FIR IDE: API to resolve KtTypeReference to KtType

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

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.idea.frontend.api.ValidityTokenOwner
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtNamedClassOrObjectSymbol
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.idea.frontend.api.types.KtTypeNullability
+import org.jetbrains.kotlin.psi.KtTypeReference
 
 public abstract class KtTypeProvider : KtAnalysisSessionComponent() {
     public abstract val builtinTypes: KtBuiltinTypes
@@ -17,6 +18,8 @@ public abstract class KtTypeProvider : KtAnalysisSessionComponent() {
 
     public abstract fun buildSelfClassType(symbol: KtNamedClassOrObjectSymbol): KtType
 
+    public abstract fun getKtType(ktTypeReference: KtTypeReference): KtType
+
     public abstract fun withNullability(type: KtType, newNullability: KtTypeNullability): KtType
 }
 
@@ -38,6 +41,14 @@ public interface KtTypeProviderMixIn : KtAnalysisSessionMixIn {
     public fun KtNamedClassOrObjectSymbol.buildSelfClassType(): KtType =
         analysisSession.typeProvider.buildSelfClassType(this)
 
+    /**
+     * Resolve [KtTypeReference] and return corresponding [KtType] if resolved.
+     *
+     * This may raise an exception if the resolution ends up with an unexpected kind.
+     */
+    public fun KtTypeReference.getKtType(): KtType =
+        analysisSession.typeProvider.getKtType(this)
+
     public fun KtType.withNullability(newNullability: KtTypeNullability): KtType =
         analysisSession.typeProvider.withNullability(this, newNullability)
 }

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

@@ -7,9 +7,14 @@ package org.jetbrains.kotlin.idea.frontend.api.fir.components
 
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.typeContext
+import org.jetbrains.kotlin.fir.types.FirErrorTypeRef
+import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
 import org.jetbrains.kotlin.fir.types.withNullability
+import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFir
+import org.jetbrains.kotlin.idea.fir.low.level.api.api.getOrBuildFirOfType
 import org.jetbrains.kotlin.idea.frontend.api.components.KtBuiltinTypes
 import org.jetbrains.kotlin.idea.frontend.api.components.KtTypeProvider
 import org.jetbrains.kotlin.idea.frontend.api.fir.KtFirAnalysisSession
@@ -21,6 +26,8 @@ import org.jetbrains.kotlin.idea.frontend.api.symbols.KtNamedClassOrObjectSymbol
 import org.jetbrains.kotlin.idea.frontend.api.tokens.ValidityToken
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.idea.frontend.api.types.KtTypeNullability
+import org.jetbrains.kotlin.idea.frontend.api.withValidityAssertion
+import org.jetbrains.kotlin.psi.KtTypeReference
 
 internal class KtFirTypeProvider(
     override val analysisSession: KtFirAnalysisSession,
@@ -51,6 +58,10 @@ internal class KtFirTypeProvider(
         return type.asKtType()
     }
 
+    override fun getKtType(ktTypeReference: KtTypeReference): KtType = withValidityAssertion {
+        ktTypeReference.getOrBuildFirOfType<FirResolvedTypeRef>(firResolveState).coneType.asKtType()
+    }
+
     override fun withNullability(type: KtType, newNullability: KtTypeNullability): KtType {
         require(type is KtFirType)
         return type.coneType.withNullability(newNullability.toConeNullability(), rootModuleSession.typeContext).asKtType()