Introduce Variable: Do not suggest expressions without type

#KT-12922 Fixed

ChangeLog.md

@@ -241,6 +241,7 @@ Using 'this' as function argument in constructor of non-final class
 - [`KT-13082`](https://youtrack.jetbrains.com/issue/KT-13082) Rename: Fix exception on property rename preview
 - [`KT-13207`](https://youtrack.jetbrains.com/issue/KT-13207) Safe delete: Fix exception when removing any function in 2016.2
 - [`KT-12945`](https://youtrack.jetbrains.com/issue/KT-12945) Rename: Fix function description in super method warning dialog
+- [`KT-12922`](https://youtrack.jetbrains.com/issue/KT-12922) Introduce Variable: Do not suggest expressions without type
 
 ##### New features
 

idea/src/org/jetbrains/kotlin/idea/refactoring/KotlinRefactoringUtil.java

@@ -431,7 +431,7 @@ public class KotlinRefactoringUtil {
                         KtExpression expression = (KtExpression)element;
                         BindingContext bindingContext = ResolutionUtils.analyze(expression, BodyResolveMode.FULL);
                         KotlinType expressionType = bindingContext.getType(expression);
-                        if (expressionType != null && KotlinBuiltIns.isUnit(expressionType)) {
+                        if (expressionType == null || KotlinBuiltIns.isUnit(expressionType)) {
                             addElement = false;
                         }
                     }

idea/testData/refactoring/introduceVariable/skipClassReference.kt

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+import java.util.*
+
+fun foo() {
+    <caret>Arrays.asList(1, 2, 3)
+}

idea/testData/refactoring/introduceVariable/skipClassReference.kt.after

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+import java.util.*
+
+fun foo() {
+    val asList = Arrays.asList(1, 2, 3)
+}

idea/testData/smartSelection/simple.kt

@@ -5,5 +5,4 @@ fun main(args: Array<String>) {
 1.0
 1.0 + 1
 Math.pow(...)
-print(...)
 */

idea/tests/org/jetbrains/kotlin/idea/refactoring/introduce/ExtractionTestGenerated.java

@@ -373,6 +373,12 @@ public class ExtractionTestGenerated extends AbstractExtractionTest {
             doIntroduceVariableTest(fileName);
         }
 
+        @TestMetadata("skipClassReference.kt")
+        public void testSkipClassReference() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/introduceVariable/skipClassReference.kt");
+            doIntroduceVariableTest(fileName);
+        }
+
         @TestMetadata("StringInjection.kt")
         public void testStringInjection() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/refactoring/introduceVariable/StringInjection.kt");