"Redundant 'requireNotNull' or 'checkNotNull' call": don't remove first argument if function is used as expression

#KT-31404 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/RedundantRequireNotNullCallInspection.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
 import org.jetbrains.kotlin.psi.psiUtil.referenceExpression
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.bindingContextUtil.getDataFlowInfoBefore
+import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsExpression
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
@@ -68,7 +69,12 @@ private class RemoveRequireNotNullCallFix(private val functionName: String) : Lo
 
     override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
         val callExpression = descriptor.psiElement.getStrictParentOfType<KtCallExpression>() ?: return
-        val qualifiedExpression = callExpression.getQualifiedExpressionForSelector()
-        (qualifiedExpression ?: callExpression).delete()
+        val argument = callExpression.valueArguments.firstOrNull()?.getArgumentExpression() ?: return
+        val target = callExpression.getQualifiedExpressionForSelector() ?: callExpression
+        if (callExpression.isUsedAsExpression(callExpression.analyze(BodyResolveMode.PARTIAL))) {
+            target.replace(argument)            
+        } else {
+            target.delete()
+        }
     }
 }

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    val a = <caret>requireNotNull(i)
+}

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression.kt.after

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    val a = i
+}

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression2.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    println(<caret>requireNotNull(i) { "" })
+}

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression2.kt.after

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    println(i)
+}

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression3.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    "${<caret>checkNotNull(i)}"
+}

idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression3.kt.after

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test(i: Int) {
+    "${i}"
+}

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

@@ -5779,6 +5779,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         public void testRequire() throws Exception {
             runTest("idea/testData/inspectionsLocal/redundantRequireNotNullCall/require.kt");
         }
+
+        @TestMetadata("usedAsExpression.kt")
+        public void testUsedAsExpression() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression.kt");
+        }
+
+        @TestMetadata("usedAsExpression2.kt")
+        public void testUsedAsExpression2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression2.kt");
+        }
+
+        @TestMetadata("usedAsExpression3.kt")
+        public void testUsedAsExpression3() throws Exception {
+            runTest("idea/testData/inspectionsLocal/redundantRequireNotNullCall/usedAsExpression3.kt");
+        }
     }
 
     @TestMetadata("idea/testData/inspectionsLocal/redundantReturnLabel")