Java: Fixed removing unused variable occurrences from 'for' loop's update and init clauses (IDEA-180217)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/quickfix/RemoveUnusedVariableUtil.java

@@ -59,6 +59,12 @@ public class RemoveUnusedVariableUtil {
       elementToReplace = element.getParent();
       expressionToReplaceWith =
       factory.createStatementFromText((expression == null ? "" : expression.getText()) + ";", null);
+      if (isForLoopUpdate(elementToReplace)) {
+        PsiElement lastChild = expressionToReplaceWith.getLastChild();
+        if (PsiUtil.isJavaToken(lastChild, JavaTokenType.SEMICOLON)) {
+          lastChild.delete();
+        }
+      }
     }
     else if (element.getParent() instanceof PsiDeclarationStatement) {
       expressionToReplaceWith =
@@ -83,7 +89,7 @@ public class RemoveUnusedVariableUtil {
     // just delete it altogether
     if (element.getParent() instanceof PsiExpressionStatement) {
       PsiExpressionStatement parent = (PsiExpressionStatement)element.getParent();
-      if (parent.getParent() instanceof PsiCodeBlock) {
+      if (parent.getParent() instanceof PsiCodeBlock || isForLoopUpdate(parent)) {
         parent.delete();
       }
       else {
@@ -134,7 +140,7 @@ public class RemoveUnusedVariableUtil {
         if (rExpression == null) return true;
         // replace assignment with expression and resimplify
         boolean sideEffectFound = checkSideEffects(rExpression, variable, sideEffects);
-        if (!(element.getParent() instanceof PsiExpressionStatement) || PsiUtil.isStatement(rExpression)) {
+        if (!isStatementExpression(expression) || PsiUtil.isStatement(rExpression)) {
           if (deleteMode == RemoveMode.MAKE_STATEMENT ||
               deleteMode == RemoveMode.DELETE_ALL && !(element.getParent() instanceof PsiExpressionStatement)) {
             element = replaceElementWithExpression(rExpression, factory, element);
@@ -201,4 +207,16 @@ public class RemoveUnusedVariableUtil {
     }
     return true;
   }
+
+  private static boolean isForLoopUpdate(PsiElement element) {
+    PsiElement parent = element.getParent();
+    return parent instanceof PsiForStatement &&
+           ((PsiForStatement)parent).getUpdate() == element;
+  }
+
+  private static boolean isStatementExpression(PsiExpression expression) {
+    PsiElement parent = expression.getParent();
+    return parent instanceof PsiExpressionStatement ||
+           parent instanceof PsiExpressionList && parent.getParent() instanceof PsiExpressionListStatement;
+  }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForInit1.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        int i = 10;
+        for(; (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForInit2.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        int i;
+        for(i = 10; (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForInit3.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        int i = 10;
+        for(foo(); (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForInit4.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        int i;
+        for(i = 10, foo(); (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForUpdate1.java

@@ -0,0 +1,10 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        for(int i = 10; (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForUpdate2.java

@@ -0,0 +1,10 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case02() {
+        for(int i = 10; i > 0; i--) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForUpdate3.java

@@ -0,0 +1,10 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        for(int i = 10; (--i) > 0; foo()) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/afterForUpdate4.java

@@ -0,0 +1,10 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        for(int i = 10; i > 0; --i, foo()) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForInit1.java

@@ -0,0 +1,12 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        Object <caret>problematic;
+        int i = 10;
+        for(problematic = foo; (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForInit2.java

@@ -0,0 +1,12 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        Object <caret>problematic;
+        int i;
+        for(i = 10, problematic = foo; (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForInit3.java

@@ -0,0 +1,12 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        Object <caret>problematic;
+        int i = 10;
+        for(problematic = foo(); (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForInit4.java

@@ -0,0 +1,12 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        Object <caret>problematic;
+        int i;
+        for(i = 10, problematic = foo(); (--i) > 0; ) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForUpdate1.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case01() {
+        Object <caret>problematic;
+        for(int i = 10; (--i) > 0; problematic = foo) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForUpdate2.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo = null;
+
+    void case02() {
+        Object <caret>problematic;
+        for(int i = 10; i > 0; i--, problematic = foo) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForUpdate3.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        Object <caret>problematic;
+        for(int i = 10; (--i) > 0; problematic = foo()) {
+            System.out.println("index = " + i);
+        }
+    }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/removeUnusedVariable/beforeForUpdate4.java

@@ -0,0 +1,11 @@
+// "Remove variable 'problematic'" "true"
+class C {
+    Object foo() {return null;}
+
+    void case01() {
+        Object <caret>problematic;
+        for(int i = 10; i > 0; --i, problematic = foo()) {
+            System.out.println("index = " + i);
+        }
+    }
+}