From 9949de36c93071aef0701941b1bd202ce19a5c8a Mon Sep 17 00:00:00 2001
From: Kirill Rakhman <kirill.rakhman@jetbrains.com>
Date: Thu, 14 Sep 2023 09:54:07 +0200
Subject: [PATCH] [FIR] Fix false negative
 ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS

... in presence of typealiases.

#KT-61921
---
 .../ArrayEqualityCanBeReplacedWithEquals.fir.txt           | 7 +++++++
 .../ArrayEqualityCanBeReplacedWithEquals.kt                | 4 ++++
 .../extended/ArrayEqualityCanBeReplacedWithEquals.kt       | 6 +++---
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.fir.txt b/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.fir.txt
index ad6b5994878..23aa0c48f2f 100644
--- a/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.fir.txt
+++ b/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.fir.txt
@@ -1,12 +1,19 @@
 FILE: ArrayEqualityCanBeReplacedWithEquals.kt
+    public final typealias A<T> = R|kotlin/Array<T>|
     public final fun foo(p: R|kotlin/Int|): R|kotlin/Unit| {
         lval a: R|kotlin/Array<kotlin/Int>| = R|kotlin/arrayOf|<R|kotlin/Int|>(vararg(Int(1), Int(2), Int(3)))
         lval b: R|kotlin/Array<kotlin/Int>| = R|kotlin/arrayOf|<R|kotlin/Int|>(vararg(Int(3), Int(2), Int(1)))
+        lval c: R|A<kotlin/Int>| = R|kotlin/arrayOf|<R|kotlin/Int|>(vararg(Int(3), Int(2), Int(1)))
         when () {
             ==(R|<local>/a|, R|<local>/b|) ->  {
             }
         }
 
+        when () {
+            ==(R|<local>/a|, R|<local>/c|) ->  {
+            }
+        }
+
     }
     public final fun testsFromIdea(): R|kotlin/Unit| {
         lval a: R|kotlin/Array<kotlin/String>| = R|kotlin/arrayOf|<R|kotlin/String|>(vararg(String(a)))
diff --git a/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.kt b/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.kt
index b50f9364cef..dd2085d3090 100644
--- a/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.kt
+++ b/compiler/fir/analysis-tests/testData/resolve/extendedCheckers/ArrayEqualityCanBeReplacedWithEquals.kt
@@ -1,10 +1,14 @@
 // WITH_STDLIB
 
+typealias A<T> = Array<T>
+
 fun foo(p: Int) {
     val a = arrayOf(1, 2, 3)
     val b = arrayOf(3, 2, 1)
+    val c : A<Int> = arrayOf(3, 2, 1)
 
     if (a <!ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS!>==<!> b) { }
+    if (a <!ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS!>==<!> c) { }
 }
 
 fun testsFromIdea() {
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extended/ArrayEqualityCanBeReplacedWithEquals.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extended/ArrayEqualityCanBeReplacedWithEquals.kt
index 03d59853ab9..5bd476631fe 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extended/ArrayEqualityCanBeReplacedWithEquals.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extended/ArrayEqualityCanBeReplacedWithEquals.kt
@@ -14,7 +14,7 @@ import org.jetbrains.kotlin.fir.expressions.FirEqualityOperatorCall
 import org.jetbrains.kotlin.fir.expressions.FirOperation
 import org.jetbrains.kotlin.fir.expressions.FirStatement
 import org.jetbrains.kotlin.fir.expressions.arguments
-import org.jetbrains.kotlin.fir.types.classId
+import org.jetbrains.kotlin.fir.analysis.checkers.fullyExpandedClassId
 import org.jetbrains.kotlin.fir.types.resolvedType
 import org.jetbrains.kotlin.name.StandardClassIds
 
@@ -26,8 +26,8 @@ object ArrayEqualityCanBeReplacedWithEquals : FirBasicExpressionChecker() {
         val left = arguments.getOrNull(0) ?: return
         val right = arguments.getOrNull(1) ?: return
 
-        if (left.resolvedType.classId != StandardClassIds.Array) return
-        if (right.resolvedType.classId != StandardClassIds.Array) return
+        if (left.resolvedType.fullyExpandedClassId(context.session) != StandardClassIds.Array) return
+        if (right.resolvedType.fullyExpandedClassId(context.session) != StandardClassIds.Array) return
 
         reporter.reportOn(expression.source, ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS, context)
     }