KT-8979 Completion of non-imported extension with "!" character corrupts code

#KT-8979 Fixed

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/handlers/WithExpressionPrefixInsertHandler.kt

@@ -34,7 +34,9 @@ class WithExpressionPrefixInsertHandler(val prefix: String) : InsertHandler<Look
     }
 
     fun postHandleInsert(context: InsertionContext) {
-        PsiDocumentManager.getInstance(context.getProject()).commitAllDocuments()
+        val psiDocumentManager = PsiDocumentManager.getInstance(context.project)
+        psiDocumentManager.doPostponedOperationsAndUnblockDocument(context.document)
+        psiDocumentManager.commitAllDocuments()
 
         val offset = context.getStartOffset()
         val token = context.getFile().findElementAt(offset)!!

idea/idea-completion/testData/handlers/multifile/ExclCharInsertImport-1.kt

@@ -0,0 +1,8 @@
+package qqqq
+
+import a
+import b
+
+fun foo() {
+    "".isX<caret>
+}

idea/idea-completion/testData/handlers/multifile/ExclCharInsertImport-2.kt

@@ -0,0 +1,4 @@
+package foo
+
+val String.isXXX: Boolean
+    get() = true

idea/idea-completion/testData/handlers/multifile/ExclCharInsertImport.kt.after

@@ -0,0 +1,9 @@
+package qqqq
+
+import a
+import b
+import foo.isXXX
+
+fun foo() {
+    !"".isXXX<caret>
+}

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/CompletionMultifileHandlerTest.java

@@ -1,94 +0,0 @@
-/*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.idea.completion.test.handlers;
-
-import junit.framework.TestCase;
-import org.jetbrains.kotlin.idea.completion.test.KotlinCompletionTestCase;
-import org.jetbrains.kotlin.idea.completion.test.TestPackage;
-
-import java.io.File;
-
-public class CompletionMultifileHandlerTest extends KotlinCompletionTestCase {
-    public void testExtensionFunctionImport() throws Exception {
-        doTest();
-    }
-
-    public void testExtensionPropertyImport() throws Exception {
-        doTest();
-    }
-
-    public void testImportAlreadyImportedObject() throws Exception {
-        doTest();
-    }
-
-    public void testJetClassCompletionImport() throws Exception {
-        doTest();
-    }
-
-    public void testTopLevelFunctionImport() throws Exception {
-        doTest();
-    }
-
-    public void testTopLevelFunctionInQualifiedExpr() throws Exception {
-        doTest();
-    }
-
-    public void testTopLevelPropertyImport() throws Exception {
-        doTest();
-    }
-
-    public void testNoParenthesisInImports() throws Exception {
-        doTest();
-    }
-
-    public void testKeywordExtensionFunctionName() throws Exception {
-        doTest();
-    }
-
-    public void testInfixExtensionCallImport() throws Exception {
-        doTest();
-    }
-
-    public void testClassWithClassObject() throws Exception {
-        doTest();
-    }
-
-    public void testGlobalFunctionImportInLambda() throws Exception {
-        doTest();
-    }
-
-    public void testObjectInStringTemplate() throws Exception {
-        doTest();
-    }
-
-    public void doTest() throws Exception {
-        String fileName = getTestName(false);
-
-        configureByFiles(null, fileName + "-1.kt", fileName + "-2.kt");
-        complete(2);
-        if (myItems != null) {
-            TestCase.assertTrue("Multiple items in completion", myItems.length == 1);
-            selectItem(myItems[0]);
-        }
-        checkResultByFile(fileName + ".kt.after");
-    }
-
-    @Override
-    protected String getTestDataPath() {
-        return new File(TestPackage.getCOMPLETION_TEST_DATA_BASE_PATH(), "/handlers/multifile/").getPath() + File.separator;
-    }
-}

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/CompletionMultifileHandlerTest.kt

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.completion.test.handlers
+
+import org.jetbrains.kotlin.idea.completion.test.COMPLETION_TEST_DATA_BASE_PATH
+import org.jetbrains.kotlin.idea.completion.test.KotlinCompletionTestCase
+import java.io.File
+
+class CompletionMultiFileHandlerTest : KotlinCompletionTestCase() {
+    fun testExtensionFunctionImport() {
+        doTest()
+    }
+
+    fun testExtensionPropertyImport() {
+        doTest()
+    }
+
+    fun testImportAlreadyImportedObject() {
+        doTest()
+    }
+
+    fun testJetClassCompletionImport() {
+        doTest()
+    }
+
+    fun testTopLevelFunctionImport() {
+        doTest()
+    }
+
+    fun testTopLevelFunctionInQualifiedExpr() {
+        doTest()
+    }
+
+    fun testTopLevelPropertyImport() {
+        doTest()
+    }
+
+    fun testNoParenthesisInImports() {
+        doTest()
+    }
+
+    fun testKeywordExtensionFunctionName() {
+        doTest()
+    }
+
+    fun testInfixExtensionCallImport() {
+        doTest()
+    }
+
+    fun testClassWithClassObject() {
+        doTest()
+    }
+
+    fun testGlobalFunctionImportInLambda() {
+        doTest()
+    }
+
+    fun testObjectInStringTemplate() {
+        doTest()
+    }
+
+    fun testExclCharInsertImport() {
+        doTest('!')
+    }
+
+    fun doTest(completionChar: Char = '\n') {
+        val fileName = getTestName(false)
+
+        configureByFiles(null, fileName + "-1.kt", fileName + "-2.kt")
+        complete(2)
+        if (myItems != null) {
+            val item = myItems.singleOrNull() ?: error("Multiple items in completion")
+            selectItem(item, completionChar)
+        }
+        checkResultByFile(fileName + ".kt.after")
+    }
+
+    override fun getTestDataPath() = File(COMPLETION_TEST_DATA_BASE_PATH, "/handlers/multifile/").path + File.separator
+}