From 0fe0c296c4ba5009319a0c0f0d34fc4839aeb5a8 Mon Sep 17 00:00:00 2001
From: Pavel Dolgov <pavel.dolgov@jetbrains.com>
Date: Thu, 12 Oct 2017 16:01:39 +0300
Subject: [PATCH] Java: Extract method from similar expressions by introducing
 a parameter (IDEA-179924, IDEA-180107)

---
 .../util/duplicates/DuplicatesFinder.java            |  3 +++
 .../extractMethod/ExtractMethodProcessor.java        |  4 +++-
 .../SuggestChangeSignatureTwoFieldInitializers.java  |  4 ++++
 ...estChangeSignatureTwoFieldInitializers_after.java | 12 ++++++++++++
 .../intellij/java/refactoring/ExtractMethodTest.java |  4 ++++
 5 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers.java
 create mode 100644 java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers_after.java

diff --git a/java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesFinder.java b/java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesFinder.java
index 449e1f4e754c..203f1d21efc1 100644
--- a/java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesFinder.java
+++ b/java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesFinder.java
@@ -573,6 +573,9 @@ public class DuplicatesFinder {
     if (!(pattern instanceof PsiExpression) || !(candidate instanceof PsiExpression) || withFolding && !myWithExtractedParameters) {
       return null;
     }
+    if (myPattern.length == 1 && myPattern[0] == pattern || candidates.size() == 1 && candidates.get(0) == candidate) {
+      return null;
+    }
 
     ComplexityHolder patternComplexity = null;
     if (withFolding) {
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 0ff5fba96ba8..a827c63aa40d 100644
--- a/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java
+++ b/java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java
@@ -231,7 +231,9 @@ public class ExtractMethodProcessor implements MatchProvider {
       myCodeFragmentMember = codeFragment.getParent();
     }
     if (myCodeFragmentMember == null) {
-      myCodeFragmentMember = ControlFlowUtil.findCodeFragment(codeFragment.getContext()).getParent();
+      PsiElement context = codeFragment.getContext();
+      LOG.assertTrue(context != null, "code fragment context is null");
+      myCodeFragmentMember = ControlFlowUtil.findCodeFragment(context).getParent();
     }
 
     myControlFlowWrapper = new ControlFlowWrapper(myProject, codeFragment, myElements);
diff --git a/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers.java b/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers.java
new file mode 100644
index 000000000000..16ac33bb4d3a
--- /dev/null
+++ b/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers.java
@@ -0,0 +1,4 @@
+public class C {
+    String f1 = <selection>"a" + "b"</selection>;
+    String f2 = "c" + "b";
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers_after.java b/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers_after.java
new file mode 100644
index 000000000000..4e8099d93c1e
--- /dev/null
+++ b/java/java-tests/testData/refactoring/extractMethod/SuggestChangeSignatureTwoFieldInitializers_after.java
@@ -0,0 +1,12 @@
+import org.jetbrains.annotations.NotNull;
+
+public class C {
+    String f1 = newMethod("a");
+
+    @NotNull
+    private String newMethod(String a) {
+        return a + "b";
+    }
+
+    String f2 = newMethod("c");
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java b/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java
index fd2fc12f4c8b..3974c94802b4 100644
--- a/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java
@@ -839,6 +839,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doDuplicatesTest();
   }
 
+  public void testSuggestChangeSignatureTwoFieldInitializers() throws Exception {
+    doDuplicatesTest();
+  }
+
   public void testSuggestChangeSignatureWithChangedParameterName() throws Exception {
     configureByFile(BASE_PATH + getTestName(false) + ".java");
     boolean success = performExtractMethod(true, true, getEditor(), getFile(), getProject(), false, null, false, "p");