SimplifiableCallChainInspection: don't report if suspend function cannot be called correctly

#KT-23934 Fixed

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

@@ -68,7 +68,8 @@ abstract class AbstractCallChainChecker : AbstractKotlinInspection() {
         @NonNls val secondFqName: String,
         @NonNls val replacement: String,
         @NonNls val additionalArgument: String? = null,
-        val withNotNullAssertion: Boolean = false
+        val withNotNullAssertion: Boolean = false,
+        val enableSuspendFunctionCall: Boolean = true
     ) {
         private fun String.convertToShort() = takeLastWhile { it != '.' }
 

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

@@ -7,13 +7,17 @@ package org.jetbrains.kotlin.idea.inspections.collections
 
 import com.intellij.codeInspection.ProblemHighlightType
 import com.intellij.codeInspection.ProblemsHolder
+import org.jetbrains.kotlin.backend.common.descriptors.isSuspend
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.idea.KotlinBundle
 import org.jetbrains.kotlin.js.resolve.JsPlatformAnalyzerServices
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.KtCallExpression
+import org.jetbrains.kotlin.psi.psiUtil.anyDescendantOfType
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
 import org.jetbrains.kotlin.psi.qualifiedExpressionVisitor
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.types.typeUtil.builtIns
 import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 
@@ -36,6 +40,12 @@ class SimplifiableCallChainInspection : AbstractCallChainChecker() {
                         }
                     ) return@check false
                 }
+                if (!conversion.enableSuspendFunctionCall) {
+                    val isCallingSuspendFunction = firstResolvedCall.call.callElement.anyDescendantOfType<KtCallExpression> {
+                        it.getResolvedCall(context)?.resultingDescriptor?.isSuspend == true
+                    }
+                    if (isCallingSuspendFunction) return@check false
+                }
                 true
             } ?: return
 
@@ -99,8 +109,8 @@ class SimplifiableCallChainInspection : AbstractCallChainChecker() {
             Conversion("kotlin.text.filter", "kotlin.text.isNotEmpty", "any"),
             Conversion("kotlin.text.filter", "kotlin.text.isEmpty", "none"),
 
-            Conversion("kotlin.collections.map", "kotlin.collections.joinTo", "joinTo"),
-            Conversion("kotlin.collections.map", "kotlin.collections.joinToString", "joinToString"),
+            Conversion("kotlin.collections.map", "kotlin.collections.joinTo", "joinTo", enableSuspendFunctionCall = false),
+            Conversion("kotlin.collections.map", "kotlin.collections.joinToString", "joinToString", enableSuspendFunctionCall = false),
             Conversion("kotlin.collections.map", "kotlin.collections.filterNotNull", "mapNotNull"),
 
             Conversion("kotlin.collections.listOf", "kotlin.collections.filterNotNull", "listOfNotNull")

idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringWithSuspendFunctionCall.kt

@@ -0,0 +1,8 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+suspend fun mapString(input: String): String = ""
+
+suspend fun main() {
+    val x = listOf("1", "2", "3").<caret>map { mapString(it) }.joinToString()
+}

idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToWithSuspendFunctionCall.kt

@@ -0,0 +1,9 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+suspend fun mapString(input: String): String = ""
+
+suspend fun main() {
+    val sb = StringBuilder()
+    val x = listOf("1", "2", "3").<caret>map { mapString(it) }.joinTo(sb)
+}

idea/testData/inspectionsLocal/collections/simplifiableCallChain/mapNotNullWithSuspendFunctionCall.kt

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+suspend fun mapString(input: String): String? = ""
+
+suspend fun main() {
+    val x = listOf("1", "2", "3").<caret>map { mapString(it) }.filterNotNull()
+}

idea/testData/inspectionsLocal/collections/simplifiableCallChain/mapNotNullWithSuspendFunctionCall.kt.after

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+suspend fun mapString(input: String): String? = ""
+
+suspend fun main() {
+    val x = listOf("1", "2", "3").mapNotNull { mapString(it) }
+}

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

@@ -1897,11 +1897,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringWithReferenceFake.kt");
             }
 
+            @TestMetadata("joinToStringWithSuspendFunctionCall.kt")
+            public void testJoinToStringWithSuspendFunctionCall() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToStringWithSuspendFunctionCall.kt");
+            }
+
             @TestMetadata("joinToWithComment.kt")
             public void testJoinToWithComment() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToWithComment.kt");
             }
 
+            @TestMetadata("joinToWithSuspendFunctionCall.kt")
+            public void testJoinToWithSuspendFunctionCall() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/joinToWithSuspendFunctionCall.kt");
+            }
+
             @TestMetadata("listOfNotNull.kt")
             public void testListOfNotNull() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/listOfNotNull.kt");
@@ -1917,6 +1927,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/mapNotNull.kt");
             }
 
+            @TestMetadata("mapNotNullWithSuspendFunctionCall.kt")
+            public void testMapNotNullWithSuspendFunctionCall() throws Exception {
+                runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/mapNotNullWithSuspendFunctionCall.kt");
+            }
+
             @TestMetadata("mapWithReturn.kt")
             public void testMapWithReturn() throws Exception {
                 runTest("idea/testData/inspectionsLocal/collections/simplifiableCallChain/mapWithReturn.kt");