IG: handle fluent api method chains (IDEA-157151)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/resources/ResourceInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2015 Bas Leijdekkers
+ * Copyright 2008-2016 Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -112,7 +112,7 @@ public abstract class ResourceInspection extends BaseInspection {
 
   @Nullable
   public static PsiVariable getVariable(@NotNull PsiExpression expression) {
-    final PsiElement parent = ParenthesesUtils.getParentSkipParentheses(expression);
+    final PsiElement parent = getParent(expression);
     if (parent instanceof PsiAssignmentExpression) {
       final PsiAssignmentExpression assignment = (PsiAssignmentExpression)parent;
       final PsiExpression lhs = assignment.getLExpression();
@@ -134,6 +134,30 @@ public abstract class ResourceInspection extends BaseInspection {
     }
   }
 
+  private static PsiElement getParent(PsiExpression expression) {
+    PsiElement parent = ParenthesesUtils.getParentSkipParentheses(expression);
+    if (parent == null) {
+      return null;
+    }
+    PsiElement grandParent = parent.getParent();
+    final PsiType type = expression.getType();
+    if (type == null) {
+      return null;
+    }
+    while (parent instanceof PsiReferenceExpression && grandParent instanceof PsiMethodCallExpression) {
+      final PsiMethodCallExpression methodCallExpression = (PsiMethodCallExpression)grandParent;
+      if (!type.equals(methodCallExpression.getType())) {
+        return null;
+      }
+      parent = ParenthesesUtils.getParentSkipParentheses(grandParent);
+      if (parent == null) {
+        return null;
+      }
+      grandParent = parent.getParent();
+    }
+    return parent;
+  }
+
   private boolean isSafelyClosed(@Nullable PsiVariable variable, PsiElement context) {
     if (variable == null) {
       return false;

plugins/InspectionGadgets/testsrc/com/siyeh/ig/resources/AutoCloseableResourceInspectionTest.java

@@ -138,6 +138,19 @@ public class AutoCloseableResourceInspectionTest extends LightInspectionTestCase
            "}");
   }
 
+  public void testScanner() {
+    doTest("import java.util.Scanner;" +
+           "class A {" +
+           "    void a() throws java.io.IOException {" +
+           "        try (Scanner scanner = new Scanner(\"\").useDelimiter(\"\\\\A\")) {" +
+           "            String sconf = scanner.next();" +
+           "            System.out.println(sconf);" +
+           "        }" +
+           "    }" +
+           "}" +
+           "");
+  }
+
   @Override
   protected LocalInspectionTool getInspection() {
     return new AutoCloseableResourceInspection();
@@ -147,10 +160,20 @@ public class AutoCloseableResourceInspectionTest extends LightInspectionTestCase
   protected String[] getEnvironmentClasses() {
     return new String[] {
       "package java.util;" +
-      "public final class Formatter implements Closeable {" +
+      "public final class Formatter implements java.io.Closeable {" +
       "    public Formatter format(String format, Object ... args) {" +
       "      return this;" +
       "    }" +
+      "}",
+      "package java.util;" +
+      "public final class Scanner implements java.io.Closeable {" +
+      "    public Scanner(String source) {}" +
+      "    public Scanner useDelimiter(String pattern) {" +
+      "         return this;" +
+      "    }" +
+      "    public String next() {" +
+      "        return this;" +
+      "    }" +
       "}"
     };
   }