Remove locals moved via extract method if they aren't used elsewhere (#…

…1399)

- modify ExtractMethodRefactoring.createMethodBody() to check all
  locals that needed to be created in new method to see if the old
  declaration is still needed (i.e. referenced outside of the
  selected statements) and if not, remove the original declaration
- modify all ExtractMethodTests where the locals are left behind
  and not used elsewhere
- add new tests to ExtractMethodTests
- fixes #1357

org.eclipse.jdt.core.manipulation/refactoring/org/eclipse/jdt/internal/corext/refactoring/code/ExtractMethodRefactoring.java

@@ -1286,9 +1286,28 @@ private Block createMethodBody(ASTNode[] selectedNodes, TextEditGroup substitute
 
 		// Locals that are not passed as an arguments since the extracted method only
 		// writes to them
+		IRegion selectedNodeRange= fAnalyzer.getSelectedNodeRange();
+		int endOfSelectedNodes= selectedNodeRange.getOffset() + selectedNodeRange.getLength();
 		for (IVariableBinding methodLocal : fAnalyzer.getMethodLocals()) {
 			if (methodLocal != null) {
 				result.statements().add(createDeclaration(methodLocal, null));
+				// check if local variable that is used in selected nodes is also used outside of selected nodes, otherwise remove
+				SimpleName[] nodes= LinkedNodeFinder.findByBinding(fAnalyzer.getEnclosingBodyDeclaration(), methodLocal);
+				SimpleName firstNode= nodes[0];
+				VariableDeclarationStatement vdecl= ASTNodes.getFirstAncestorOrNull(firstNode, VariableDeclarationStatement.class);
+				if (vdecl != null) {
+					boolean needed= false;
+					for (int i= 1; i < nodes.length; ++i) {
+						SimpleName refNode= nodes[i];
+						if (refNode.getStartPosition() < selectedNodeRange.getOffset() || refNode.getStartPosition() > endOfSelectedNodes) {
+							needed= true;
+							break;
+						}
+					}
+					if (!needed) {
+						fRewriter.remove(vdecl, null);
+					}
+				}
 			}
 		}
 		for (ParameterInfo parameter : fParameterInfos) {

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/locals_out/A_test501.java

@@ -2,8 +2,6 @@
 
 public class A_test501 {
 	public void foo() {
-		int x= 10;
-
 		extracted();
 	}
 

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/locals_out/A_test502.java

@@ -2,9 +2,6 @@
 
 public class A_test502 {
 	public void foo() {
-		int x= 0;
-		int y= 0;
-
 		extracted();		
 	}
 

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/locals_out/A_test509.java

@@ -3,8 +3,6 @@
 public class A_test509 {
 	public void foo() {
 		int x= 0;
-		int y= 0;
-
 		extracted(x);		
 	}
 

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/locals_out/A_test518.java

@@ -2,8 +2,6 @@
 
 public class A_test518 {
 	public void foo() {
-		int i;
-
 		extracted();
 	}
 

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/validSelection_in/A_testIssue1357_1.java

@@ -0,0 +1,21 @@
+package validSelection_in;
+
+public class A_testIssue1357_1 {
+
+    public synchronized int calculate() {
+        int result;
+        /*]*/switch (value) {
+        case 1:
+            result = value * 2;
+            break;
+        case 2:
+            result = value * 3;
+            break;
+        default:
+            result = value * 4;
+            break;
+        }
+        return result;/*[*/
+    }
+
+}

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/validSelection_in/A_testIssue1357_2.java

@@ -0,0 +1,21 @@
+package validSelection_in;
+
+public class A_testIssue1357_2 {
+
+    public synchronized int calculate() {
+        int result;
+        /*]*/switch (value) {
+        case 1:
+            result = value * 2;
+            break;
+        case 2:
+            result = value * 3;
+            break;
+        default:
+            result = value * 4;
+            break;
+        }/*[*/
+        return result;
+    }
+
+}

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/validSelection_out/A_testIssue1357_1.java

@@ -0,0 +1,25 @@
+package validSelection_out;
+
+public class A_testIssue1357_1 {
+
+    public synchronized int calculate() {
+        return extracted();/*[*/
+    }
+
+	protected int extracted() {
+		int result;
+		switch (value) {
+        case 1:
+            result = value * 2;
+            break;
+        case 2:
+            result = value * 3;
+            break;
+        default:
+            result = value * 4;
+            break;
+        }
+        return result;
+	}
+
+}

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/validSelection_out/A_testIssue1357_2.java

@@ -0,0 +1,27 @@
+package validSelection_out;
+
+public class A_testIssue1357_2 {
+
+    public synchronized int calculate() {
+        int result;
+        /*]*/result = extracted();/*[*/
+        return result;
+    }
+
+	protected int extracted() {
+		int result;
+		switch (value) {
+        case 1:
+            result = value * 2;
+            break;
+        case 2:
+            result = value * 3;
+            break;
+        default:
+            result = value * 4;
+            break;
+        }
+		return result;
+	}
+
+}

org.eclipse.jdt.ui.tests.refactoring/resources/ExtractMethodWorkSpace/ExtractMethodTests/wiki_out/A_test2001.java

@@ -5,7 +5,6 @@ public class A_test2001 {
 	int field= 0;
 
 	void fun() {
-		int i;
 		extracted();
 	}
 

org.eclipse.jdt.ui.tests.refactoring/test cases/org/eclipse/jdt/ui/tests/refactoring/ExtractMethodTests.java

@@ -2700,4 +2700,14 @@ public void testIssue1356_1() throws Exception {
 	public void testIssue1356_2() throws Exception {
 		invalidSelectionTest();
 	}
+
+	@Test
+	public void testIssue1357_1() throws Exception {
+		validSelectionTestChecked();
+	}
+
+	@Test
+	public void testIssue1357_2() throws Exception {
+		validSelectionTestChecked();
+	}
 }