GROOVY-11443: Support multiple Requires/Ensures/Invariant annotations…

… in groovy-contracts

src/main/java/org/codehaus/groovy/ast/tools/GeneralUtils.java

@@ -770,6 +770,10 @@ public static MapEntryExpression mapEntryX(final String key, final Expression va
         return new MapEntryExpression(constX(key), valueExpr);
     }
 
+    public static MapExpression mapX() {
+        return new MapExpression();
+    }
+
     public static MapExpression mapX(final List<MapEntryExpression> expressions) {
         return new MapExpression(expressions);
     }

subprojects/groovy-contracts/src/main/java/groovy/contracts/Ensures.java

@@ -24,6 +24,7 @@
 import org.apache.groovy.lang.annotation.Incubating;
 
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -80,7 +81,8 @@
 @Target({ElementType.CONSTRUCTOR, ElementType.METHOD})
 @Incubating
 @Postcondition
+@Repeatable(EnsuresConditions.class)
 @AnnotationProcessorImplementation(EnsuresAnnotationProcessor.class)
 public @interface Ensures {
     Class value();
-}
+}

subprojects/groovy-contracts/src/main/java/groovy/contracts/EnsuresConditions.java

@@ -0,0 +1,36 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package groovy.contracts;
+
+import org.apache.groovy.lang.annotation.Incubating;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Represents multiple postconditions.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.CONSTRUCTOR, ElementType.METHOD})
+@Incubating
+public @interface EnsuresConditions {
+    Ensures[] value();
+}

subprojects/groovy-contracts/src/main/java/groovy/contracts/Invariant.java

@@ -24,6 +24,7 @@
 import org.apache.groovy.lang.annotation.Incubating;
 
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -53,7 +54,8 @@
 @Target(ElementType.TYPE)
 @Incubating
 @ClassInvariant
+@Repeatable(Invariants.class)
 @AnnotationProcessorImplementation(ClassInvariantAnnotationProcessor.class)
 public @interface Invariant {
     Class value();
-}
+}

subprojects/groovy-contracts/src/main/java/groovy/contracts/Invariants.java

@@ -0,0 +1,36 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package groovy.contracts;
+
+import org.apache.groovy.lang.annotation.Incubating;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Represents multiple invariants
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Incubating
+public @interface Invariants {
+    Invariant[] value();
+}

subprojects/groovy-contracts/src/main/java/groovy/contracts/Requires.java

@@ -24,6 +24,7 @@
 import org.apache.groovy.lang.annotation.Incubating;
 
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -58,6 +59,7 @@
 @Incubating
 @Precondition
 @AnnotationProcessorImplementation(RequiresAnnotationProcessor.class)
+@Repeatable(RequiresConditions.class)
 public @interface Requires {
     Class value();
-}
+}

subprojects/groovy-contracts/src/main/java/groovy/contracts/RequiresConditions.java

@@ -0,0 +1,36 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package groovy.contracts;
+
+import org.apache.groovy.lang.annotation.Incubating;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Represents multiple preconditions.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.CONSTRUCTOR, ElementType.METHOD})
+@Incubating
+public @interface RequiresConditions {
+    Requires[] value();
+}

subprojects/groovy-contracts/src/main/java/org/apache/groovy/contracts/ast/ClosureExpressionEvaluationASTTransformation.java

@@ -37,45 +37,46 @@
 import java.util.List;
 
 /**
- * Evaluates {@link org.codehaus.groovy.ast.expr.ClosureExpression} instances in as actual annotation parameters and
+ * Evaluates {@link org.codehaus.groovy.ast.expr.ClosureExpression} instances in annotation parameters and
  * generates special contract closure classes from them.
  */
 @GroovyASTTransformation(phase = CompilePhase.SEMANTIC_ANALYSIS)
 public class ClosureExpressionEvaluationASTTransformation extends BaseASTTransformation {
 
+    /**
+     * {@link org.codehaus.groovy.transform.ASTTransformation#visit(org.codehaus.groovy.ast.ASTNode[], org.codehaus.groovy.control.SourceUnit)}
+     */
+    @Override
+    public void visit(ASTNode[] nodes, SourceUnit unit) {
+        final ModuleNode moduleNode = unit.getAST();
+
+        ReaderSource source = getReaderSource(unit);
+        final List<ClassNode> classNodes = new ArrayList<>(moduleNode.getClasses());
+
+        generateAnnotationClosureClasses(unit, source, classNodes);
+    }
+
     private void generateAnnotationClosureClasses(SourceUnit unit, ReaderSource source, List<ClassNode> classNodes) {
         final AnnotationClosureVisitor annotationClosureVisitor = new AnnotationClosureVisitor(unit, source);
 
         for (final ClassNode classNode : classNodes) {
             annotationClosureVisitor.visitClass(classNode);
 
-            if (!CandidateChecks.isContractsCandidate(classNode)) continue;
+            if (!CandidateChecks.isContractsCandidate(classNode) && !CandidateChecks.isInterfaceContractsCandidate(classNode))
+                continue;
 
             final ContractElementVisitor contractElementVisitor = new ContractElementVisitor(unit, source);
             contractElementVisitor.visitClass(classNode);
-
             if (!contractElementVisitor.isFoundContractElement()) continue;
 
             annotationClosureVisitor.visitClass(classNode);
             markClassNodeAsContracted(classNode);
+            if (classNode.isInterface()) continue;
 
             new ConfigurationSetup().init(classNode);
         }
     }
 
-    /**
-     * {@link org.codehaus.groovy.transform.ASTTransformation#visit(org.codehaus.groovy.ast.ASTNode[], org.codehaus.groovy.control.SourceUnit)}
-     */
-    @Override
-    public void visit(ASTNode[] nodes, SourceUnit unit) {
-        final ModuleNode moduleNode = unit.getAST();
-
-        ReaderSource source = getReaderSource(unit);
-        final List<ClassNode> classNodes = new ArrayList<ClassNode>(moduleNode.getClasses());
-
-        generateAnnotationClosureClasses(unit, source, classNodes);
-    }
-
     private void markClassNodeAsContracted(final ClassNode classNode) {
         final ClassNode contractedAnnotationClassNode = ClassHelper.makeWithoutCaching(Contracted.class);
 

subprojects/groovy-contracts/src/main/java/org/apache/groovy/contracts/ast/visitor/AnnotationClosureVisitor.java

@@ -107,11 +107,11 @@ public AnnotationClosureVisitor(final SourceUnit sourceUnit, final ReaderSource
 
     @Override
     public void visitClass(ClassNode classNode) {
-        if (classNode == null || !(CandidateChecks.isInterfaceContractsCandidate(classNode) || CandidateChecks.isContractsCandidate(classNode))) return;
+        if (classNode == null || !(CandidateChecks.isContractsCandidate(classNode) || CandidateChecks.isInterfaceContractsCandidate(classNode))) return;
 
         this.classNode = classNode;
 
-        if (classNode.getNodeMetaData(PROCESSED) == null && CandidateChecks.isContractsCandidate(classNode)) {
+        if (classNode.getNodeMetaData(PROCESSED) == null) {
             List<AnnotationNode> annotationNodes = AnnotationUtils.hasMetaAnnotations(classNode, ContractElement.class.getName());
             for (AnnotationNode annotationNode : annotationNodes) {
                 ClosureExpression closureExpression = getOriginalCondition(annotationNode);