Add unit-tests for SingleRequestHostResolver.

net/base/single_request_host_resolver_unittest.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/base/single_request_host_resolver.h"
+
+#include "net/base/mock_host_resolver.h"
+#include "net/base/net_errors.h"
+#include "net/base/test_completion_callback.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace {
+
+// Helper class used by SingleRequestHostResolverTest.Cancel test.
+// It checks that only one request is outstanding at a time, and that
+// it is cancelled before the class is destroyed.
+class HangingHostResolver : public HostResolver {
+ public:
+  HangingHostResolver() : outstanding_request_(NULL) {}
+
+  virtual ~HangingHostResolver() {
+    EXPECT_TRUE(!has_outstanding_request());
+  }
+
+  bool has_outstanding_request() const {
+    return outstanding_request_ != NULL;
+  }
+
+  virtual int Resolve(const RequestInfo& info,
+                      AddressList* addresses,
+                      CompletionCallback* callback,
+                      RequestHandle* out_req,
+                      const BoundNetLog& net_log) {
+    EXPECT_FALSE(has_outstanding_request());
+    outstanding_request_ = reinterpret_cast<RequestHandle>(0x1234);
+    *out_req = outstanding_request_;
+
+    // Never complete this request! Caller is expected to cancel it
+    // before destroying the resolver.
+    return ERR_IO_PENDING;
+  }
+
+  virtual void CancelRequest(RequestHandle req) {
+    EXPECT_TRUE(has_outstanding_request());
+    EXPECT_EQ(req, outstanding_request_);
+    outstanding_request_ = NULL;
+  }
+
+  virtual void AddObserver(Observer* observer) {
+    FAIL();
+  }
+
+  virtual void RemoveObserver(Observer* observer) {
+    FAIL();
+  }
+
+ private:
+  RequestHandle outstanding_request_;
+
+  DISALLOW_COPY_AND_ASSIGN(HangingHostResolver);
+};
+
+// Test that a regular end-to-end lookup returns the expected result.
+TEST(SingleRequestHostResolverTest, NormalResolve) {
+  // Create a host resolver dependency that returns address "199.188.1.166"
+  // for resolutions of "watsup".
+  MockHostResolver resolver;
+  resolver.rules()->AddIPLiteralRule("watsup", "199.188.1.166", "");
+
+  SingleRequestHostResolver single_request_resolver(&resolver);
+
+  // Resolve "watsup:90" using our SingleRequestHostResolver.
+  AddressList addrlist;
+  TestCompletionCallback callback;
+  HostResolver::RequestInfo request(HostPortPair("watsup", 90));
+  int rv = single_request_resolver.Resolve(
+      request, &addrlist, &callback, BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // Verify that the result is what we specified in the MockHostResolver.
+  EXPECT_EQ("199.188.1.166", NetAddressToString(addrlist.head()));
+}
+
+// Test that the Cancel() method cancels any outstanding request.
+TEST(SingleRequestHostResolverTest, Cancel) {
+  HangingHostResolver resolver;
+
+  {
+    SingleRequestHostResolver single_request_resolver(&resolver);
+
+    // Resolve "watsup:90" using our SingleRequestHostResolver.
+    AddressList addrlist;
+    TestCompletionCallback callback;
+    HostResolver::RequestInfo request(HostPortPair("watsup", 90));
+    int rv = single_request_resolver.Resolve(
+        request, &addrlist, &callback, BoundNetLog());
+    EXPECT_EQ(ERR_IO_PENDING, rv);
+    EXPECT_TRUE(resolver.has_outstanding_request());
+  }
+
+  // Now that the SingleRequestHostResolver has been destroyed, the
+  // in-progress request should have been aborted.
+  EXPECT_FALSE(resolver.has_outstanding_request());
+}
+
+// Test that the Cancel() method is a no-op when there is no outstanding
+// request.
+TEST(SingleRequestHostResolverTest, CancelWhileNoPendingRequest) {
+  HangingHostResolver resolver;
+  SingleRequestHostResolver single_request_resolver(&resolver);
+  single_request_resolver.Cancel();
+
+  // To pass, HangingHostResolver should not have received a cancellation
+  // request (since there is nothing to cancel). If it does, it will crash.
+}
+
+} // namespace
+
+}  // namespace net