {
         this( sourceReference, sourceReference, null, sourceType, existingVariableNames, sourceErrorMessagePart );
     }
 
-    public SourceRHS(String sourceParameterName, String sourceReference, String sourcePresenceCheckerReference,
+    public SourceRHS(String sourceParameterName, String sourceReference, PresenceCheck sourcePresenceCheckerReference,
         Type sourceType, Set<String> existingVariableNames,  String sourceErrorMessagePart ) {
         this.sourceReference = sourceReference;
         this.sourceType = sourceType;
@@ -60,7 +61,7 @@ public class SourceRHS extends ModelElement implements Assignment {
     }
 
     @Override
-    public String getSourcePresenceCheckerReference() {
+    public PresenceCheck getSourcePresenceCheckerReference() {
         return sourcePresenceCheckerReference;
     }
 
@@ -96,6 +97,10 @@ public class SourceRHS extends ModelElement implements Assignment {
 
     @Override
     public Set<Type> getImportTypes() {
+        if ( sourcePresenceCheckerReference != null ) {
+            return sourcePresenceCheckerReference.getImportTypes();
+        }
+
         return Collections.emptySet();
     }
 

processor/src/main/java/org/mapstruct/ap/internal/model/presence/AllPresenceChecksPresenceCheck.java

@@ -0,0 +1,59 @@
+/*
+ * 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.internal.model.presence;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+import org.mapstruct.ap.internal.model.common.ModelElement;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
+import org.mapstruct.ap.internal.model.common.Type;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class AllPresenceChecksPresenceCheck extends ModelElement implements PresenceCheck {
+
+    private final Collection<PresenceCheck> presenceChecks;
+
+    public AllPresenceChecksPresenceCheck(Collection<PresenceCheck> presenceChecks) {
+        this.presenceChecks = presenceChecks;
+    }
+
+    public Collection<PresenceCheck> getPresenceChecks() {
+        return presenceChecks;
+    }
+
+    @Override
+    public Set<Type> getImportTypes() {
+        Set<Type> importTypes = new HashSet<>();
+        for ( PresenceCheck presenceCheck : presenceChecks ) {
+            importTypes.addAll( presenceCheck.getImportTypes() );
+        }
+
+        return importTypes;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if ( this == o ) {
+            return true;
+        }
+        if ( o == null || getClass() != o.getClass() ) {
+            return false;
+        }
+        AllPresenceChecksPresenceCheck that = (AllPresenceChecksPresenceCheck) o;
+        return Objects.equals( presenceChecks, that.presenceChecks );
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash( presenceChecks );
+    }
+}

processor/src/main/java/org/mapstruct/ap/internal/model/presence/NullPresenceCheck.java

@@ -0,0 +1,52 @@
+/*
+ * 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.internal.model.presence;
+
+import java.util.Collections;
+import java.util.Objects;
+import java.util.Set;
+
+import org.mapstruct.ap.internal.model.common.ModelElement;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
+import org.mapstruct.ap.internal.model.common.Type;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class NullPresenceCheck extends ModelElement implements PresenceCheck {
+
+    private final String sourceReference;
+
+    public NullPresenceCheck(String sourceReference) {
+        this.sourceReference = sourceReference;
+    }
+
+    public String getSourceReference() {
+        return sourceReference;
+    }
+
+    @Override
+    public Set<Type> getImportTypes() {
+        return Collections.emptySet();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if ( this == o ) {
+            return true;
+        }
+        if ( o == null || getClass() != o.getClass() ) {
+            return false;
+        }
+        NullPresenceCheck that = (NullPresenceCheck) o;
+        return Objects.equals( sourceReference, that.sourceReference );
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash( sourceReference );
+    }
+}

processor/src/main/java/org/mapstruct/ap/internal/model/presence/SourceReferenceMethodPresenceCheck.java

@@ -0,0 +1,59 @@
+/*
+ * 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.internal.model.presence;
+
+import java.util.Collections;
+import java.util.Objects;
+import java.util.Set;
+
+import org.mapstruct.ap.internal.model.common.ModelElement;
+import org.mapstruct.ap.internal.model.common.PresenceCheck;
+import org.mapstruct.ap.internal.model.common.Type;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class SourceReferenceMethodPresenceCheck extends ModelElement implements PresenceCheck {
+
+    private final String sourceReference;
+    private final String methodName;
+
+    public SourceReferenceMethodPresenceCheck(String sourceReference, String methodName) {
+        this.sourceReference = sourceReference;
+        this.methodName = methodName;
+    }
+
+    public String getSourceReference() {
+        return sourceReference;
+    }
+
+    public String getMethodName() {
+        return methodName;
+    }
+
+    @Override
+    public Set<Type> getImportTypes() {
+        return Collections.emptySet();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if ( this == o ) {
+            return true;
+        }
+        if ( o == null || getClass() != o.getClass() ) {
+            return false;
+        }
+        SourceReferenceMethodPresenceCheck that = (SourceReferenceMethodPresenceCheck) o;
+        return Objects.equals( sourceReference, that.sourceReference ) &&
+            Objects.equals( methodName, that.methodName );
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash( sourceReference, methodName );
+    }
+}

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

@@ -11,13 +11,13 @@
         return ${returnType.null};
     }
 <#list propertyEntries as entry>
-    <#if entry.presenceCheckerName?? >
+    <#if entry.presenceChecker?? >
-    if ( <#if entry_index != 0><@localVarName index=entry_index/> == null || </#if>!<@localVarName index=entry_index/>.${entry.presenceCheckerName}() ) {
+    if ( <#if entry_index != 0>${entry.previousPropertyName} == null || </#if>!<@includeModel object=entry.presenceChecker /> ) {
         return ${returnType.null};
     }
     </#if>
-    <@includeModel object=entry.type.typeBound/> ${entry.name} = <@localVarName index=entry_index/>.${entry.accessorName};
+    <@includeModel object=entry.type.typeBound/> ${entry.name} = ${entry.previousPropertyName}.${entry.accessorName};
-    <#if !entry.presenceCheckerName?? >
+    <#if !entry.presenceChecker?? >
     <#if !entry.type.primitive>
     if ( ${entry.name} == null ) {
         return ${returnType.null};
@@ -29,7 +29,6 @@
     </#if>
 </#list>
 }
-<#macro localVarName index><#if index == 0>${sourceParameter.name}<#else>${propertyEntries[index-1].name}</#if></#macro>
 <#macro throws>
     <#if (thrownTypes?size > 0)><#lt> throws </#if><@compress single_line=true>
         <#list thrownTypes as exceptionType>

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

@@ -15,7 +15,7 @@
 -->
 <#macro handleSourceReferenceNullCheck>
     <#if sourcePresenceCheckerReference??>
-        if ( ${sourcePresenceCheckerReference} ) {
+        if ( <@includeModel object=sourcePresenceCheckerReference /> ) {
             <#nested>
         }
         <@elseDefaultAssignment/>
@@ -57,7 +57,7 @@
 -->
 <#macro handleLocalVarNullCheck needs_explicit_local_var>
   <#if sourcePresenceCheckerReference??>
-    if ( ${sourcePresenceCheckerReference} ) {
+    if ( <@includeModel object=sourcePresenceCheckerReference /> ) {
       <#if needs_explicit_local_var>
         <@includeModel object=nullCheckLocalVarType/> ${nullCheckLocalVarName} = <@lib.handleAssignment/>;
         <#nested>

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

@@ -0,0 +1,16 @@
+<#--
+
+    Copyright MapStruct Authors.
+
+    Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+
+-->
+<#-- @ftlvariable name="" type="org.mapstruct.ap.internal.model.presence.AllPresenceChecksPresenceCheck" -->
+<@compress single_line=true>
+<#list presenceChecks as presenceCheck>
+    <#if presenceCheck_index != 0>
+        &&
+    </#if>
+    <@includeModel object=presenceCheck />
+</#list>
+</@compress>

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

@@ -0,0 +1,9 @@
+<#--
+
+    Copyright MapStruct Authors.
+
+    Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+
+-->
+<#-- @ftlvariable name="" type="org.mapstruct.ap.internal.model.presence.NullPresenceCheck" -->
+${sourceReference} != null

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

@@ -0,0 +1,9 @@
+<#--
+
+    Copyright MapStruct Authors.
+
+    Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+
+-->
+<#-- @ftlvariable name="" type="org.mapstruct.ap.internal.model.presence.SourceReferenceMethodPresenceCheck" -->
+${sourceReference}.${methodName}()