Fast-fail WPAD detection.

net/proxy/proxy_script_decider_unittest.cc

 // Copyright (c) 2012 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 <vector>
 
 #include "base/bind.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
 #include "net/base/net_log_unittest.h"
 #include "net/base/test_completion_callback.h"
+#include "net/dns/mock_host_resolver.h"
 #include "net/proxy/dhcp_proxy_script_fetcher.h"
 #include "net/proxy/proxy_config.h"
 #include "net/proxy/proxy_resolver.h"
 #include "net/proxy/proxy_script_decider.h"
 #include "net/proxy/proxy_script_fetcher.h"
+#include "net/url_request/url_request_context.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 namespace {
 
 enum Error {
   kFailedDownloading = -100,
   kFailedParsing = ERR_PAC_SCRIPT_FAILED,
 };
 
@@ skipping 54 matching lines @@
     return rules_[0];
   }
 
  private:
   typedef std::vector<Rule> RuleList;
   RuleList rules_;
 };
 
 class RuleBasedProxyScriptFetcher : public ProxyScriptFetcher {
  public:
-  explicit RuleBasedProxyScriptFetcher(const Rules* rules) : rules_(rules) {}
+  explicit RuleBasedProxyScriptFetcher(const Rules* rules)
+      : rules_(rules), request_context_(NULL) {}
+
+  virtual void SetRequestContext(URLRequestContext* context) {
+    request_context_ = context;
+  }
 
   // ProxyScriptFetcher implementation.
   virtual int Fetch(const GURL& url,
                     base::string16* text,
                     const CompletionCallback& callback) OVERRIDE {
     const Rules::Rule& rule = rules_->GetRuleByUrl(url);
     int rv = rule.fetch_error;
     EXPECT_NE(ERR_UNEXPECTED, rv);
     if (rv == OK)
       *text = rule.text();
     return rv;
   }
 
   virtual void Cancel() OVERRIDE {}
 
-  virtual URLRequestContext* GetRequestContext() const OVERRIDE { return NULL; }
+  virtual URLRequestContext* GetRequestContext() const OVERRIDE {
+    return request_context_;
+  }
 
  private:
   const Rules* rules_;
+  URLRequestContext* request_context_;
 };
 
 // Succeed using custom PAC script.
 TEST(ProxyScriptDeciderTest, CustomPacSucceeds) {
   Rules rules;
   RuleBasedProxyScriptFetcher fetcher(&rules);
   DoNothingDhcpProxyScriptFetcher dhcp_fetcher;
 
   ProxyConfig config;
   config.set_pac_url(GURL("http://custom/proxy.pac"));
@@ skipping 110 matching lines @@
   TestCompletionCallback callback;
   ProxyScriptDecider decider(&fetcher, &dhcp_fetcher, NULL);
   EXPECT_EQ(OK, decider.Start(
       config, base::TimeDelta(), true, callback.callback()));
   EXPECT_EQ(rule.text(), decider.script_data()->utf16());
 
   EXPECT_TRUE(decider.effective_config().has_pac_url());
   EXPECT_EQ(rule.url, decider.effective_config().pac_url());
 }
 
+class ProxyScriptDeciderQuickCheckTest : public ::testing::Test {
+ public:
+  ProxyScriptDeciderQuickCheckTest()
+      : rule_(rules_.AddSuccessRule("http://wpad/wpad.dat")),
+        fetcher_(&rules_) { }
+
+  virtual void SetUp() OVERRIDE {
+    request_context_.set_host_resolver(&resolver_);
+    fetcher_.SetRequestContext(&request_context_);
+    config_.set_auto_detect(true);
+    decider_.reset(new ProxyScriptDecider(&fetcher_, &dhcp_fetcher_, NULL));
+  }
+
+  int StartDecider() {
+    return decider_->Start(config_, base::TimeDelta(), true,
+                            callback_.callback());
+  }
+
+ protected:
+  scoped_ptr<ProxyScriptDecider> decider_;
+  MockHostResolver resolver_;
+  Rules rules_;
+  Rules::Rule rule_;
+  TestCompletionCallback callback_;
+
+ private:
+  URLRequestContext request_context_;
+
+  RuleBasedProxyScriptFetcher fetcher_;
+  DoNothingDhcpProxyScriptFetcher dhcp_fetcher_;
+
+  ProxyConfig config_;
+};
+
+// Fails if a synchronous DNS lookup success for wpad causes QuickCheck to fail.

[szym, 2013/09/11 21:29:21]

The common practice, at least in net/ and certainly within this file is that the
comment explains the asserted component behavior rather than what the test does,
i.e., this should be 

// QuickCheck passes if DNS lookup for wpad succeeds synchronously.

+TEST_F(ProxyScriptDeciderQuickCheckTest, SyncSuccess) {
+  resolver_.set_synchronous_mode(true);
+  resolver_.rules()->AddRule("wpad", "1.2.3.4");
+
+  EXPECT_EQ(OK, StartDecider());
+  EXPECT_EQ(rule_.text(), decider_->script_data()->utf16());
+
+  EXPECT_TRUE(decider_->effective_config().has_pac_url());
+  EXPECT_EQ(rule_.url, decider_->effective_config().pac_url());
+}
+
+// Fails if an asynchronous DNS lookup success for wpad causes QuickCheck to
+// fail.
+TEST_F(ProxyScriptDeciderQuickCheckTest, AsyncSuccess) {
+  resolver_.set_ondemand_mode(true);
+  resolver_.rules()->AddRule("wpad", "1.2.3.4");
+
+  EXPECT_EQ(ERR_IO_PENDING, StartDecider());
+  ASSERT_TRUE(resolver_.has_pending_requests());
+  resolver_.ResolveAllPending();
+  callback_.WaitForResult();
+  EXPECT_FALSE(resolver_.has_pending_requests());
+  EXPECT_EQ(rule_.text(), decider_->script_data()->utf16());
+  EXPECT_TRUE(decider_->effective_config().has_pac_url());
+  EXPECT_EQ(rule_.url, decider_->effective_config().pac_url());
+}
+
+// Fails if an asynchronous DNS lookup failure (i.e. an NXDOMAIN) still causes
+// ProxyScriptDecider to yield a PAC URL.
+TEST_F(ProxyScriptDeciderQuickCheckTest, AsyncFail) {
+  resolver_.set_ondemand_mode(true);
+  resolver_.rules()->AddSimulatedFailure("wpad");
+  EXPECT_EQ(ERR_IO_PENDING, StartDecider());
+  ASSERT_TRUE(resolver_.has_pending_requests());
+  resolver_.ResolveAllPending();
+  callback_.WaitForResult();
+  EXPECT_FALSE(decider_->effective_config().has_pac_url());
+}
+
+// Fails if a DNS lookup timeout either causes ProxyScriptDecider to yield a PAC
+// URL or causes ProxyScriptDecider not to cancel its pending resolution.
+TEST_F(ProxyScriptDeciderQuickCheckTest, AsyncTimeout) {
+  resolver_.set_ondemand_mode(true);
+  EXPECT_EQ(ERR_IO_PENDING, StartDecider());
+  ASSERT_TRUE(resolver_.has_pending_requests());
+  callback_.WaitForResult();

[szym, 2013/09/11 21:29:21]

WaitForResult returns the neterror passed to the CompletionCallback, so this
should be wrapped in EXPECT_EQ(ERR_NAME_NOT_RESOLVED, ...)

+  EXPECT_FALSE(resolver_.has_pending_requests());
+  EXPECT_FALSE(decider_->effective_config().has_pac_url());
+}
+
 // Fails at WPAD (downloading), but succeeds in choosing the custom PAC.
 TEST(ProxyScriptDeciderTest, AutodetectFailCustomSuccess1) {
   Rules rules;
   RuleBasedProxyScriptFetcher fetcher(&rules);
   DoNothingDhcpProxyScriptFetcher dhcp_fetcher;
 
   ProxyConfig config;
   config.set_auto_detect(true);
   config.set_pac_url(GURL("http://custom/proxy.pac"));
 
@@ skipping 334 matching lines @@
 
   // Run the message loop to let the DHCP fetch complete and post the results
   // back. Before the fix linked to above, this would try to invoke on
   // the callback object provided by ProxyScriptDecider after it was
   // no longer valid.
   base::MessageLoop::current()->RunUntilIdle();
 }
 
 }  // namespace
 }  // namespace net