StreamApiMigrationInspection: correctly handle anonymous classes/lambdas (IDEA-CR-14138)

java/java-analysis-impl/src/com/intellij/codeInspection/streamMigration/StreamApiMigrationInspection.java

@@ -409,12 +409,15 @@ public class StreamApiMigrationInspection extends BaseJavaBatchLocalInspectionTo
   }
 
   static InitializerUsageStatus getInitializerUsageStatus(PsiVariable var, PsiStatement nextStatement) {
-    if(var.getInitializer() == null) return UNKNOWN;
+    if(!(var instanceof PsiLocalVariable) || var.getInitializer() == null) return UNKNOWN;
     if(isDeclarationJustBefore(var, nextStatement)) return DECLARED_JUST_BEFORE;
     PsiElement declaration = var.getParent();
     // Check if variable is not referenced in the same declaration like "int a = 0, b = a;"
     if(!PsiTreeUtil.processElements(declaration, e -> !(e instanceof PsiReferenceExpression) ||
                                                   ((PsiReferenceExpression)e).resolve() != var)) return UNKNOWN;
+    // Check that variable is declared in the same method or the same lambda expression
+    if(PsiTreeUtil.getParentOfType(var, PsiLambdaExpression.class, PsiMethod.class) !=
+       PsiTreeUtil.getParentOfType(nextStatement, PsiLambdaExpression.class, PsiMethod.class)) return UNKNOWN;
     PsiElement block = PsiUtil.getVariableCodeBlock(var, null);
     if(block == null) return UNKNOWN;
     final ControlFlow controlFlow;

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/afterCollectWithSameLambda.java

@@ -0,0 +1,15 @@
+// "Replace with collect" "true"
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class Collect {
+  public static void collectWithLambda(List<String> test) {
+    Runnable r = () -> {
+      List<String> result;
+      System.out.println("We're inside the lambda");
+        result = test.stream().map(String::trim).collect(Collectors.toList());
+      System.out.println(result);
+    };
+    r.run();
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeCollectWithAnonymous.java

@@ -0,0 +1,18 @@
+// "Replace with collect" "false"
+import java.util.*;
+
+public class Collect {
+  public static void collectWithAnonymous(List<String> test) {
+    List<String> result = new ArrayList<>();
+    Runnable r = new Runnable() {
+      @Override
+      public void run() {
+        for (String str : te<caret>st) {
+          result.add(str.trim());
+        }
+      }
+    };
+    r.run();
+    System.out.println(result);
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeCollectWithLambda.java

@@ -0,0 +1,15 @@
+// "Replace with collect" "false"
+import java.util.*;
+
+public class Collect {
+  public static void collectWithLambda(List<String> test) {
+    List<String> result = new ArrayList<>();
+    Runnable r = () -> {
+      for(String str : te<caret>st) {
+        result.add(str.trim());
+      }
+    };
+    r.run();
+    System.out.println(result);
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeCollectWithSameLambda.java

@@ -0,0 +1,16 @@
+// "Replace with collect" "true"
+import java.util.*;
+
+public class Collect {
+  public static void collectWithLambda(List<String> test) {
+    Runnable r = () -> {
+      List<String> result = new ArrayList<>();
+      System.out.println("We're inside the lambda");
+      for(String str : te<caret>st) {
+        result.add(str.trim());
+      }
+      System.out.println(result);
+    };
+    r.run();
+  }
+}