From 8a71cfc4049d35b016697c43bd9c414992477c31 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 15 Sep 2014 14:40:47 +0200
Subject: [PATCH] don't blink with pure contract on gutter when starting to
 write a method

---
 .../codeInspection/dataFlow/PurityInference.java      | 11 ++++++++++-
 .../PurityInferenceFromSourceTest.groovy              |  9 +++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/PurityInference.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/PurityInference.java
index 2e6d3dac06ba..29f530aba0f6 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/PurityInference.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/PurityInference.java
@@ -58,6 +58,7 @@ public class PurityInference {
     if (body == null) return false;
 
     final Ref<Boolean> impureFound = Ref.create(false);
+    final Ref<Boolean> hasReturns = Ref.create(false);
     final List<PsiMethodCallExpression> calls = ContainerUtil.newArrayList();
     body.accept(new JavaRecursiveElementWalkingVisitor() {
       @Override
@@ -68,6 +69,14 @@ public class PurityInference {
         super.visitAssignmentExpression(expression);
       }
 
+      @Override
+      public void visitReturnStatement(PsiReturnStatement statement) {
+        if (statement.getReturnValue() != null) {
+          hasReturns.set(true);
+        }
+        super.visitReturnStatement(statement);
+      }
+
       @Override
       public void visitPrefixExpression(PsiPrefixExpression expression) {
         if (isMutatingOperation(expression.getOperationTokenType()) && !isLocalVarReference(expression.getOperand())) {
@@ -95,7 +104,7 @@ public class PurityInference {
       }
     });
 
-    if (impureFound.get() || calls.size() > 1) return false;
+    if (impureFound.get() || calls.size() > 1 || !hasReturns.get()) return false;
     if (calls.isEmpty()) return true;
 
     final PsiMethod called = calls.get(0).resolveMethod();
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/PurityInferenceFromSourceTest.groovy b/java/java-tests/testSrc/com/intellij/codeInspection/PurityInferenceFromSourceTest.groovy
index 815155e61fd2..c21e09c00a11 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/PurityInferenceFromSourceTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/codeInspection/PurityInferenceFromSourceTest.groovy
@@ -120,6 +120,15 @@ int smthPure() { return 3; }
 """
   }
 
+  public void "test don't analyze methods without returns"() {
+    assertPure false, """
+Object method() {
+    smthPure();
+}
+int smthPure() { return 3; }
+"""
+  }
+
   private void assertPure(boolean expected, String classBody) {
     def clazz = myFixture.addClass("final class Foo { $classBody }")
     assert expected == PurityInference.inferPurity(clazz.methods[0])