Extract JetTestUtils.getLastCommentInFile()

JetNameSuggesterTest contains useful code for getting the last comment
of a file. Extract it to JetTestUtils.getLastCommentInFile() so other
tests can use it as well.

compiler/tests/org/jetbrains/jet/JetTestUtils.java

@@ -29,6 +29,7 @@ import com.intellij.openapi.util.ShutDownTracker;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.CharsetToolkit;
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiFileFactory;
 import com.intellij.psi.impl.PsiFileFactoryImpl;
@@ -64,6 +65,7 @@ import org.jetbrains.jet.lang.resolve.java.AnalyzerFacadeForJVM;
 import org.jetbrains.jet.lang.resolve.lazy.LazyResolveTestUtil;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
+import org.jetbrains.jet.lexer.JetTokens;
 import org.jetbrains.jet.plugin.JetLanguage;
 import org.jetbrains.jet.test.InnerTestClasses;
 import org.jetbrains.jet.test.TestMetadata;
@@ -527,6 +529,21 @@ public class JetTestUtils {
         return result.toString();
     }
 
+    public static String getLastCommentInFile(JetFile file) {
+        PsiElement lastChild = file.getLastChild();
+        assert lastChild != null;
+
+        if (lastChild.getNode().getElementType().equals(JetTokens.BLOCK_COMMENT)) {
+            String lastChildText = lastChild.getText();
+            return lastChildText.substring(2, lastChildText.length() - 2).trim();
+        }
+        else if (lastChild.getNode().getElementType().equals(JetTokens.EOL_COMMENT)) {
+            return lastChild.getText().substring(2).trim();
+        } else {
+            throw new AssertionError("Test file '" + file.getName() + "' should end in a comment; last node was: " + lastChild);
+        }
+    }
+
     public static void compileJavaFiles(@NotNull Collection<File> files, List<String> options) throws IOException {
         JavaCompiler javaCompiler = ToolProvider.getSystemJavaCompiler();
         DiagnosticCollector<JavaFileObject> diagnosticCollector = new DiagnosticCollector<JavaFileObject>();

idea/tests/org/jetbrains/jet/plugin/refactoring/nameSuggester/JetNameSuggesterTest.java

@@ -17,12 +17,11 @@
 package org.jetbrains.jet.plugin.refactoring.nameSuggester;
 
 import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.psi.PsiElement;
 import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.JetTestUtils;
 import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetFile;
-import org.jetbrains.jet.lexer.JetTokens;
 import org.jetbrains.jet.plugin.PluginTestCaseBase;
 import org.jetbrains.jet.plugin.refactoring.JetNameSuggester;
 import org.jetbrains.jet.plugin.refactoring.JetNameValidator;
@@ -76,18 +75,7 @@ public class JetNameSuggesterTest extends LightCodeInsightFixtureTestCase {
     private void doTest() {
         myFixture.configureByFile(getTestName(false) + ".kt");
         JetFile file = (JetFile) myFixture.getFile();
-        PsiElement lastChild = file.getLastChild();
+        final String expectedResultText = JetTestUtils.getLastCommentInFile(file);
-        assert lastChild != null;
-        String expectedResultText = null;
-        if (lastChild.getNode().getElementType().equals(JetTokens.BLOCK_COMMENT)) {
-            String lastChildText = lastChild.getText();
-            expectedResultText = lastChildText.substring(2, lastChildText.length() - 2).trim();
-        }
-        else if (lastChild.getNode().getElementType().equals(JetTokens.EOL_COMMENT)) {
-            expectedResultText = lastChild.getText().substring(2).trim();
-        }
-        assert expectedResultText != null;
-        final String finalExpectedResultText = expectedResultText;
         try {
             JetRefactoringUtil.selectExpression(myFixture.getEditor(), file, new JetRefactoringUtil.SelectExpressionCallback() {
                 @Override
@@ -95,7 +83,7 @@ public class JetNameSuggesterTest extends LightCodeInsightFixtureTestCase {
                     String[] names = JetNameSuggester.suggestNames(expression, JetNameValidator.getEmptyValidator(getProject()), "value");
                     Arrays.sort(names);
                     String result = StringUtil.join(names, "\n").trim();
-                    assertEquals(finalExpectedResultText, result);
+                    assertEquals(expectedResultText, result);
                 }
             });
         } catch (JetRefactoringUtil.IntroduceRefactoringException e) {