Update MustBeClosed to handle IO decorators.

Tested:
    TAP for global presubmit queue
    []
PiperOrigin-RevId: 673522715

core/src/main/java/com/google/errorprone/bugpatterns/AbstractMustBeClosedChecker.java

@@ -16,6 +16,7 @@
 
 package com.google.errorprone.bugpatterns;
 
+import static com.google.errorprone.bugpatterns.CloseableDecoratorTypes.CLOSEABLE_DECORATOR_TYPES;
 import static com.google.errorprone.fixes.SuggestedFixes.prettyType;
 import static com.google.errorprone.fixes.SuggestedFixes.qualifyType;
 import static com.google.errorprone.matchers.Description.NO_MATCH;
@@ -62,6 +63,7 @@
 import com.sun.source.util.TreePath;
 import com.sun.source.util.TreeScanner;
 import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.Symbol.MethodSymbol;
 import com.sun.tools.javac.code.Symbol.VarSymbol;
 import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.util.Position;
@@ -299,6 +301,17 @@ && isSameType(type.getReturnType(), streamType, state)) {
             }
           }
           break;
+        case NEW_CLASS:
+          NewClassTree newClassTree = (NewClassTree) path.getLeaf();
+          if (isClosingDecorator(newClassTree, prev.getLeaf(), state)) {
+            if (HAS_MUST_BE_CLOSED_ANNOTATION.matches(newClassTree, state)) {
+              // if the decorator is also annotated then it would already be enforced
+              return Optional.empty();
+            }
+            // otherwise, enforce that the decorator must be closed
+            continue OUTER;
+          }
+          break;
         case VARIABLE:
           Symbol sym = getSymbol(path.getLeaf());
           if (sym instanceof VarSymbol) {
@@ -520,4 +533,29 @@ private static Optional<Change> wrapTryFinallyAroundVariableScope(
         .closeBraceAfter(enclosingBlock)
         .wrapped();
   }
+
+  /**
+   * Returns true if {@code decorator} is the instantiation of an {@link AutoCloseable} decorator
+   * type that decorates the given {@code resource} and always closes the decorated {@code resource}
+   * when closed.
+   */
+  private static boolean isClosingDecorator(
+      NewClassTree decorator, Tree resource, VisitorState state) {
+    if (decorator.getArguments().isEmpty() || !decorator.getArguments().get(0).equals(resource)) {
+      // we assume the decorated resource is always the first argument to the decorator constructor
+      return false;
+    }
+    MethodSymbol constructor = getSymbol(decorator);
+    if (!constructor.getThrownTypes().isEmpty()) {
+      // resource would not be closed if the decorator constructor throws
+      return false;
+    }
+    Type resourceType = constructor.params().get(0).type;
+    Type decoratorType = constructor.owner.type;
+    return CLOSEABLE_DECORATOR_TYPES.keySet().stream()
+        .filter(key -> isSameType(resourceType, state.getTypeFromString(key), state))
+        .limit(1)
+        .flatMap(key -> CLOSEABLE_DECORATOR_TYPES.get(key).stream())
+        .anyMatch(value -> isSubtype(decoratorType, state.getTypeFromString(value), state));
+  }
 }

core/src/main/java/com/google/errorprone/bugpatterns/CloseableDecoratorTypes.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2024 The Error Prone Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.errorprone.bugpatterns;
+
+import com.google.common.collect.ImmutableSetMultimap;
+import java.io.FilterInputStream;
+import java.io.FilterOutputStream;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Reader;
+import java.io.Writer;
+
+/**
+ * Common {@link AutoCloseable} decorator types that wrap around {@link AutoCloseable} resources,
+ * which are always closed when the enclosing decorators are closed.
+ *
+ * <p>Each value in the map is the common supertype of some {@link AutoCloseable} decorator types,
+ * with the key being the common {@link AutoCloseable} type that they decorate. The decorated type
+ * is always assumed to be the first argument to the constructor of the decorator type.
+ */
+public final class CloseableDecoratorTypes {
+  public static final ImmutableSetMultimap<String, String> CLOSEABLE_DECORATOR_TYPES =
+      ImmutableSetMultimap.<String, String>builder()
+          .putAll(
+              InputStream.class.getName(),
+              FilterInputStream.class.getName(), // e.g., BufferedInputStream
+              InputStreamReader.class.getName())
+          .putAll(
+              OutputStream.class.getName(),
+              FilterOutputStream.class.getName(), // e.g., BufferedOutputStream
+              OutputStreamWriter.class.getName())
+          .put(Reader.class.getName(), Reader.class.getName()) // e.g., BufferedReader
+          .put(Writer.class.getName(), Writer.class.getName()) // e.g., BufferedWriter
+          .build();
+
+  private CloseableDecoratorTypes() {}
+}