Create a nicer interface for base::mac::GetValueFromDictionary

base/mac/foundation_util_unittest.mm

 // 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 "base/mac/foundation_util.h"
 
+#include "base/basictypes.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(FoundationUtilTest, CFCast) {
   // Build out the CF types to be tested as empty containers.
   base::mac::ScopedCFTypeRef<CFTypeRef> test_array(
       CFArrayCreate(NULL, NULL, 0, &kCFTypeArrayCallBacks));
   base::mac::ScopedCFTypeRef<CFTypeRef> test_array_mutable(
       CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks));
@@ skipping 251 matching lines @@
   // ObjCCastStrict: Giving a nil provides a nil.
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSArray>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSData>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSDate>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSDictionary>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSNull>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSNumber>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSSet>(nil));
   EXPECT_FALSE(base::mac::ObjCCastStrict<NSString>(nil));
 }
+
+TEST(FoundationUtilTest, GetValueFromDictionary) {
+  int one = 1, two = 2, three = 3;
+
+  base::mac::ScopedCFTypeRef<CFNumberRef> cf_one(
+      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &one));
+  base::mac::ScopedCFTypeRef<CFNumberRef> cf_two(
+      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &two));
+  base::mac::ScopedCFTypeRef<CFNumberRef> cf_three(
+      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &three));
+
+  CFStringRef keys[] = { CFSTR("one"), CFSTR("two"), CFSTR("three") };
+  CFNumberRef values[] = { cf_one, cf_two, cf_three };
+
+  COMPILE_ASSERT(arraysize(keys) == arraysize(values),
+                 keys_and_values_arraysizes_are_different);
+
+  base::mac::ScopedCFTypeRef<CFDictionaryRef> test_dict(
+      CFDictionaryCreate(kCFAllocatorDefault,
+                         (const void**)keys,

[Mark Mentovai, 2011/11/14 22:09:42]

Can’t these both be C++-style casts?

reinterpret_cast<const void**>(keys),
reinterpret_cast<const void**>(values),

The style guide has a very strong preference for explicit C++-style casts over
“anything goes” C-style ones.

See
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Castin...
.

+                         (const void**)values,
+                         arraysize(values),
+                         &kCFCopyStringDictionaryKeyCallBacks,
+                         &kCFTypeDictionaryValueCallBacks));
+
+  // base::mac::GetValueFromDictionary<>(_, _) should produce the correct
+  // expected output.
+  EXPECT_EQ(values[0],
+            base::mac::GetValueFromDictionary<CFNumberRef>(test_dict,
+                                                           CFSTR("one")));
+  EXPECT_EQ(values[1],
+            base::mac::GetValueFromDictionary<CFNumberRef>(test_dict,
+                                                           CFSTR("two")));
+  EXPECT_EQ(values[2],
+            base::mac::GetValueFromDictionary<CFNumberRef>(test_dict,
+                                                           CFSTR("three")));
+
+  // Bad input should produce bad output.
+  EXPECT_FALSE(base::mac::GetValueFromDictionary<CFNumberRef>(test_dict,
+                                                              CFSTR("four")));
+  EXPECT_FALSE(base::mac::GetValueFromDictionary<CFStringRef>(test_dict,
+                                                              CFSTR("one")));
+}