Uast: Ability to get the default class type from UClass

plugins/uast-common/src/org/jetbrains/uast/declarations/UClass.kt

@@ -18,9 +18,13 @@ package org.jetbrains.uast
 import org.jetbrains.uast.kinds.UastClassKind
 
 interface UClass : UDeclaration, UFqNamed, UModifierOwner, UAnnotated {
+    /* The simple class name is only for the debug purposes. Do not check against it in the production code */
+    override val name: String
+
     val isAnonymous: Boolean
     val visibility: UastVisibility
     val kind: UastClassKind
+    val defaultType: UType
 
     val companions: List<UClass>
 
@@ -78,7 +82,7 @@ object UClassNotResolved : UClass {
     override val declarations = emptyList<UDeclaration>()
     override fun isSubclassOf(name: String) = false
     override val companions = emptyList<UClass>()
-
+    override val defaultType = UastErrorType
     override val nameElement = null
     override val parent = null
     override val name = "<class not resolved>"

plugins/uast-common/src/org/jetbrains/uast/declarations/UType.kt

@@ -34,4 +34,13 @@ interface UTypeReference : UDeclaration, UResolvable, NoTraverse {
 
     override fun resolve(context: UastContext): UClass?
     override fun resolveOrEmpty(context: UastContext) = resolve(context) ?: UClassNotResolved
+}
+
+object UastErrorType : UType, NoAnnotations {
+    override val isInt = false
+    override val parent = null
+    override val name = "<error>"
+    override val fqName = null
+    override val isBoolean = false
+    override fun resolve(context: UastContext) = null
 }

plugins/uast-java/src/org/jetbrains/uast/java/declarations/JavaUClass.kt

@@ -16,6 +16,7 @@
 package org.jetbrains.uast.java
 
 import com.intellij.psi.*
+import com.intellij.psi.util.PsiTypesUtil
 import org.jetbrains.uast.*
 import org.jetbrains.uast.kinds.UastClassKind
 import org.jetbrains.uast.psi.PsiElementBacked
@@ -50,6 +51,8 @@ class JavaUClass(
         }
     }
 
+    override val defaultType by lz { JavaConverter.convert(PsiTypesUtil.getClassType(psi), this) }
+
     override val companions: List<UClass>
         get() = emptyList()
 

plugins/uast-kotlin/src/org/jetbrains/kotlin/uast/KotlinUastLanguagePlugin.kt

@@ -169,9 +169,9 @@ internal object KotlinConverter : UastConverter {
     }
 
     internal fun convert(typeReference: KtTypeReference?, parent: UElement): UType {
-        if (typeReference == null) return KotlinUErrorType
+        if (typeReference == null) return UastErrorType
         val bindingContext = typeReference.analyze(BodyResolveMode.PARTIAL)
-        val type = bindingContext[BindingContext.TYPE, typeReference] ?: return KotlinUErrorType
+        val type = bindingContext[BindingContext.TYPE, typeReference] ?: return UastErrorType
         return convert(type, typeReference.project, parent)
     }
 

plugins/uast-kotlin/src/org/jetbrains/kotlin/uast/declarations/KotlinUClass.kt

@@ -66,6 +66,11 @@ class KotlinUClass(
         }
     }
 
+    override val defaultType by lz {
+        val type = resolveToDescriptor()?.defaultType ?: return@lz UastErrorType
+        KotlinConverter.convert(type, psi.project, this)
+    }
+
     override val companions by lz {
         (psi as? KtClass)?.getCompanionObjects()?.map { KotlinConverter.convert(it, this) } ?: emptyList()
     }

plugins/uast-kotlin/src/org/jetbrains/kotlin/uast/declarations/KotlinUType.kt

@@ -46,13 +46,4 @@ class KotlinUType(
 
     //TODO
     override val annotations = emptyList<UAnnotation>()
-}
-
-object KotlinUErrorType : UType, NoAnnotations {
-    override val isInt = false
-    override val parent = null
-    override val name = "<error>"
-    override val fqName = null
-    override val isBoolean = false
-    override fun resolve(context: UastContext) = null
 }

plugins/uast-kotlin/src/org/jetbrains/kotlin/uast/declarations/KotlinUVariable.kt

@@ -37,8 +37,8 @@ open class KotlinUVariable(
     override val initializer by lz { KotlinConverter.convertOrEmpty(psi.initializer, this) }
 
     override val type by lz {
-        val descriptor = psi.resolveToDescriptorIfAny() as? CallableDescriptor ?: return@lz KotlinUErrorType
-        val type = descriptor.returnType ?: return@lz KotlinUErrorType
+        val descriptor = psi.resolveToDescriptorIfAny() as? CallableDescriptor ?: return@lz UastErrorType
+        val type = descriptor.returnType ?: return@lz UastErrorType
         KotlinConverter.convert(type, psi.project, this)
     }
 
@@ -58,11 +58,12 @@ class KotlinDestructuredUVariable(
         parent: UElement
 ) : KotlinUVariable(entry, parent) {
     override lateinit var initializer: UExpression
+        internal set
 
     override val type by lz {
         val bindingContext = entry.analyze(BodyResolveMode.PARTIAL)
-        val resolvedCall = bindingContext[BindingContext.COMPONENT_RESOLVED_CALL, entry] ?: return@lz KotlinUErrorType
-        val returnType = resolvedCall.resultingDescriptor.returnType ?: return@lz KotlinUErrorType
+        val resolvedCall = bindingContext[BindingContext.COMPONENT_RESOLVED_CALL, entry] ?: return@lz UastErrorType
+        val returnType = resolvedCall.resultingDescriptor.returnType ?: return@lz UastErrorType
         KotlinConverter.convert(returnType, entry.project, this)
     }
 }
@@ -75,7 +76,7 @@ class KotlinDestructuringUVariable(
     override val initializer by lz { KotlinConverter.convertOrEmpty(psi.initializer, this) }
     override val kind = UastVariableKind.LOCAL_VARIABLE
     override val type: UType
-        get() = initializer.getExpressionType() ?: KotlinUErrorType
+        get() = initializer.getExpressionType() ?: UastErrorType
 
     override val nameElement = null
     override fun hasModifier(modifier: UastModifier) = false
@@ -91,13 +92,13 @@ class KotlinParameterUVariable(
 
     override val nameElement by lz { KotlinConverter.asSimpleReference(psi.nameIdentifier, this) }
 
-    override val initializer by lz { KotlinConverter.convertOrEmpty(psi.defaultValue, this) }
+    override val initializer by lz { KotlinConverter.convert(psi.defaultValue, this) as? UExpression }
 
     override val kind = UastVariableKind.VALUE_PARAMETER
 
     override val type by lz {
         val bindingContext = psi.analyze(BodyResolveMode.PARTIAL)
-        val param = bindingContext[BindingContext.VALUE_PARAMETER, psi] ?: return@lz KotlinUErrorType
+        val param = bindingContext[BindingContext.VALUE_PARAMETER, psi] ?: return@lz UastErrorType
         KotlinConverter.convert(param.type, psi.project, this)
     }