extract light method object: complete array initializer with first element type (IDEA-131435)

(cherry picked from commit 2b66700cb40889d0578426a0ddca6fb0b02f2718)

java/java-impl/src/com/intellij/refactoring/extractMethodObject/ExtractLightMethodObjectHandler.java

@@ -73,12 +73,9 @@ public class ExtractLightMethodObjectHandler {
                                                        final PsiFile file,
                                                        @NotNull final PsiCodeFragment fragment,
                                                        final String methodName) throws PrepareFailedException {
-    PsiExpression expression = CodeInsightUtil.findExpressionInRange(fragment, 0, fragment.getTextLength());
     final PsiElementFactory elementFactory = JavaPsiFacade.getElementFactory(project);
-    final PsiElement[] elements;
-    if (expression != null) {
-      elements = new PsiElement[] {elementFactory.createStatementFromText(expression.getText() + ";", expression)};
-    } else {
+    PsiElement[] elements = completeToStatementArray(fragment, elementFactory);
+    if (elements == null) {
       elements = CodeInsightUtil.findStatementsInRange(fragment, 0, fragment.getTextLength());
     }
     if (elements.length == 0) {
@@ -213,6 +210,30 @@ public class ExtractLightMethodObjectHandler {
                              originalAnchor);
   }
 
+  @Nullable 
+  private static PsiElement[] completeToStatementArray(PsiCodeFragment fragment, PsiElementFactory elementFactory) {
+    PsiExpression expression = CodeInsightUtil.findExpressionInRange(fragment, 0, fragment.getTextLength());
+    if (expression != null) {
+      String completeExpressionText = null;
+      if (expression instanceof PsiArrayInitializerExpression) {
+        final PsiExpression[] initializers = ((PsiArrayInitializerExpression)expression).getInitializers();
+        if (initializers.length > 0) {
+          final PsiType type = initializers[0].getType();
+          if (type != null) {
+            completeExpressionText = "new " + type.getCanonicalText() + "[]" + expression.getText(); 
+          } 
+        }
+      } else {
+        completeExpressionText = expression.getText();
+      }
+
+      if (completeExpressionText != null) {
+        return new PsiElement[] {elementFactory.createStatementFromText(completeExpressionText + ";", expression)};
+      }
+    }
+    return null;
+  }
+
   private static boolean isValidVariableType(PsiType type) {
     if (type instanceof PsiClassType ||
         type instanceof PsiArrayType ||

java/java-tests/testData/refactoring/extractMethodObject4Debugger/ArrayInitializer.java

@@ -0,0 +1,5 @@
+class Sample {
+  void foo() {
+    Runnable[] runs = {<caret>};
+  }
+}

java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodObject4DebuggerTest.java

@@ -38,11 +38,19 @@ public class ExtractMethodObject4DebuggerTest extends LightRefactoringTestCase {
   }
 
   private void doTest(String evaluatedText, String expectedCallSite, String expectedClass) throws Exception {
+    doTest(evaluatedText, expectedCallSite, expectedClass, true);
+  }
+
+  private void doTest(String evaluatedText,
+                      String expectedCallSite,
+                      String expectedClass,
+                      boolean codeBlock) throws Exception {
     final String testName = getTestName(false);
     configureByFile("/refactoring/extractMethodObject4Debugger/" + testName + ".java");
     final int offset = getEditor().getCaretModel().getOffset();
     final PsiElement context = getFile().findElementAt(offset);
-    final JavaCodeFragment fragment = JavaCodeFragmentFactory.getInstance(getProject()).createCodeBlockCodeFragment(evaluatedText, context, false);
+    final JavaCodeFragmentFactory fragmentFactory = JavaCodeFragmentFactory.getInstance(getProject());
+    final JavaCodeFragment fragment = codeBlock ? fragmentFactory.createCodeBlockCodeFragment(evaluatedText, context, false) : fragmentFactory.createExpressionCodeFragment(evaluatedText, context, null, false);
     final ExtractLightMethodObjectHandler.ExtractedData extractedData =
       ExtractLightMethodObjectHandler.extractLightMethodObject(getProject(), getFile(), fragment, "test");
     assertNotNull(extractedData);
@@ -180,6 +188,19 @@ public class ExtractMethodObject4DebuggerTest extends LightRefactoringTestCase {
                                                "    }");
   }
 
+  public void testArrayInitializer() throws Exception {
+    doTest("{new Runnable() {public void run(){} } }", 
+           "Runnable[] result = new Test().invoke();",
+           "public class Test {\n" +
+           "        public Runnable[] invoke() {\n" +
+           "            return new Runnable[]{new Runnable() {\n" +
+           "                public void run() {\n" +
+           "                }\n" +
+           "            }};\n" +
+           "        }\n" +
+           "    }", false);
+  }
+
   @Override
   protected Sdk getProjectJDK() {
     return IdeaTestUtil.getMockJdk18();