Add unit test for functionality added to ReplaceStringPlaceholders in r57966.

TEST=base_unittests --gtest_filter=StringUtilTest.ReplaceStringPlaceholders*

Review URL: http://codereview.chromium.org/3266013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@58047 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 12 insertions, 2 deletions

diff --git a/base/string_util.h b/base/string_util.h
index ae8b93c..ca028e1 100644
--- a/base/string_util.h
+++ b/base/string_util.h
@@ -579,8 +579,9 @@ void SplitStringAlongWhitespace(const std::string& str,
                                 std::vector<std::string>* result);
 
 // Replace $1-$2-$3..$9 in the format string with |a|-|b|-|c|..|i| respectively.
-// Additionally, $$ is replaced by $. The offsets parameter here can
-// be NULL. This only allows you to use up to nine replacements.
+// Additionally, any number of consecutive '$' characters is replaced by that
+// number less one. Eg $$->$, $$$->$$, etc. The offsets parameter here can be
+// NULL. This only allows you to use up to nine replacements.
 string16 ReplaceStringPlaceholders(const string16& format_string,
                                    const std::vector<string16>& subst,
                                    std::vector<size_t>* offsets);
diff --git a/base/string_util_unittest.cc b/base/string_util_unittest.cc
index 7bdacea..b317d83 100644
--- a/base/string_util_unittest.cc
+++ b/base/string_util_unittest.cc
@@ -1022,6 +1022,15 @@ TEST(StringUtilTest, StdStringReplaceStringPlaceholders) {
   EXPECT_EQ(formatted, "9aa,8bb,7cc,6dd,5ee,4ff,3gg,2hh,1ii");
 }
 
+TEST(StringUtilTest, ReplaceStringPlaceholdersConsecutiveDollarSigns) {
+  std::vector<std::string> subst;
+  subst.push_back("a");
+  subst.push_back("b");
+  subst.push_back("c");
+  EXPECT_EQ(ReplaceStringPlaceholders("$$1 $$$2 $$$$3", subst, NULL),
+            "$1 $$2 $$$3");
+}
+
 TEST(StringUtilTest, SplitStringAlongWhitespace) {
   struct TestData {
     const std::wstring input;