[FIR] ASSIGNING_SINGLE_ELEMENT_TO_VARARG_IN_NAMED_FORM_FUNCTION diag

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -1332,6 +1332,20 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.ASSIGNING_SINGLE_ELEMENT_TO_VARARG_IN_NAMED_FORM_FUNCTION.errorFactory) { firDiagnostic ->
+        AssigningSingleElementToVarargInNamedFormFunctionErrorImpl(
+            firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),
+            firDiagnostic as FirPsiDiagnostic,
+            token,
+        )
+    }
+    add(FirErrors.ASSIGNING_SINGLE_ELEMENT_TO_VARARG_IN_NAMED_FORM_FUNCTION.warningFactory) { firDiagnostic ->
+        AssigningSingleElementToVarargInNamedFormFunctionWarningImpl(
+            firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),
+            firDiagnostic as FirPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.OVERLOAD_RESOLUTION_AMBIGUITY) { firDiagnostic ->
         OverloadResolutionAmbiguityImpl(
             firDiagnostic.a.map { firBasedSymbol ->

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -956,6 +956,16 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = SpreadOfNullable::class
     }
 
+    abstract class AssigningSingleElementToVarargInNamedFormFunctionError : KtFirDiagnostic<KtExpression>() {
+        override val diagnosticClass get() = AssigningSingleElementToVarargInNamedFormFunctionError::class
+        abstract val type: KtType
+    }
+
+    abstract class AssigningSingleElementToVarargInNamedFormFunctionWarning : KtFirDiagnostic<KtExpression>() {
+        override val diagnosticClass get() = AssigningSingleElementToVarargInNamedFormFunctionWarning::class
+        abstract val type: KtType
+    }
+
     abstract class OverloadResolutionAmbiguity : KtFirDiagnostic<PsiElement>() {
         override val diagnosticClass get() = OverloadResolutionAmbiguity::class
         abstract val candidates: List<KtSymbol>

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -1527,6 +1527,22 @@ internal class SpreadOfNullableImpl(
     override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
 }
 
+internal class AssigningSingleElementToVarargInNamedFormFunctionErrorImpl(
+    override val type: KtType,
+    firDiagnostic: FirPsiDiagnostic,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.AssigningSingleElementToVarargInNamedFormFunctionError(), KtAbstractFirDiagnostic<KtExpression> {
+    override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
+}
+
+internal class AssigningSingleElementToVarargInNamedFormFunctionWarningImpl(
+    override val type: KtType,
+    firDiagnostic: FirPsiDiagnostic,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.AssigningSingleElementToVarargInNamedFormFunctionWarning(), KtAbstractFirDiagnostic<KtExpression> {
+    override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
+}
+
 internal class OverloadResolutionAmbiguityImpl(
     override val candidates: List<KtSymbol>,
     firDiagnostic: FirPsiDiagnostic,