Testing: Fixed printing FilePaths when a test fails comparing them.

base/files/file_path.h

 // 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.
 
 // FilePath is a container for pathnames stored in a platform's native string
 // type, providing containers for manipulation in according with the
 // platform's conventions for pathnames.  It supports the following path
 // types:
 //
 //                   POSIX            Windows
@@ skipping 415 matching lines @@
   // Remove trailing separators from this object.  If the path is absolute, it
   // will never be stripped any more than to refer to the absolute root
   // directory, so "////" will become "/", not "".  A leading pair of
   // separators is never stripped, to support alternate roots.  This is used to
   // support UNC paths on Windows.
   void StripTrailingSeparatorsInternal();
 
   StringType path_;
 };
 
+// This is required by googletest to print a readable output on test failures.
+BASE_EXPORT extern void PrintTo(const FilePath& path, std::ostream* out);

[danakj, 2015/05/22 20:59:23]

While you're here, including std::ostream everywhere isn't free, and linking
this into production code for gtest isn't quite right.

James did something nice for our gfx types to support PrintTo in tests, but not
in prod:
https://chromium.googlesource.com/chromium/src/+/a109fd05fac9af35d219de6e4285...

Can we do something like that for this? (ie use isofwd only and move the defn to
a test build target.)

[Matt Giuca, 2015/05/25 03:40:15]

Done (moved to test_support_base), but...

On 2015/05/22 20:59:23, danakj wrote:
I'm confused about where std::ostream is coming from. I went to remove "#include
<iostream>" but it wasn't there... does that mean one of the other header files
is including it?

This means regardless of whether I do this change, won't we still be paying the
cost of iostream? (I'm unsure exactly what the cost is... is it having to
process the iostream headers in every file that includes file_path.h? Or is it
linking in the ostream code at all?)

[Matt Giuca, 2015/05/25 05:54:01]

Sorry, by <iostream> I meant <ostream>.

+
 }  // namespace base
 
-// This is required by googletest to print a readable output on test failures.
-BASE_EXPORT extern void PrintTo(const base::FilePath& path, std::ostream* out);
-
 // Macros for string literal initialization of FilePath::CharType[], and for
 // using a FilePath::CharType[] in a printf-style format string.
 #if defined(OS_POSIX)
 #define FILE_PATH_LITERAL(x) x
 #define PRFilePath "s"
 #elif defined(OS_WIN)
 #define FILE_PATH_LITERAL(x) L ## x
 #define PRFilePath "ls"
 #endif  // OS_WIN
 
 // Provide a hash function so that hash_sets and maps can contain FilePath
 // objects.
 namespace BASE_HASH_NAMESPACE {
 
 template<>
 struct hash<base::FilePath> {
   size_t operator()(const base::FilePath& f) const {
     return hash<base::FilePath::StringType>()(f.value());
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 
 #endif  // BASE_FILES_FILE_PATH_H_