flatMap call could be simplified to flatten(): Fix false positive with Array

#KT-33204 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/collections/SimplifiableCallInspection.kt

@@ -11,8 +11,10 @@ import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.codeInspection.ProblemsHolder
 import com.intellij.openapi.project.Project
 import org.jetbrains.kotlin.KtNodeTypes
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToCall
+import org.jetbrains.kotlin.idea.debugger.sequence.psi.receiverType
 import org.jetbrains.kotlin.idea.inspections.AbstractKotlinInspection
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.name.FqName
@@ -87,6 +89,11 @@ class SimplifiableCallInspection : AbstractKotlinInspection() {
                 val reference = lambdaExpression.singleStatement() ?: return null
                 val lambdaParameterName = lambdaExpression.singleLambdaParameterName() ?: return null
                 if (!reference.isNameReferenceTo(lambdaParameterName)) return null
+                val receiverType = callExpression.receiverType() ?: return null
+                if (KotlinBuiltIns.isPrimitiveArray(receiverType)) return null
+                if (KotlinBuiltIns.isArray(receiverType)
+                    && receiverType.arguments.firstOrNull()?.type?.let { KotlinBuiltIns.isArray(it) } != true
+                ) return null
                 return "flatten()"
             }),
 

idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap.kt

@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun test() {
+    arrayOf(listOf(1), listOf(2)).flatMap<caret> { it }
+}

idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap2.kt

@@ -0,0 +1,5 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun Array<List<Int>>.test() {
+    <caret>flatMap { it }
+}

idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap3.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test() {
+    arrayOf(arrayOf(1, 2), arrayOf(3)).flatMap<caret> { it }
+}

idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap3.kt.after

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test() {
+    arrayOf(arrayOf(1, 2), arrayOf(3)).flatten()
+}

idea/testData/inspectionsLocal/collections/simplifiableCall/primitiveArrayFlatMap.kt

@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+// DISABLE-ERRORS
+fun test() {
+    intArrayOf(1, 2).flatMap<caret> { it }
+}

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -1472,6 +1472,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/inspectionsLocal/collections/simplifiableCall"), Pattern.compile("^([\\w\\-_]+)\\.(kt|kts)$"), TargetBackend.ANY, true);
             }
 
+            @TestMetadata("arrayFlatMap.kt")
+            public void testArrayFlatMap() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap.kt");
+            }
+
+            @TestMetadata("arrayFlatMap2.kt")
+            public void testArrayFlatMap2() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap2.kt");
+            }
+
+            @TestMetadata("arrayFlatMap3.kt")
+            public void testArrayFlatMap3() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/arrayFlatMap3.kt");
+            }
+
             @TestMetadata("explicitLambdaParameter.kt")
             public void testExplicitLambdaParameter() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/explicitLambdaParameter.kt");
@@ -1547,6 +1562,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/notOnlyReference.kt");
             }
 
+            @TestMetadata("primitiveArrayFlatMap.kt")
+            public void testPrimitiveArrayFlatMap() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/primitiveArrayFlatMap.kt");
+            }
+
             @TestMetadata("set.kt")
             public void testSet() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCall/set.kt");