From f3d22142cd710d805850eb3ac6504fd961bac025 Mon Sep 17 00:00:00 2001
From: Pavel Dolgov <pavel.dolgov@jetbrains.com>
Date: Wed, 7 Sep 2016 18:48:46 +0300
Subject: [PATCH] Java inspection: Don't look for assignment chains in 'switch'
 and loop statements in "Move return to computation" inspection (IDEA-121153)

---
 ...urnSeparatedFromComputationInspection.java |  8 +++++-
 .../afterSwitchThrow.java                     | 23 ++++++++++++++++
 .../beforeSwitchThrow.java                    | 27 +++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/afterSwitchThrow.java
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/beforeSwitchThrow.java

diff --git a/java/java-impl/src/com/intellij/codeInspection/intermediaryVariable/ReturnSeparatedFromComputationInspection.java b/java/java-impl/src/com/intellij/codeInspection/intermediaryVariable/ReturnSeparatedFromComputationInspection.java
index d17fe690b12f..af3d772815e4 100644
--- a/java/java-impl/src/com/intellij/codeInspection/intermediaryVariable/ReturnSeparatedFromComputationInspection.java
+++ b/java/java-impl/src/com/intellij/codeInspection/intermediaryVariable/ReturnSeparatedFromComputationInspection.java
@@ -383,7 +383,8 @@ public class ReturnSeparatedFromComputationInspection extends BaseJavaBatchLocal
       PsiJavaToken rBrace = codeBlock.getRBrace();
       if (rBrace != null) {
         PsiStatement lastNonEmptyStatement = getPrevNonEmptyStatement(rBrace, removeCompletely);
-        if (lastNonEmptyStatement == null || hasChainedAssignmentsInScope(flow, resultVariable, lastNonEmptyStatement)) {
+        if (lastNonEmptyStatement == null ||
+            isIfBranch(codeBlock) && hasChainedAssignmentsInScope(flow, resultVariable, lastNonEmptyStatement)) {
           return false;
         }
         if (moveTo(lastNonEmptyStatement, returnAtTheEnd)) {
@@ -507,6 +508,11 @@ public class ReturnSeparatedFromComputationInspection extends BaseJavaBatchLocal
       return ExpressionUtils.computeConstantExpression(condition) == Boolean.TRUE;
     }
 
+    private static boolean isIfBranch(@NotNull PsiCodeBlock codeBlock) {
+      final PsiElement parent = codeBlock.getParent();
+      return parent instanceof PsiBlockStatement && parent.getParent() instanceof PsiIfStatement;
+    }
+
     private Set<PsiBreakStatement> getBreaks(@NotNull PsiStatement targetStatement) {
       if (breakStatements == null) {
         breakStatements = new THashMap<>();
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/afterSwitchThrow.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/afterSwitchThrow.java
new file mode 100644
index 000000000000..52bda5b86ee7
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/afterSwitchThrow.java
@@ -0,0 +1,23 @@
+// "Move 'return' closer to computation of the value of 'n'" "true"
+class T {
+    int f(int a) {
+        int n = -1;
+        switch (a) {
+            case 0:
+            case 1:
+            case 2:
+                return n;
+            case 10:
+            case 20:
+                return n + 1;
+            case 30:
+            case 40:
+            case 50:
+                return 2;
+            case 90:
+                return 3;
+            default:
+                throw new IllegalArgumentException();
+        }
+    }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/beforeSwitchThrow.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/beforeSwitchThrow.java
new file mode 100644
index 000000000000..5fd61be245f7
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/returnSeparatedFromComputation/beforeSwitchThrow.java
@@ -0,0 +1,27 @@
+// "Move 'return' closer to computation of the value of 'n'" "true"
+class T {
+    int f(int a) {
+        int n = -1;
+        switch (a) {
+            case 0:
+            case 1:
+            case 2:
+                break;
+            case 10:
+            case 20:
+                n = n + 1;
+                break;
+            case 30:
+            case 40:
+            case 50:
+                n = 2;
+                break;
+            case 90:
+                n = 3;
+                break;
+            default:
+                throw new IllegalArgumentException();
+        }
+        r<caret>eturn n;
+    }
+}
\ No newline at end of file