[FIR IDE] Make KtSmartcastProvider report resolved smartcast type

idea/idea-fir/src/org/jetbrains/kotlin/idea/fir/highlighter/visitors/ExpressionsSmartcastHighlightingVisitor.kt

@@ -8,8 +8,8 @@ package org.jetbrains.kotlin.idea.fir.highlighter.visitors
 import com.intellij.lang.annotation.AnnotationHolder
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.idea.KotlinIdeaAnalysisBundle
-import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
 import org.jetbrains.kotlin.idea.frontend.api.ImplicitReceiverSmartcastKind
+import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
 import org.jetbrains.kotlin.idea.highlighter.KotlinHighlightingColors
 import org.jetbrains.kotlin.psi.*
 
@@ -18,25 +18,23 @@ internal class ExpressionsSmartcastHighlightingVisitor(
     holder: AnnotationHolder
 ) : FirAfterResolveHighlightingVisitor(analysisSession, holder) {
     override fun visitExpression(expression: KtExpression) = with(analysisSession) {
-        expression.getImplicitReceiverSmartCasts().forEach { (types, kind) ->
+        expression.getImplicitReceiverSmartCast().forEach { (type, kind) ->
             val receiverName = when (kind) {
                 ImplicitReceiverSmartcastKind.EXTENSION -> KotlinIdeaAnalysisBundle.message("extension.implicit.receiver")
                 ImplicitReceiverSmartcastKind.DISPATCH -> KotlinIdeaAnalysisBundle.message("implicit.receiver")
             }
 
-            types.forEach { type ->
-                createInfoAnnotation(
-                    expression,
-                    KotlinIdeaAnalysisBundle.message(
-                        "0.smart.cast.to.1",
-                        receiverName,
-                        type.asStringForDebugging()
-                    ),
-                    KotlinHighlightingColors.SMART_CAST_RECEIVER
-                )
-            }
+            createInfoAnnotation(
+                expression,
+                KotlinIdeaAnalysisBundle.message(
+                    "0.smart.cast.to.1",
+                    receiverName,
+                    type.asStringForDebugging()
+                ),
+                KotlinHighlightingColors.SMART_CAST_RECEIVER
+            )
         }
-        expression.getSmartCasts()?.forEach { type ->
+        expression.getSmartCast()?.let { type ->
             createInfoAnnotation(
                 getSmartCastTarget(expression),
                 KotlinIdeaAnalysisBundle.message(
@@ -47,8 +45,6 @@ internal class ExpressionsSmartcastHighlightingVisitor(
             )
         }
 
-        //todo smartcast to null
-
         super.visitExpression(expression)
     }
 }

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/ImplicitReceiverSmartCast.kt

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.idea.frontend.api
 
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 
-data class ImplicitReceiverSmartCast(val types: Collection<KtType>, val kind: ImplicitReceiverSmartcastKind)
+data class ImplicitReceiverSmartCast(val type: KtType, val kind: ImplicitReceiverSmartcastKind)
 
 enum class ImplicitReceiverSmartcastKind {
     DISPATCH, EXTENSION

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/KtAnalysisSession.kt

@@ -61,10 +61,10 @@ abstract class KtAnalysisSession(final override val token: ValidityToken) : Vali
     fun KtCallableSymbol.getIntersectionOverriddenSymbols(): Collection<KtCallableSymbol> =
         symbolDeclarationOverridesProvider.getIntersectionOverriddenSymbols(this)
 
-    fun KtExpression.getSmartCasts(): Collection<KtType> = smartCastProvider.getSmartCastedToTypes(this)
+    fun KtExpression.getSmartCast(): KtType? = smartCastProvider.getSmartCastedToType(this)
 
-    fun KtExpression.getImplicitReceiverSmartCasts(): Collection<ImplicitReceiverSmartCast> =
-        smartCastProvider.getImplicitReceiverSmartCasts(this)
+    fun KtExpression.getImplicitReceiverSmartCast(): Collection<ImplicitReceiverSmartCast> =
+        smartCastProvider.getImplicitReceiverSmartCast(this)
 
     fun KtExpression.getKtType(): KtType = expressionTypeProvider.getKtExpressionType(this)
 

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/components/KtSmartCastProvider.kt

@@ -10,6 +10,6 @@ import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.psi.KtExpression
 
 abstract class KtSmartCastProvider : KtAnalysisSessionComponent() {
-    abstract fun getSmartCastedToTypes(expression: KtExpression): Collection<KtType>
-    abstract fun getImplicitReceiverSmartCasts(expression: KtExpression): Collection<ImplicitReceiverSmartCast>
+    abstract fun getSmartCastedToType(expression: KtExpression): KtType?
+    abstract fun getImplicitReceiverSmartCast(expression: KtExpression): Collection<ImplicitReceiverSmartCast>
 }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirSmartcastProvider.kt

@@ -7,6 +7,8 @@ package org.jetbrains.kotlin.idea.frontend.api.fir.components
 
 import org.jetbrains.kotlin.fir.expressions.FirExpressionWithSmartcast
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.coneTypeSafe
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFirSafe
 import org.jetbrains.kotlin.idea.frontend.api.ImplicitReceiverSmartCast
 import org.jetbrains.kotlin.idea.frontend.api.ImplicitReceiverSmartcastKind
@@ -20,18 +22,16 @@ import org.jetbrains.kotlin.psi.KtExpression
 internal class KtFirSmartcastProvider(
     override val analysisSession: KtFirAnalysisSession,
     override val token: ValidityToken,
-    ) : KtSmartCastProvider(), KtFirAnalysisSessionComponent {
-    override fun getSmartCastedToTypes(expression: KtExpression): Collection<KtType> = withValidityAssertion {
-        // TODO filter out not used smartcasts
+) : KtSmartCastProvider(), KtFirAnalysisSessionComponent {
+    override fun getSmartCastedToType(expression: KtExpression): KtType? = withValidityAssertion {
         expression.getOrBuildFirSafe<FirExpressionWithSmartcast>(analysisSession.firResolveState)
-            ?.typesFromSmartCast
-            ?.map { it.asKtType() }
-            ?: emptyList()
+            ?.typeRef
+            ?.coneTypeSafe<ConeKotlinType>()
+            ?.asKtType()
     }
 
     @OptIn(ExperimentalStdlibApi::class)
-    override fun getImplicitReceiverSmartCasts(expression: KtExpression): Collection<ImplicitReceiverSmartCast> = withValidityAssertion {
-        // TODO filter out not used smartcasts
+    override fun getImplicitReceiverSmartCast(expression: KtExpression): Collection<ImplicitReceiverSmartCast> = withValidityAssertion {
         val qualifiedExpression =
             expression.getOrBuildFirSafe<FirQualifiedAccessExpression>(analysisSession.firResolveState) ?: return emptyList()
         if (qualifiedExpression.dispatchReceiver !is FirExpressionWithSmartcast
@@ -40,13 +40,13 @@ internal class KtFirSmartcastProvider(
         buildList {
             (qualifiedExpression.dispatchReceiver as? FirExpressionWithSmartcast)?.let { smartCasted ->
                 ImplicitReceiverSmartCast(
-                    smartCasted.typesFromSmartCast.map { it.asKtType() },
+                    smartCasted.typeRef.coneTypeSafe<ConeKotlinType>()?.asKtType() ?: return@let null,
                     ImplicitReceiverSmartcastKind.DISPATCH
                 )
             }?.let(::add)
             (qualifiedExpression.extensionReceiver as? FirExpressionWithSmartcast)?.let { smartCasted ->
                 ImplicitReceiverSmartCast(
-                    smartCasted.typesFromSmartCast.map { it.asKtType() },
+                    smartCasted.typeRef.coneTypeSafe<ConeKotlinType>()?.asKtType() ?: return@let null,
                     ImplicitReceiverSmartcastKind.EXTENSION
                 )
             }?.let(::add)