Call chain into sequence: fix false negative on Iterable

#KT-26650 Fixed

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

@@ -154,7 +154,7 @@ private fun KtQualifiedExpression.findCallChain(): CallChain? {
     val receiverType =
         (lastCall.getQualifiedExpressionForSelector())?.receiverExpression?.getResolvedCall(context)?.resultingDescriptor?.returnType
             ?: lastCall.implicitReceiver(context)?.type
-    if (receiverType?.isCollection() != true) return null
+    if (receiverType?.isMap(DefaultBuiltIns.Instance) == true) return null
 
     val firstCall = calls.first()
     val qualified = firstCall.getQualifiedExpressionForSelector() ?: firstCall.getQualifiedExpressionForReceiver() ?: return null
@@ -193,14 +193,6 @@ private fun KtExpression.implicitReceiver(context: BindingContext): ImplicitRece
     return getResolvedCall(context)?.getImplicitReceiverValue()
 }
 
-private fun KotlinType.isCollection(): Boolean {
-    val classDescriptor = constructor.declarationDescriptor as? ClassDescriptor ?: return false
-    val className = classDescriptor.name.asString()
-    val builtIns = DefaultBuiltIns.Instance
-    return className.endsWith("List") && classDescriptor.isSubclassOf(builtIns.list)
-            || className.endsWith("Set") && classDescriptor.isSubclassOf(builtIns.set)
-}
-
 private fun KtCallExpression.hasReturn(): Boolean = valueArguments.any { arg ->
     arg.anyDescendantOfType<KtReturnExpression> { it.labelQualifier == null }
 }

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

@@ -16,14 +16,22 @@
 
 package org.jetbrains.kotlin.idea.inspections.collections
 
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.getFunctionalClassKind
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.callUtil.getType
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.descriptorUtil.isSubclassOf
 import org.jetbrains.kotlin.types.KotlinType
 
 fun KotlinType.isFunctionOfAnyKind() = constructor.declarationDescriptor?.getFunctionalClassKind() != null
 
+fun KotlinType?.isMap(builtIns: KotlinBuiltIns): Boolean {
+    val classDescriptor = this?.constructor?.declarationDescriptor as? ClassDescriptor ?: return false
+    return classDescriptor.name.asString().endsWith("Map") && classDescriptor.isSubclassOf(builtIns.map)
+}
+
 fun ResolvedCall<*>.hasLastFunctionalParameterWithResult(context: BindingContext, predicate: (KotlinType) -> Boolean): Boolean {
     val lastParameter = resultingDescriptor.valueParameters.lastOrNull() ?: return false
     val lastArgument = valueArguments[lastParameter]?.arguments?.singleOrNull() ?: return false

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

@@ -82,9 +82,4 @@ class SimplifiableCallChainInspection : AbstractCallChainChecker() {
             Conversion("kotlin.collections.listOf", "kotlin.collections.filterNotNull", "listOfNotNull")
         )
     }
-}
-
-private fun KotlinType?.isMap(builtIns: KotlinBuiltIns): Boolean {
-    val classDescriptor = this?.constructor?.declarationDescriptor as? ClassDescriptor ?: return false
-    return classDescriptor.name.asString().endsWith("Map") && classDescriptor.isSubclassOf(builtIns.map)
-}
+}

idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable.kt

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun test(i: Iterable<Int>): List<Int> {
+    return i.<caret>filter { it > 1 }.map { it * 2 }
+}

idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable.kt.after

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+fun test(i: Iterable<Int>): List<Int> {
+    return i.asSequence().filter { it > 1 }.map { it * 2 }.toList()
+}

idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable2.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+class A<T>(private val list: List<T>) : Iterable<T> {
+    override fun iterator(): Iterator<T> = list.iterator()
+}
+
+fun test(i: A<Int>): List<Int> {
+    return i.<caret>filter { it > 1 }.map { it * 2 }
+}

idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable2.kt.after

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+class A<T>(private val list: List<T>) : Iterable<T> {
+    override fun iterator(): Iterator<T> = list.iterator()
+}
+
+fun test(i: A<Int>): List<Int> {
+    return i.asSequence().filter { it > 1 }.map { it * 2 }.toList()
+}

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

@@ -574,6 +574,16 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/implicitReceiver.kt");
             }
 
+            @TestMetadata("iterable.kt")
+            public void testIterable() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable.kt");
+            }
+
+            @TestMetadata("iterable2.kt")
+            public void testIterable2() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/iterable2.kt");
+            }
+
             @TestMetadata("mutableList.kt")
             public void testMutableList() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/convertCallChainIntoSequence/mutableList.kt");