Separate region data builder from preload supplier.

R=roubert@google.com

Review URL: https://codereview.appspot.com/101830044

git-svn-id: http://libaddressinput.googlecode.com/svn/trunk@256 38ededc0-08b8-5190-f2ac-b31f878777ad

7 files changed, 337 insertions, 187 deletions

diff --git a/cpp/include/libaddressinput/preload_supplier.h b/cpp/include/libaddressinput/preload_supplier.h
index 7226126..447911f 100644
--- a/cpp/include/libaddressinput/preload_supplier.h
+++ b/cpp/include/libaddressinput/preload_supplier.h
@@ -29,7 +29,6 @@ namespace addressinput {
 
 class Downloader;
 class LookupKey;
-class RegionData;
 class Retriever;
 class Rule;
 class Storage;
@@ -83,52 +82,15 @@ class PreloadSupplier : public Supplier {
   bool IsLoaded(const std::string& region_code) const;
   bool IsPending(const std::string& region_code) const;
 
-  // Returns a tree of administrative subdivisions for the |region_code|.
-  // Examples:
-  //   US with en-US UI language.
-  //   |______________________
-  //   |           |          |
-  //   v           v          v
-  // AL:Alabama  AK:Alaska  AS:American Samoa  ...
-  //
-  //   KR with ko-Latn UI language.
-  //   |______________________________________
-  //       |               |                  |
-  //       v               v                  v
-  // 강원도:Gangwon  경기도:Gyeonggi  경상남도:Gyeongnam  ...
-  //
-  //   KR with ko-KR UI language.
-  //   |_______________________________
-  //       |            |              |
-  //       v            v              v
-  // 강원도:강원  경기도:경기  경상남도:경남  ...
-  //
-  // The BCP 47 |ui_language_tag| is used to choose the best supported language
-  // tag for this region (assigned to |best_region_tree_language_tag|). For
-  // example, Canada has both English and French names for its administrative
-  // subdivisions. If the UI language is French, then the French names are used.
-  // The |best_region_tree_language_tag| value may be an empty string.
-  //
-  // Should be called only if IsLoaded(region_code) returns true. The
-  // |best_region_tree_language_tag| parameter should not be NULL.
-  const RegionData& BuildRegionTree(const std::string& region_code,
-                                    const std::string& ui_language_tag,
-                                    std::string* best_region_tree_language_tag);
-
  private:
-  typedef std::map<std::string, const RegionData*> LanguageRegionMap;
-  typedef std::map<std::string, LanguageRegionMap*> RegionCodeDataMap;
-
   bool GetRuleHierarchy(const LookupKey& lookup_key,
                         RuleHierarchy* hierarchy) const;
   bool IsLoadedKey(const std::string& key) const;
   bool IsPendingKey(const std::string& key) const;
-  static std::string KeyFromRegionCode(const std::string& region_code);
 
   const scoped_ptr<const Retriever> retriever_;
   std::set<std::string> pending_;
   std::map<std::string, const Rule*> rule_cache_;
-  RegionCodeDataMap region_data_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(PreloadSupplier);
 };
diff --git a/cpp/include/libaddressinput/region_data_builder.h b/cpp/include/libaddressinput/region_data_builder.h
new file mode 100644
index 0000000..906ca36
--- /dev/null
+++ b/cpp/include/libaddressinput/region_data_builder.h
@@ -0,0 +1,80 @@
+// Copyright (C) 2014 Google Inc.
+//
+// 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.
+
+#ifndef I18N_ADDRESSINPUT_REGION_DATA_BUILDER_H_
+#define I18N_ADDRESSINPUT_REGION_DATA_BUILDER_H_
+
+#include <libaddressinput/util/basictypes.h>
+
+#include <map>
+#include <string>
+
+namespace i18n {
+namespace addressinput {
+
+class PreloadSupplier;
+class RegionData;
+
+class RegionDataBuilder {
+ public:
+  // Does not take ownership of |supplier|, which should not be NULL.
+  explicit RegionDataBuilder(PreloadSupplier* supplier);
+  ~RegionDataBuilder();
+
+  // Returns a tree of administrative subdivisions for the |region_code|.
+  // Examples:
+  //   US with en-US UI language.
+  //   |______________________
+  //   |           |          |
+  //   v           v          v
+  // AL:Alabama  AK:Alaska  AS:American Samoa  ...
+  //
+  //   KR with ko-Latn UI language.
+  //   |______________________________________
+  //       |               |                  |
+  //       v               v                  v
+  // 강원도:Gangwon  경기도:Gyeonggi  경상남도:Gyeongnam  ...
+  //
+  //   KR with ko-KR UI language.
+  //   |_______________________________
+  //       |            |              |
+  //       v            v              v
+  // 강원도:강원  경기도:경기  경상남도:경남  ...
+  //
+  // The BCP 47 |ui_language_tag| is used to choose the best supported language
+  // tag for this region (assigned to |best_region_tree_language_tag|). For
+  // example, Canada has both English and French names for its administrative
+  // subdivisions. If the UI language is French, then the French names are used.
+  // The |best_region_tree_language_tag| value may be an empty string.
+  //
+  // Should be called only if supplier->IsLoaded(region_code) returns true. The
+  // |best_region_tree_language_tag| parameter should not be NULL.
+  const RegionData& Build(const std::string& region_code,
+                          const std::string& ui_language_tag,
+                          std::string* best_region_tree_language_tag);
+
+ private:
+  typedef std::map<std::string, const RegionData*> LanguageRegionMap;
+  typedef std::map<std::string, LanguageRegionMap*> RegionCodeDataMap;
+
+  PreloadSupplier* const supplier_;  // Not owned.
+  RegionCodeDataMap cache_;
+
+  DISALLOW_COPY_AND_ASSIGN(RegionDataBuilder);
+};
+
+}  // namespace addressinput
+}  // namespace i18n
+
+#endif  // I18N_ADDRESSINPUT_REGION_DATA_BUILDER_H_
diff --git a/cpp/libaddressinput.gypi b/cpp/libaddressinput.gypi
index 62ebe88..f5e668c 100644
--- a/cpp/libaddressinput.gypi
+++ b/cpp/libaddressinput.gypi
@@ -32,6 +32,7 @@
       'src/post_box_matchers.cc',
       'src/preload_supplier.cc',
       'src/region_data.cc',
+      'src/region_data_builder.cc',
       'src/region_data_constants.cc',
       'src/retriever.cc',
       'src/rule.cc',
@@ -68,6 +69,7 @@
       'test/ondemand_supplier_test.cc',
       'test/post_box_matchers_test.cc',
       'test/preload_supplier_test.cc',
+      'test/region_data_builder_test.cc',
       'test/region_data_constants_test.cc',
       'test/region_data_test.cc',
       'test/retriever_test.cc',
diff --git a/cpp/src/preload_supplier.cc b/cpp/src/preload_supplier.cc
index 9504cc6..be438a2 100644
--- a/cpp/src/preload_supplier.cc
+++ b/cpp/src/preload_supplier.cc
@@ -17,7 +17,6 @@
 #include <libaddressinput/address_data.h>
 #include <libaddressinput/address_field.h>
 #include <libaddressinput/callback.h>
-#include <libaddressinput/region_data.h>
 #include <libaddressinput/supplier.h>
 #include <libaddressinput/util/basictypes.h>
 #include <libaddressinput/util/scoped_ptr.h>
@@ -134,58 +133,12 @@ class Helper {
   DISALLOW_COPY_AND_ASSIGN(Helper);
 };
 
-// Does not take ownership of |supplier| or |parent_region|, neither of which is
-// allowed to be NULL.
-void BuildRegionTreeRecursively(PreloadSupplier* supplier,
-                                const LookupKey& parent_key,
-                                RegionData* parent_region,
-                                const std::vector<std::string>& keys,
-                                bool prefer_latin_name) {
-  assert(supplier != NULL);
-  assert(parent_region != NULL);
-
-  LookupKey lookup_key;
-  for (std::vector<std::string>::const_iterator key_it = keys.begin();
-       key_it != keys.end(); ++key_it) {
-    lookup_key.FromLookupKey(parent_key, *key_it);
-    const Rule* rule = supplier->GetRule(lookup_key);
-    if (rule == NULL) {
-      return;
-    }
-    const std::string& local_name = rule->GetName().empty()
-        ? *key_it : rule->GetName();
-    const std::string& name =
-        prefer_latin_name && !rule->GetLatinName().empty()
-            ? rule->GetLatinName() : local_name;
-    RegionData* region = parent_region->AddSubRegion(*key_it, name);
-    if (!rule->GetSubKeys().empty()) {
-      BuildRegionTreeRecursively(supplier, lookup_key, region,
-                                 rule->GetSubKeys(), prefer_latin_name);
-    }
-  }
-}
-
-// Does not take ownership of |supplier|, which cannot be NULL. The caller owns
-// the result.
-RegionData* BuildRegion(PreloadSupplier* supplier,
-                        const std::string& region_code,
-                        const Language& language) {
-  assert(supplier != NULL);
-
+std::string KeyFromRegionCode(const std::string& region_code) {
   AddressData address;
   address.region_code = region_code;
-
   LookupKey lookup_key;
   lookup_key.FromAddress(address);
-
-  const Rule* const rule = supplier->GetRule(lookup_key);
-  assert(rule != NULL);
-
-  RegionData* region = new RegionData(region_code);
-  BuildRegionTreeRecursively(supplier, lookup_key, region,
-                             rule->GetSubKeys(), language.has_latin_script);
-
-  return region;
+  return lookup_key.ToKeyString(0);  // Zero depth = COUNTRY level.
 }
 
 }  // namespace
@@ -195,23 +148,12 @@ PreloadSupplier::PreloadSupplier(const std::string& validation_data_url,
                                  Storage* storage)
     : retriever_(new Retriever(validation_data_url, downloader, storage)),
       pending_(),
-      rule_cache_(),
-      region_data_cache_() {}
+      rule_cache_() {}
 
 PreloadSupplier::~PreloadSupplier() {
   for (std::map<std::string, const Rule*>::const_iterator
-       rule_it = rule_cache_.begin(); rule_it != rule_cache_.end(); ++rule_it) {
-    delete rule_it->second;
-  }
-
-  for (RegionCodeDataMap::const_iterator region_it = region_data_cache_.begin();
-       region_it != region_data_cache_.end(); ++region_it) {
-    for (LanguageRegionMap::const_iterator
-         language_it = region_it->second->begin();
-         language_it != region_it->second->end(); ++language_it) {
-      delete language_it->second;
-    }
-    delete region_it->second;
+       it = rule_cache_.begin(); it != rule_cache_.end(); ++it) {
+    delete it->second;
   }
 }
 
@@ -261,42 +203,6 @@ bool PreloadSupplier::IsPending(const std::string& region_code) const {
   return IsPendingKey(KeyFromRegionCode(region_code));
 }
 
-const RegionData& PreloadSupplier::BuildRegionTree(
-    const std::string& region_code,
-    const std::string& ui_language_tag,
-    std::string* best_region_tree_language_tag) {
-  assert(IsLoaded(region_code));
-  assert(best_region_tree_language_tag != NULL);
-
-  // Look up the region tree in cache first before building it.
-  RegionCodeDataMap::const_iterator region_it =
-      region_data_cache_.find(region_code);
-  if (region_it == region_data_cache_.end()) {
-    region_it = region_data_cache_.insert(
-        std::make_pair(region_code, new LanguageRegionMap)).first;
-  }
-
-  // No need to copy from default rule first, because only languages and Latin
-  // format are going to be used, which do not exist in the default rule.
-  Rule rule;
-  rule.ParseSerializedRule(RegionDataConstants::GetRegionData(region_code));
-  static const Language kUndefinedLanguage("und");
-  const Language& best_language = rule.GetLanguages().empty()
-      ? kUndefinedLanguage
-      : ChooseBestAddressLanguage(rule, Language(ui_language_tag));
-  *best_region_tree_language_tag = best_language.tag;
-
-  LanguageRegionMap::const_iterator language_it =
-      region_it->second->find(best_language.tag);
-  if (language_it == region_it->second->end()) {
-    language_it = region_it->second->insert(
-        std::make_pair(best_language.tag,
-                       BuildRegion(this, region_code, best_language))).first;
-  }
-
-  return *language_it->second;
-}
-
 bool PreloadSupplier::GetRuleHierarchy(const LookupKey& lookup_key,
                                        RuleHierarchy* hierarchy) const {
   assert(hierarchy != NULL);
@@ -328,14 +234,5 @@ bool PreloadSupplier::IsPendingKey(const std::string& key) const {
   return pending_.find(key) != pending_.end();
 }
 
-// static
-std::string PreloadSupplier::KeyFromRegionCode(const std::string& region_code) {
-  AddressData address;
-  address.region_code = region_code;
-  LookupKey lookup_key;
-  lookup_key.FromAddress(address);
-  return lookup_key.ToKeyString(0);  // Zero depth = COUNTRY level.
-}
-
 }  // namespace addressinput
 }  // namespace i18n
diff --git a/cpp/src/region_data_builder.cc b/cpp/src/region_data_builder.cc
new file mode 100644
index 0000000..82d223c
--- /dev/null
+++ b/cpp/src/region_data_builder.cc
@@ -0,0 +1,147 @@
+// Copyright (C) 2014 Google Inc.
+//
+// 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.
+
+#include <libaddressinput/region_data_builder.h>
+
+#include <libaddressinput/address_data.h>
+#include <libaddressinput/preload_supplier.h>
+#include <libaddressinput/region_data.h>
+
+#include <cassert>
+#include <cstddef>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "language.h"
+#include "lookup_key.h"
+#include "region_data_constants.h"
+#include "rule.h"
+
+namespace i18n {
+namespace addressinput {
+
+namespace {
+
+// Does not take ownership of |supplier| or |parent_region|, neither of which is
+// allowed to be NULL.
+void BuildRegionTreeRecursively(PreloadSupplier* supplier,
+                                const LookupKey& parent_key,
+                                RegionData* parent_region,
+                                const std::vector<std::string>& keys,
+                                bool prefer_latin_name) {
+  assert(supplier != NULL);
+  assert(parent_region != NULL);
+
+  LookupKey lookup_key;
+  for (std::vector<std::string>::const_iterator key_it = keys.begin();
+       key_it != keys.end(); ++key_it) {
+    lookup_key.FromLookupKey(parent_key, *key_it);
+    const Rule* rule = supplier->GetRule(lookup_key);
+    if (rule == NULL) {
+      return;
+    }
+    const std::string& local_name = rule->GetName().empty()
+        ? *key_it : rule->GetName();
+    const std::string& name =
+        prefer_latin_name && !rule->GetLatinName().empty()
+            ? rule->GetLatinName() : local_name;
+    RegionData* region = parent_region->AddSubRegion(*key_it, name);
+    if (!rule->GetSubKeys().empty()) {
+      BuildRegionTreeRecursively(supplier, lookup_key, region,
+                                 rule->GetSubKeys(), prefer_latin_name);
+    }
+  }
+}
+
+// Does not take ownership of |supplier|, which cannot be NULL. The caller owns
+// the result.
+RegionData* BuildRegion(PreloadSupplier* supplier,
+                        const std::string& region_code,
+                        const Language& language) {
+  assert(supplier != NULL);
+
+  AddressData address;
+  address.region_code = region_code;
+
+  LookupKey lookup_key;
+  lookup_key.FromAddress(address);
+
+  const Rule* const rule = supplier->GetRule(lookup_key);
+  assert(rule != NULL);
+
+  RegionData* region = new RegionData(region_code);
+  BuildRegionTreeRecursively(supplier, lookup_key, region,
+                             rule->GetSubKeys(), language.has_latin_script);
+
+  return region;
+}
+
+}  // namespace
+
+RegionDataBuilder::RegionDataBuilder(PreloadSupplier* supplier)
+    : supplier_(supplier),
+      cache_() {
+  assert(supplier_ != NULL);
+}
+
+RegionDataBuilder::~RegionDataBuilder() {
+  for (RegionCodeDataMap::const_iterator region_it = cache_.begin();
+       region_it != cache_.end(); ++region_it) {
+    for (LanguageRegionMap::const_iterator
+         language_it = region_it->second->begin();
+         language_it != region_it->second->end(); ++language_it) {
+      delete language_it->second;
+    }
+    delete region_it->second;
+  }
+}
+
+const RegionData& RegionDataBuilder::Build(
+    const std::string& region_code,
+    const std::string& ui_language_tag,
+    std::string* best_region_tree_language_tag) {
+  assert(supplier_->IsLoaded(region_code));
+  assert(best_region_tree_language_tag != NULL);
+
+  // Look up the region tree in cache first before building it.
+  RegionCodeDataMap::const_iterator region_it = cache_.find(region_code);
+  if (region_it == cache_.end()) {
+    region_it =
+        cache_.insert(std::make_pair(region_code, new LanguageRegionMap)).first;
+  }
+
+  // No need to copy from default rule first, because only languages and Latin
+  // format are going to be used, which do not exist in the default rule.
+  Rule rule;
+  rule.ParseSerializedRule(RegionDataConstants::GetRegionData(region_code));
+  static const Language kUndefinedLanguage("und");
+  const Language& best_language = rule.GetLanguages().empty()
+      ? kUndefinedLanguage
+      : ChooseBestAddressLanguage(rule, Language(ui_language_tag));
+  *best_region_tree_language_tag = best_language.tag;
+
+  LanguageRegionMap::const_iterator language_it =
+      region_it->second->find(best_language.tag);
+  if (language_it == region_it->second->end()) {
+    language_it = region_it->second->insert(std::make_pair(
+        best_language.tag,
+        BuildRegion(supplier_, region_code, best_language))).first;
+  }
+
+  return *language_it->second;
+}
+
+}  // namespace addressinput
+}  // namespace i18n
diff --git a/cpp/test/preload_supplier_test.cc b/cpp/test/preload_supplier_test.cc
index 3ddbc34..b812ef1 100644
--- a/cpp/test/preload_supplier_test.cc
+++ b/cpp/test/preload_supplier_test.cc
@@ -17,7 +17,6 @@
 #include <libaddressinput/address_data.h>
 #include <libaddressinput/callback.h>
 #include <libaddressinput/null_storage.h>
-#include <libaddressinput/region_data.h>
 #include <libaddressinput/util/basictypes.h>
 #include <libaddressinput/util/scoped_ptr.h>
 
@@ -38,7 +37,6 @@ using i18n::addressinput::FakeDownloader;
 using i18n::addressinput::LookupKey;
 using i18n::addressinput::NullStorage;
 using i18n::addressinput::PreloadSupplier;
-using i18n::addressinput::RegionData;
 using i18n::addressinput::Rule;
 using i18n::addressinput::scoped_ptr;
 
@@ -48,22 +46,20 @@ class PreloadSupplierTest : public testing::Test {
       : supplier_(FakeDownloader::kFakeAggregateDataUrl,
                   new FakeDownloader,
                   new NullStorage),
-        loaded_callback_(BuildCallback(this, &PreloadSupplierTest::OnLoaded)),
-        best_language_() {}
+        loaded_callback_(BuildCallback(this, &PreloadSupplierTest::OnLoaded)) {}
 
-  ~PreloadSupplierTest() {}
+  virtual ~PreloadSupplierTest() {}
 
   PreloadSupplier supplier_;
   scoped_ptr<PreloadSupplier::Callback> loaded_callback_;
-  std::string best_language_;
 
  private:
   void OnLoaded(bool success,
                 const std::string& region_code,
                 const int& num_rules) {
-    EXPECT_TRUE(success);
-    EXPECT_FALSE(region_code.empty());
-    EXPECT_LT(0, num_rules);
+    ASSERT_TRUE(success);
+    ASSERT_FALSE(region_code.empty());
+    ASSERT_LT(0, num_rules);
     ASSERT_TRUE(supplier_.IsLoaded(region_code));
   }
 
@@ -127,36 +123,4 @@ TEST_F(PreloadSupplierTest, GetTooPreciseRule) {
   EXPECT_TRUE(rule == NULL);
 }
 
-TEST_F(PreloadSupplierTest, BuildUsRegionTree) {
-  supplier_.LoadRules("US", *loaded_callback_);
-  const RegionData& tree =
-      supplier_.BuildRegionTree("US", "en-US", &best_language_);
-  EXPECT_FALSE(tree.sub_regions().empty());
-}
-
-TEST_F(PreloadSupplierTest, BuildCnRegionTree) {
-  supplier_.LoadRules("CN", *loaded_callback_);
-  const RegionData& tree =
-      supplier_.BuildRegionTree("CN", "zh-Hans", &best_language_);
-  ASSERT_FALSE(tree.sub_regions().empty());
-  EXPECT_FALSE(tree.sub_regions().front()->sub_regions().empty());
-}
-
-TEST_F(PreloadSupplierTest, BuildChRegionTree) {
-  supplier_.LoadRules("CH", *loaded_callback_);
-  const RegionData& tree =
-      supplier_.BuildRegionTree("CH", "de-CH", &best_language_);
-  // Although "CH" has information for its administrative divisions, the
-  // administrative area field is not used, which results in an empty tree of
-  // sub-regions.
-  EXPECT_TRUE(tree.sub_regions().empty());
-}
-
-TEST_F(PreloadSupplierTest, BuildZwRegionTree) {
-  supplier_.LoadRules("ZW", *loaded_callback_);
-  const RegionData& tree =
-      supplier_.BuildRegionTree("ZW", "en-ZW", &best_language_);
-  EXPECT_TRUE(tree.sub_regions().empty());
-}
-
 }  // namespace
diff --git a/cpp/test/region_data_builder_test.cc b/cpp/test/region_data_builder_test.cc
new file mode 100644
index 0000000..088a73e
--- /dev/null
+++ b/cpp/test/region_data_builder_test.cc
@@ -0,0 +1,98 @@
+// Copyright (C) 2014 Google Inc.
+//
+// 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.
+
+#include <libaddressinput/region_data_builder.h>
+
+#include <libaddressinput/callback.h>
+#include <libaddressinput/null_storage.h>
+#include <libaddressinput/preload_supplier.h>
+#include <libaddressinput/region_data.h>
+#include <libaddressinput/util/basictypes.h>
+#include <libaddressinput/util/scoped_ptr.h>
+
+#include "fake_downloader.h"
+
+#include <string>
+
+#include <gtest/gtest.h>
+
+namespace {
+
+using i18n::addressinput::BuildCallback;
+using i18n::addressinput::FakeDownloader;
+using i18n::addressinput::NullStorage;
+using i18n::addressinput::PreloadSupplier;
+using i18n::addressinput::RegionData;
+using i18n::addressinput::RegionDataBuilder;
+using i18n::addressinput::scoped_ptr;
+
+class RegionDataBuilderTest : public testing::Test {
+ protected:
+  RegionDataBuilderTest()
+      : supplier_(FakeDownloader::kFakeAggregateDataUrl,
+                  new FakeDownloader,
+                  new NullStorage),
+        builder_(&supplier_),
+        loaded_callback_(BuildCallback(this, &RegionDataBuilderTest::OnLoaded)),
+        best_language_() {}
+
+  virtual ~RegionDataBuilderTest() {}
+
+  PreloadSupplier supplier_;
+  RegionDataBuilder builder_;
+  scoped_ptr<PreloadSupplier::Callback> loaded_callback_;
+  std::string best_language_;
+
+ private:
+  void OnLoaded(bool success,
+                const std::string& region_code,
+                const int& num_rules) {
+    ASSERT_TRUE(success);
+    ASSERT_FALSE(region_code.empty());
+    ASSERT_LT(0, num_rules);
+    ASSERT_TRUE(supplier_.IsLoaded(region_code));
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(RegionDataBuilderTest);
+};
+
+TEST_F(RegionDataBuilderTest, BuildUsRegionTree) {
+  supplier_.LoadRules("US", *loaded_callback_);
+  const RegionData& tree = builder_.Build("US", "en-US", &best_language_);
+  EXPECT_FALSE(tree.sub_regions().empty());
+}
+
+TEST_F(RegionDataBuilderTest, BuildCnRegionTree) {
+  supplier_.LoadRules("CN", *loaded_callback_);
+  const RegionData& tree = builder_.Build("CN", "zh-Hans", &best_language_);
+  ASSERT_FALSE(tree.sub_regions().empty());
+  EXPECT_FALSE(tree.sub_regions().front()->sub_regions().empty());
+}
+
+TEST_F(RegionDataBuilderTest, BuildChRegionTree) {
+  supplier_.LoadRules("CH", *loaded_callback_);
+  const RegionData& tree = builder_.Build("CH", "de-CH", &best_language_);
+  // Although "CH" has information for its administrative divisions, the
+  // administrative area field is not used, which results in an empty tree of
+  // sub-regions.
+  EXPECT_TRUE(tree.sub_regions().empty());
+}
+
+TEST_F(RegionDataBuilderTest, BuildZwRegionTree) {
+  supplier_.LoadRules("ZW", *loaded_callback_);
+  const RegionData& tree = builder_.Build("ZW", "en-ZW", &best_language_);
+  EXPECT_TRUE(tree.sub_regions().empty());
+}
+
+}  // namespace