From f2cddf72019fa7225ea953959bfded3c460e121d Mon Sep 17 00:00:00 2001
From: Anna Kozlova <anna.kozlova@jetbrains.com>
Date: Wed, 17 Jun 2015 19:05:20 +0300
Subject: [PATCH] extract method: don't skip vars from the exit statements if
 nullable checks would be added (IDEA-141562)

---
 .../extractMethod/ControlFlowWrapper.java     | 16 ++++++++++----
 .../extractMethod/ExtractMethodProcessor.java |  4 ++--
 ...houldPreserveVarsUsedInExitStatements.java | 12 +++++++++++
 ...reserveVarsUsedInExitStatements_after.java | 21 +++++++++++++++++++
 .../GuardMethodDuplicates1_after.java         |  1 -
 .../refactoring/ExtractMethodTest.java        |  4 ++++
 6 files changed, 51 insertions(+), 7 deletions(-)
 create mode 100644 java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements.java
 create mode 100644 java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements_after.java

diff --git a/java/java-impl/src/com/intellij/refactoring/extractMethod/ControlFlowWrapper.java b/java/java-impl/src/com/intellij/refactoring/extractMethod/ControlFlowWrapper.java
index eb16437e6a33..11df15fbd9ac 100644
--- a/java/java-impl/src/com/intellij/refactoring/extractMethod/ControlFlowWrapper.java
+++ b/java/java-impl/src/com/intellij/refactoring/extractMethod/ControlFlowWrapper.java
@@ -242,10 +242,10 @@ public class ControlFlowWrapper {
     return true;
   }
 
-  public List<PsiVariable> getInputVariables(final PsiElement codeFragment, PsiElement[] elements) {
+  public List<PsiVariable> getInputVariables(final PsiElement codeFragment, PsiElement[] elements, PsiVariable[] outputVariables) {
     final List<PsiVariable> inputVariables = ControlFlowUtil.getInputVariables(myControlFlow, myFlowStart, myFlowEnd);
     List<PsiVariable> myInputVariables;
-    if (myGenerateConditionalExit) {
+    if (skipVariablesFromExitStatements(outputVariables)) {
       List<PsiVariable> inputVariableList = new ArrayList<PsiVariable>(inputVariables);
       removeParametersUsedInExitsOnly(codeFragment, inputVariableList);
       myInputVariables = inputVariableList;
@@ -341,8 +341,16 @@ public class ControlFlowWrapper {
     return getUsedVariables(myFlowEnd);
   }
 
-  public List<PsiVariable> getUsedVariablesInBody() {
-    return getUsedVariables(myFlowStart, myFlowEnd);
+  public List<PsiVariable> getUsedVariablesInBody(PsiElement codeFragment, PsiVariable[] outputVariables) {
+    final List<PsiVariable> variables = getUsedVariables(myFlowStart, myFlowEnd);
+    if (skipVariablesFromExitStatements(outputVariables)) {
+      removeParametersUsedInExitsOnly(codeFragment, variables);
+    }
+    return variables;
+  }
+
+  private boolean skipVariablesFromExitStatements(PsiVariable[] outputVariables) {
+    return myGenerateConditionalExit && outputVariables.length == 0;
   }
 
   public Collection<ControlFlowUtil.VariableInfo> getInitializedTwice() {
diff --git a/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java b/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java
index 987e7157303c..61fb8703159d 100644
--- a/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java
+++ b/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java
@@ -1438,7 +1438,7 @@ public class ExtractMethodProcessor implements MatchProvider {
   }
 
   private boolean chooseTargetClass(PsiElement codeFragment, final Pass<ExtractMethodProcessor> extractPass) throws PrepareFailedException {
-    final List<PsiVariable> inputVariables = myControlFlowWrapper.getInputVariables(codeFragment, myElements);
+    final List<PsiVariable> inputVariables = myControlFlowWrapper.getInputVariables(codeFragment, myElements, myOutputVariables);
 
     myNeedChangeContext = false;
     myTargetClass = myCodeFragmentMember instanceof PsiMember
@@ -1513,7 +1513,7 @@ public class ExtractMethodProcessor implements MatchProvider {
   }
 
   private void declareNecessaryVariablesInsideBody(PsiCodeBlock body) throws IncorrectOperationException {
-    List<PsiVariable> usedVariables = myControlFlowWrapper.getUsedVariablesInBody();
+    List<PsiVariable> usedVariables = myControlFlowWrapper.getUsedVariablesInBody(ControlFlowUtil.findCodeFragment(myElements[0]), myOutputVariables);
     for (PsiVariable variable : usedVariables) {
       boolean toDeclare = !isDeclaredInside(variable) && myInputVariables.toDeclareInsideBody(variable);
       if (toDeclare) {
diff --git a/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements.java b/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements.java
new file mode 100644
index 000000000000..831178c21123
--- /dev/null
+++ b/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements.java
@@ -0,0 +1,12 @@
+class X {
+  static String guessTestDataName(String method, String testName, String[] methods) {
+    for (String psiMethod : methods) {
+      <selection>String strings = method;
+      if (strings != null && !strings.isEmpty()) {
+        return strings.substring(0) + testName;
+      }
+      </selection>
+    }
+    return null;
+  }
+}
diff --git a/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements_after.java b/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements_after.java
new file mode 100644
index 000000000000..db3cef1ba79d
--- /dev/null
+++ b/java/java-tests/testData/refactoring/extractMethod/ConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements_after.java
@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+
+class X {
+  static String guessTestDataName(String method, String testName, String[] methods) {
+    for (String psiMethod : methods) {
+        String strings = newMethod(method, testName);
+        if (strings != null) return strings;
+      
+    }
+    return null;
+  }
+
+    @Nullable
+    private static String newMethod(String method, String testName) {
+        String strings = method;
+        if (strings != null && !strings.isEmpty()) {
+          return strings.substring(0) + testName;
+        }
+        return null;
+    }
+}
diff --git a/java/java-tests/testData/refactoring/extractMethod/GuardMethodDuplicates1_after.java b/java/java-tests/testData/refactoring/extractMethod/GuardMethodDuplicates1_after.java
index 6ad32250004a..37d1a9bdcca9 100644
--- a/java/java-tests/testData/refactoring/extractMethod/GuardMethodDuplicates1_after.java
+++ b/java/java-tests/testData/refactoring/extractMethod/GuardMethodDuplicates1_after.java
@@ -7,7 +7,6 @@ public class Test {
     }
 
     private boolean newMethod() {
-        Object result;
         if (test1()) return true;
         if (test2()) return true;
         return false;
diff --git a/java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java b/java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java
index cad137eae2ab..6a232ae4b830 100644
--- a/java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java
+++ b/java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java
@@ -749,6 +749,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     }
   }
 
+  public void testConditionalExitCombinedWithNullabilityShouldPreserveVarsUsedInExitStatements() throws Exception {
+    doTest();
+  }
+
   private void doTestDisabledParam() throws PrepareFailedException {
     final CodeStyleSettings settings = CodeStyleSettingsManager.getSettings(getProject());
     settings.ELSE_ON_NEW_LINE = true;