Add a strict mode of sorts to InMemoryFileSystem to detect handle leaks.

okhttp-testing-support/src/main/java/com/squareup/okhttp/internal/io/InMemoryFileSystem.java

@@ -18,32 +18,95 @@ package com.squareup.okhttp.internal.io;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.IdentityHashMap;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import okio.Buffer;
+import okio.ForwardingSink;
+import okio.ForwardingSource;
 import okio.Sink;
 import okio.Source;
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
 
 /** A simple file system where all files are held in memory. Not safe for concurrent use. */
-public final class InMemoryFileSystem implements FileSystem {
+public final class InMemoryFileSystem implements FileSystem, TestRule {
   private final Map<File, Buffer> files = new LinkedHashMap<>();
+  private final Map<Source, File> openSources = new IdentityHashMap<>();
+  private final Map<Sink, File> openSinks = new IdentityHashMap<>();
+
+  @Override public Statement apply(final Statement base, Description description) {
+    return new Statement() {
+      @Override public void evaluate() throws Throwable {
+        base.evaluate();
+        ensureResourcesClosed();
+      }
+    };
+  }
+
+  public void ensureResourcesClosed() {
+    List<String> openResources = new ArrayList<>();
+    for (File file : openSources.values()) {
+      openResources.add("Source for " + file);
+    }
+    for (File file : openSinks.values()) {
+      openResources.add("Sink for " + file);
+    }
+    if (!openResources.isEmpty()) {
+      StringBuilder builder = new StringBuilder("Resources acquired but not closed:");
+      for (String resource : openResources) {
+        builder.append("\n * ").append(resource);
+      }
+      throw new IllegalStateException(builder.toString());
+    }
+  }
 
   @Override public Source source(File file) throws FileNotFoundException {
     Buffer result = files.get(file);
     if (result == null) throw new FileNotFoundException();
-    return result.clone();
+
+    final Source source = result.clone();
+    openSources.put(source, file);
+
+    return new ForwardingSource(source) {
+      @Override public void close() throws IOException {
+        openSources.remove(source);
+        super.close();
+      }
+    };
   }
 
   @Override public Sink sink(File file) throws FileNotFoundException {
-    Buffer result = new Buffer();
+    return sink(file, false);
-    files.put(file, result);
-    return result;
   }
 
   @Override public Sink appendingSink(File file) throws FileNotFoundException {
-    Buffer result = files.get(file);
+    return sink(file, true);
-    return result != null ? result : sink(file);
+  }
+
+  private Sink sink(File file, boolean appending) {
+    Buffer result = null;
+    if (appending) {
+      result = files.get(file);
+    }
+    if (result == null) {
+      result = new Buffer();
+    }
+    files.put(file, result);
+
+    final Sink sink = result;
+    openSinks.put(sink, file);
+
+    return new ForwardingSink(sink) {
+      @Override public void close() throws IOException {
+        openSinks.remove(sink);
+        super.close();
+      }
+    };
   }
 
   @Override public void delete(File file) throws IOException {

okhttp-tests/src/test/java/com/squareup/okhttp/CacheTest.java

@@ -19,7 +19,6 @@ package com.squareup.okhttp;
 import com.squareup.okhttp.internal.Internal;
 import com.squareup.okhttp.internal.SslContextBuilder;
 import com.squareup.okhttp.internal.Util;
-import com.squareup.okhttp.internal.io.FileSystem;
 import com.squareup.okhttp.internal.io.InMemoryFileSystem;
 import com.squareup.okhttp.mockwebserver.MockResponse;
 import com.squareup.okhttp.mockwebserver.MockWebServer;
@@ -76,9 +75,9 @@ public final class CacheTest {
 
   @Rule public MockWebServer server = new MockWebServer();
   @Rule public MockWebServer server2 = new MockWebServer();
+  @Rule public InMemoryFileSystem fileSystem = new InMemoryFileSystem();
 
   private final SSLContext sslContext = SslContextBuilder.localhost();
-  private final FileSystem fileSystem = new InMemoryFileSystem();
   private final OkHttpClient client = new OkHttpClient();
   private Cache cache;
   private final CookieManager cookieManager = new CookieManager();
@@ -93,6 +92,7 @@ public final class CacheTest {
   @After public void tearDown() throws Exception {
     ResponseCache.setDefault(null);
     CookieHandler.setDefault(null);
+    cache.delete();
   }
 
   /**
@@ -266,7 +266,7 @@ public final class CacheTest {
     Principal localPrincipal = response1.handshake().localPrincipal();
 
     Response response2 = client.newCall(request).execute(); // Cached!
-    assertEquals("ABC", response2.body().source().readUtf8());
+    assertEquals("ABC", response2.body().string());
 
     assertEquals(2, cache.getRequestCount());
     assertEquals(1, cache.getNetworkCount());
@@ -1873,6 +1873,7 @@ public final class CacheTest {
 
     Response response = get(server.url("/"));
     assertEquals("A", response.header(""));
+    assertEquals("body", response.body().string());
   }
 
   /**

okhttp-tests/src/test/java/com/squareup/okhttp/CallTest.java

@@ -22,7 +22,6 @@ import com.squareup.okhttp.internal.SingleInetAddressNetwork;
 import com.squareup.okhttp.internal.SslContextBuilder;
 import com.squareup.okhttp.internal.Util;
 import com.squareup.okhttp.internal.Version;
-import com.squareup.okhttp.internal.io.FileSystem;
 import com.squareup.okhttp.internal.io.InMemoryFileSystem;
 import com.squareup.okhttp.mockwebserver.Dispatcher;
 import com.squareup.okhttp.mockwebserver.MockResponse;
@@ -88,9 +87,9 @@ public final class CallTest {
   @Rule public final TestRule timeout = new Timeout(30_000);
   @Rule public final MockWebServer server = new MockWebServer();
   @Rule public final MockWebServer server2 = new MockWebServer();
+  @Rule public final InMemoryFileSystem fileSystem = new InMemoryFileSystem();
 
   private SSLContext sslContext = SslContextBuilder.localhost();
-  private FileSystem fileSystem = new InMemoryFileSystem();
   private OkHttpClient client = new OkHttpClient();
   private RecordingCallback callback = new RecordingCallback();
   private TestLogHandler logHandler = new TestLogHandler();

okhttp-tests/src/test/java/com/squareup/okhttp/RecordingCallback.java

@@ -20,7 +20,6 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
-import okio.Buffer;
 
 /**
  * Records received HTTP responses so they can be later retrieved by tests.
@@ -36,11 +35,8 @@ public class RecordingCallback implements Callback {
   }
 
   @Override public synchronized void onResponse(Response response) throws IOException {
-    Buffer buffer = new Buffer();
+    String body = response.body().string();
-    ResponseBody body = response.body();
+    responses.add(new RecordedResponse(response.request(), response, null, body, null));
-    body.source().readAll(buffer);
-
-    responses.add(new RecordedResponse(response.request(), response, null, buffer.readUtf8(), null));
     notifyAll();
   }
 

okhttp-urlconnection/src/test/java/com/squareup/okhttp/OkUrlFactoryTest.java

@@ -1,7 +1,6 @@
 package com.squareup.okhttp;
 
 import com.squareup.okhttp.internal.Platform;
-import com.squareup.okhttp.internal.io.FileSystem;
 import com.squareup.okhttp.internal.io.InMemoryFileSystem;
 import com.squareup.okhttp.mockwebserver.MockResponse;
 import com.squareup.okhttp.mockwebserver.MockWebServer;
@@ -14,6 +13,8 @@ import java.util.Date;
 import java.util.Locale;
 import java.util.TimeZone;
 import java.util.concurrent.TimeUnit;
+import okio.BufferedSource;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -26,16 +27,22 @@ import static org.junit.Assert.fail;
 
 public class OkUrlFactoryTest {
   @Rule public MockWebServer server = new MockWebServer();
+  @Rule public InMemoryFileSystem fileSystem = new InMemoryFileSystem();
 
-  private FileSystem fileSystem = new InMemoryFileSystem();
   private OkUrlFactory factory;
+  private Cache cache;
 
   @Before public void setUp() throws IOException {
     OkHttpClient client = new OkHttpClient();
-    client.setCache(new Cache(new File("/cache/"), 10 * 1024 * 1024, fileSystem));
+    cache = new Cache(new File("/cache/"), 10 * 1024 * 1024, fileSystem);
+    client.setCache(cache);
     factory = new OkUrlFactory(client);
   }
 
+  @After public void tearDown() throws IOException {
+    cache.delete();
+  }
+
   /**
    * Response code 407 should only come from proxy servers. Android's client
    * throws if it is sent by an origin server.
@@ -64,6 +71,7 @@ public class OkUrlFactoryTest {
 
     HttpURLConnection connection = factory.open(server.getUrl("/"));
     assertResponseHeader(connection, "NETWORK 404");
+    connection.getErrorStream().close();
   }
 
   @Test public void conditionalCacheHitResponseSourceHeaders() throws Exception {
@@ -140,7 +148,9 @@ public class OkUrlFactoryTest {
   }
 
   private void assertResponseBody(HttpURLConnection connection, String expected) throws Exception {
-    String actual = buffer(source(connection.getInputStream())).readString(US_ASCII);
+    BufferedSource source = buffer(source(connection.getInputStream()));
+    String actual = source.readString(US_ASCII);
+    source.close();
     assertEquals(expected, actual);
   }
 

okhttp-urlconnection/src/test/java/com/squareup/okhttp/UrlConnectionCacheTest.java

@@ -19,7 +19,6 @@ package com.squareup.okhttp;
 import com.squareup.okhttp.internal.Internal;
 import com.squareup.okhttp.internal.SslContextBuilder;
 import com.squareup.okhttp.internal.Util;
-import com.squareup.okhttp.internal.io.FileSystem;
 import com.squareup.okhttp.internal.io.InMemoryFileSystem;
 import com.squareup.okhttp.mockwebserver.MockResponse;
 import com.squareup.okhttp.mockwebserver.MockWebServer;
@@ -81,9 +80,9 @@ public final class UrlConnectionCacheTest {
 
   @Rule public MockWebServer server = new MockWebServer();
   @Rule public MockWebServer server2 = new MockWebServer();
+  @Rule public InMemoryFileSystem fileSystem = new InMemoryFileSystem();
 
   private final SSLContext sslContext = SslContextBuilder.localhost();
-  private final FileSystem fileSystem = new InMemoryFileSystem();
   private final OkUrlFactory client = new OkUrlFactory(new OkHttpClient());
   private Cache cache;
   private final CookieManager cookieManager = new CookieManager();
@@ -98,6 +97,7 @@ public final class UrlConnectionCacheTest {
   @After public void tearDown() throws Exception {
     ResponseCache.setDefault(null);
     CookieHandler.setDefault(null);
+    cache.delete();
   }
 
   @Test public void responseCacheAccessWithOkHttpMember() throws IOException {
@@ -1586,6 +1586,7 @@ public final class UrlConnectionCacheTest {
 
     HttpURLConnection connection = client.open(server.getUrl("/"));
     assertEquals("A", connection.getHeaderField(""));
+    assertEquals("body", readAscii(connection));
   }
 
   /**