[kotlin] KTIJ-34299 completion should not be stopped at the chain completion contributor

GitOrigin-RevId: 207583e0559b7263b26c0caf87a8acfaf4ca9133

plugins/kotlin/completion/impl-k2/src/org/jetbrains/kotlin/idea/completion/impl/k2/LookupElementSink.kt

@@ -41,6 +41,10 @@ internal class LookupElementSink(
     fun withContributorClass(contributorClass: Class<FirCompletionContributor<*>>): LookupElementSink =
         LookupElementSink(resultSet, parameters, groupPriority, contributorClass)
 
+    fun passResult(result: CompletionResult) {
+        resultSet.passResult(result)
+    }
+
     fun addElement(element: LookupElement) {
         decorateLookupElement(element)
             ?.let(resultSet::addElement)

plugins/kotlin/completion/impl-k2/src/org/jetbrains/kotlin/idea/completion/impl/k2/contributors/FirCompletionContributorBase.kt

@@ -193,23 +193,30 @@ internal abstract class FirCompletionContributorBase<C : KotlinRawPositionContex
 
         sink.runRemainingContributors(parameters.delegate) { completionResult ->
             val lookupElement = completionResult.lookupElement
-            val (_, importStrategy) = lookupElement.`object` as? ClassifierLookupObject
-                ?: return@runRemainingContributors
-
-            val nameToImport = when (importStrategy) {
+            val classifierLookupObject = lookupElement.`object` as? ClassifierLookupObject
+            val nameToImport = when (val importStrategy = classifierLookupObject?.importingStrategy) {
                 is ImportStrategy.AddImport -> importStrategy.nameToImport
                 is ImportStrategy.InsertFqNameAndShorten -> importStrategy.fqName
-                ImportStrategy.DoNothing -> null
-            } ?: return@runRemainingContributors
+                else -> null
+            }
+
+            if (nameToImport == null) {
+                sink.passResult(completionResult)
+                return@runRemainingContributors
+            }
 
             val expression = KtPsiFactory.contextual(explicitReceiver)
                 .createExpression(nameToImport.render() + "." + positionContext.nameExpression.text) as KtDotQualifiedExpression
 
             val receiverExpression = expression.receiverExpression as? KtDotQualifiedExpression
-                ?: return@runRemainingContributors
-
             val nameExpression = expression.selectorExpression as? KtNameReferenceExpression
-                ?: return@runRemainingContributors
+
+            if (receiverExpression == null
+                || nameExpression == null
+            ) {
+                sink.passResult(completionResult)
+                return@runRemainingContributors
+            }
 
             analyze(nameExpression) {
                 createLookupElements(

plugins/kotlin/completion/testData/basic/fullJdk/chain/ChainCompletionRemaining.kt

@@ -0,0 +1,8 @@
+// REGISTRY: kotlin.k2.chain.completion.enabled true
+
+fun main() {
+    "".val<caret>
+}
+
+// EXIST: { lookupString: ".val", itemText: "val" }
+// INVOCATION_COUNT: 0

plugins/kotlin/completion/testData/basic/fullJdk/chain/ChainedCallableCompletion.kt

@@ -4,5 +4,6 @@ fun main() {
     Collections.<caret>
 }
 
+// ABSENT: Collections
 // EXIST: { lookupString: "emptyList", itemText: "Collections.emptyList", tailText: "()", typeText: "kotlin.collections.(Mutable)List<T!>" }
 // INVOCATION_COUNT: 0

plugins/kotlin/completion/testData/basic/fullJdk/chain/ChainedClassifierCompletion.kt

@@ -4,5 +4,6 @@ fun main() {
     DirectoryStream.<caret>
 }
 
+// ABSENT: DirectoryStream
 // EXIST: { lookupString: "Filter", itemText: "DirectoryStream.Filter", tailText: "<T> (java.nio.file.DirectoryStream)" }
 // INVOCATION_COUNT: 0

plugins/kotlin/fir/tests/test/org/jetbrains/kotlin/idea/fir/completion/K2JvmBasicCompletionFullJdkTestGenerated.java

@@ -33,6 +33,11 @@ public abstract class K2JvmBasicCompletionFullJdkTestGenerated extends AbstractK
             KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
         }
 
+        @TestMetadata("ChainCompletionRemaining.kt")
+        public void testChainCompletionRemaining() throws Exception {
+            runTest("../../completion/testData/basic/fullJdk/chain/ChainCompletionRemaining.kt");
+        }
+
         @TestMetadata("ChainedCallableCompletion.kt")
         public void testChainedCallableCompletion() throws Exception {
             runTest("../../completion/testData/basic/fullJdk/chain/ChainedCallableCompletion.kt");

plugins/kotlin/plugin/k2/resources/kotlin.plugin.k2.xml

@@ -116,7 +116,7 @@
                             implementationClass="org.jetbrains.kotlin.idea.completion.KotlinFirCompletionContributor"/>
 
     <completion.contributor language="kotlin"
-                            order="first, after KotlinDumbCompletionContributor"
+                            order="last, before default"
                             implementationClass="org.jetbrains.kotlin.idea.completion.impl.k2.KotlinChainCompletionContributor"/>
 
     <registryKey key="kotlin.k2.chain.completion.enabled"