From d047db850f772f772f837d0a364d1be355326f32 Mon Sep 17 00:00:00 2001
From: Kirill Rakhman <kirill.rakhman@jetbrains.com>
Date: Mon, 29 Jan 2024 15:06:00 +0100
Subject: [PATCH] [FIR] Fix nullability of function type created from custom
 function type

#KT-64706 Fixed
---
 .../kotlin/fir/types/FunctionalTypeUtils.kt   |  2 +-
 ...leComposableParameterAcrossModules.fir.txt | 18 +++++++++++++
 ...ullableComposableParameterAcrossModules.kt | 25 +++++++++++++++++++
 ...reePluginBlackBoxCodegenTestGenerated.java |  6 +++++
 4 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.fir.txt
 create mode 100644 plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.kt

diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/FunctionalTypeUtils.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/FunctionalTypeUtils.kt
index e30dcd2d3e5..0010ebe33d8 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/FunctionalTypeUtils.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/FunctionalTypeUtils.kt
@@ -113,7 +113,7 @@ private fun ConeKotlinType.createFunctionTypeWithNewKind(session: FirSession, ki
     val functionTypeId = ClassId(kind.packageFqName, kind.numberedClassName(expandedType.typeArguments.size - 1))
     return functionTypeId.toLookupTag().constructClassType(
         expandedType.typeArguments,
-        isNullable = false,
+        isNullable = expandedType.isNullable,
         attributes = expandedType.attributes
     )
 }
diff --git a/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.fir.txt b/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.fir.txt
new file mode 100644
index 00000000000..f471c68b9ad
--- /dev/null
+++ b/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.fir.txt
@@ -0,0 +1,18 @@
+Module: a
+FILE: a.kt
+    public final fun RMenuItem(onClick: R|(() -> kotlin/Unit)?| = Null(null), trailing: R|@R|org/jetbrains/kotlin/fir/plugin/MyComposable|()  some/MyComposableFunction0<kotlin/Unit>?| = Null(null)): R|kotlin/Unit| {
+    }
+Module: b
+FILE: b.kt
+    public final fun bar(onClick: R|(() -> kotlin/Unit)?| = Null(null)): R|kotlin/Unit| {
+        R|/RMenuItem|(onClick = R|<local>/onClick|, trailing = R|<local>/onClick|?.{ $subj$.R|kotlin/let|<R|() -> kotlin/Unit|, R|@R|org/jetbrains/kotlin/fir/plugin/MyComposable|()  some/MyComposableFunction0<kotlin/Unit>?|>(<L> = let@fun <anonymous>(it: R|() -> kotlin/Unit|): R|@R|org/jetbrains/kotlin/fir/plugin/MyComposable|()  some/MyComposableFunction0<kotlin/Unit>?| <inline=Inline, kind=EXACTLY_ONCE>  {
+            ^ let@fun <anonymous>(): R|kotlin/Unit| <inline=Unknown>  {
+                ^@let Unit
+            }
+
+        }
+        ) })
+    }
+    public final fun box(): R|kotlin/String| {
+        ^box String(OK)
+    }
diff --git a/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.kt b/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.kt
new file mode 100644
index 00000000000..7511bd8416f
--- /dev/null
+++ b/plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.kt
@@ -0,0 +1,25 @@
+// ISSUE: KT-64994
+
+// MODULE: a
+// FILE: a.kt
+import org.jetbrains.kotlin.fir.plugin.MyComposable
+
+fun RMenuItem(
+    onClick: (() -> Unit)? = null,
+    trailing: (@MyComposable () -> Unit)? = null,
+) {}
+
+// MODULE: b(a)
+// FILE: b.kt
+import org.jetbrains.kotlin.fir.plugin.MyComposable
+
+fun bar(onClick: (() -> Unit)? = null) {
+    RMenuItem(
+        onClick = onClick,
+        trailing = onClick?.let {
+            { }
+        }
+    )
+}
+
+fun box() = "OK"
\ No newline at end of file
diff --git a/plugins/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/runners/FirLightTreePluginBlackBoxCodegenTestGenerated.java b/plugins/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/runners/FirLightTreePluginBlackBoxCodegenTestGenerated.java
index f709e6a248b..cf21cce9983 100644
--- a/plugins/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/runners/FirLightTreePluginBlackBoxCodegenTestGenerated.java
+++ b/plugins/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/runners/FirLightTreePluginBlackBoxCodegenTestGenerated.java
@@ -97,6 +97,12 @@ public class FirLightTreePluginBlackBoxCodegenTestGenerated extends AbstractFirL
         runTest("plugins/fir-plugin-prototype/testData/box/newSupertype.kt");
     }
 
+    @Test
+    @TestMetadata("nullableComposableParameterAcrossModules.kt")
+    public void testNullableComposableParameterAcrossModules() throws Exception {
+        runTest("plugins/fir-plugin-prototype/testData/box/nullableComposableParameterAcrossModules.kt");
+    }
+
     @Test
     @TestMetadata("replaceActualFunctionBodyWitExpectDefaultValue.kt")
     public void testReplaceActualFunctionBodyWitExpectDefaultValue() throws Exception {