[groovy] resolve method references with top level type as receiver

Support top-level type for reference expressions and index property expressions.
This fixes cycle when operator resolution wanted receiver type and receiver type required inference from context,
i.e. from resolved operator.

GitOrigin-RevId: 2c2818e2b5689ddf0c65aac2d87b76d11f1f2ebc

plugins/groovy/groovy-psi/src/org/jetbrains/plugins/groovy/lang/resolve/processors/inference/inference.kt

@@ -11,6 +11,7 @@ import org.jetbrains.plugins.groovy.lang.psi.api.SpreadState
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrMethodCall
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression
+import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.path.GrIndexProperty
 import org.jetbrains.plugins.groovy.lang.psi.impl.PsiImplUtil.getQualifierType
 import org.jetbrains.plugins.groovy.lang.psi.impl.statements.expressions.TypesUtil
 import org.jetbrains.plugins.groovy.lang.psi.typeEnhancers.GrTypeConverter
@@ -24,22 +25,23 @@ import org.jetbrains.plugins.groovy.lang.resolve.processors.ClassHint
 import org.jetbrains.plugins.groovy.lang.typing.devoid
 
 fun getTopLevelType(expression: GrExpression): PsiType? {
-  if (expression is GrMethodCall) {
-    val resolved = expression.advancedResolve() as? GroovyMethodResult
-    resolved?.candidate?.let {
-      val session = GroovyInferenceSessionBuilder(expression, it, resolved.contextSubstitutor)
-        .resolveMode(false)
-        .build()
-      return session.inferSubst().substitute(PsiUtil.getSmartReturnType(it.method).devoid(expression))
-    }
-    return null
-  }
-
   if (expression is GrFunctionalExpression) {
     return TypesUtil.createTypeByFQClassName(GroovyCommonClassNames.GROOVY_LANG_CLOSURE, expression)
   }
 
-  return expression.type
+  val result = when (expression) {
+    is GrMethodCall -> expression.advancedResolve() as? GroovyMethodResult
+    is GrReferenceExpression -> expression.rValueReference?.advancedResolve() as? GroovyMethodResult ?: return expression.type
+    is GrIndexProperty -> expression.rValueReference?.advancedResolve() as? GroovyMethodResult ?: return expression.type
+    else -> return expression.type
+  }
+
+  return result?.candidate?.let {
+    val session = GroovyInferenceSessionBuilder(expression, it, result.contextSubstitutor)
+      .resolveMode(false)
+      .build()
+    session.inferSubst().substitute(PsiUtil.getSmartReturnType(it.method).devoid(expression))
+  }
 }
 
 fun buildQualifier(ref: GrReferenceExpression?, state: ResolveState): Argument {

plugins/groovy/groovy-psi/src/org/jetbrains/plugins/groovy/lang/resolve/receiver.kt

@@ -18,7 +18,7 @@ import org.jetbrains.plugins.groovy.lang.resolve.processors.ClassHint
 import org.jetbrains.plugins.groovy.lang.resolve.processors.ClassHint.STATIC_CONTEXT
 
 fun Argument.processReceiver(processor: PsiScopeProcessor, state: ResolveState, place: PsiElement): Boolean {
-  val receiverType: PsiType = type ?: TypesUtil.getJavaLangObject(place) ?: return true
+  val receiverType: PsiType = topLevelType ?: TypesUtil.getJavaLangObject(place) ?: return true
   return receiverType.doProcessReceiverType0(processor, state.put(ClassHint.RECEIVER, this), place)
 }
 

plugins/groovy/test/org/jetbrains/plugins/groovy/lang/resolve/SubstitutorInferenceTest.groovy

@@ -9,6 +9,7 @@ import org.jetbrains.plugins.groovy.GroovyProjectDescriptors
 import org.jetbrains.plugins.groovy.lang.psi.api.GroovyResolveResult
 import org.jetbrains.plugins.groovy.lang.psi.api.auxiliary.GrListOrMap
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.*
+import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.path.GrIndexProperty
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrMethod
 import org.jetbrains.plugins.groovy.util.LightProjectTest
 import org.jetbrains.plugins.groovy.util.ResolveTest
@@ -49,6 +50,9 @@ class IdCallable {
 class GenericPropertyContainer {
   def <T> I<T> getGenericProperty() {}
   def <T> void setGenericProperty(I<T> c) {}
+  
+  def <T> List<T> getGenericList() {}
+  def <T> void setGenericList(List<T> l) {}
 }
 
 class Files {
@@ -242,6 +246,38 @@ static <T> T ppp(Producer<T> p) {}
     assertSubstitutor(op.reference.advancedResolve(), 'java.io.File')
   }
 
+  @Test
+  void 'plus assignment generic property r-value'() {
+    def ref = elementUnderCaret('new GenericPropertyContainer().<caret>genericList += new ArrayList<String>()', GrReferenceExpression)
+    assertSubstitutor(ref.RValueReference.advancedResolve(), JAVA_LANG_STRING)
+  }
+
+  @Test
+  void 'plus assignment generic property'() {
+    def op = elementUnderCaret('new GenericPropertyContainer().genericList <caret>+= new ArrayList<String>()', GrAssignmentExpression)
+    assertSubstitutor(op.reference.advancedResolve(), JAVA_LANG_STRING)
+  }
+
+  @Ignore("we don't yet infer l-value substitutors")
+  @Test
+  void 'plus assignment generic property l-value'() {
+    def ref = elementUnderCaret('new GenericPropertyContainer().<caret>genericList += new ArrayList<String>()', GrReferenceExpression)
+    assertSubstitutor(ref.LValueReference.advancedResolve(), JAVA_LANG_STRING)
+  }
+
+  @Test
+  void 'plus assignment with index r-value'() {
+    def op = elementUnderCaret('Map<Number, String> mns; mns<caret>[42] += "foo"', GrIndexProperty)
+    assertSubstitutor(op.RValueReference.advancedResolve(), JAVA_LANG_NUMBER, JAVA_LANG_STRING)
+  }
+
+  @Ignore("we don't yet infer l-value substitutors")
+  @Test
+  void 'plus assignment with index l-value'() {
+    def op = elementUnderCaret('Map<Number, String> mns; mns<caret>[42] += "foo"', GrIndexProperty)
+    assertSubstitutor(op.LValueReference.advancedResolve(), JAVA_LANG_NUMBER, JAVA_LANG_STRING)
+  }
+
   @Test
   void 'same method nested'() {
     def call = elementUnderCaret '''\