Add StartsWithIgnoreCase/EndsWithIgnoreCase.

This has come up a couple of times now.

Bug: wanted as part of http://b/32094640
Test: ran tests
Change-Id: I51b67074b7ddeedd771d7be9651ba33e05491b33

3 files changed, 94 insertions, 11 deletions

diff --git a/base/include/android-base/strings.h b/base/include/android-base/strings.h
index 69781cd40..b8a92896a 100644
--- a/base/include/android-base/strings.h
+++ b/base/include/android-base/strings.h
@@ -58,9 +58,11 @@ extern template std::string Join(const std::vector<const char*>&, const std::str
 
 // Tests whether 's' starts with 'prefix'.
 bool StartsWith(const std::string& s, const char* prefix);
+bool StartsWithIgnoreCase(const std::string& s, const char* prefix);
 
 // Tests whether 's' ends with 'suffix'.
 bool EndsWith(const std::string& s, const char* suffix);
+bool EndsWithIgnoreCase(const std::string& s, const char* suffix);
 
 }  // namespace base
 }  // namespace android
diff --git a/base/strings.cpp b/base/strings.cpp
index b8775df21..7a94ad78c 100644
--- a/base/strings.cpp
+++ b/base/strings.cpp
@@ -87,17 +87,29 @@ template std::string Join(const std::vector<std::string>&, const std::string&);
 template std::string Join(const std::vector<const char*>&, const std::string&);
 
 bool StartsWith(const std::string& s, const char* prefix) {
-  return s.compare(0, strlen(prefix), prefix) == 0;
+  return strncmp(s.c_str(), prefix, strlen(prefix)) == 0;
 }
 
-bool EndsWith(const std::string& s, const char* suffix) {
+bool StartsWithIgnoreCase(const std::string& s, const char* prefix) {
+  return strncasecmp(s.c_str(), prefix, strlen(prefix)) == 0;
+}
+
+static bool EndsWith(const std::string& s, const char* suffix, bool case_sensitive) {
   size_t suffix_length = strlen(suffix);
   size_t string_length = s.size();
   if (suffix_length > string_length) {
     return false;
   }
   size_t offset = string_length - suffix_length;
-  return s.compare(offset, suffix_length, suffix) == 0;
+  return (case_sensitive ? strncmp : strncasecmp)(s.c_str() + offset, suffix, suffix_length) == 0;
+}
+
+bool EndsWith(const std::string& s, const char* suffix) {
+  return EndsWith(s, suffix, true);
+}
+
+bool EndsWithIgnoreCase(const std::string& s, const char* suffix) {
+  return EndsWith(s, suffix, false);
 }
 
 }  // namespace base
diff --git a/base/strings_test.cpp b/base/strings_test.cpp
index 30ae29e71..5fb21dde6 100644
--- a/base/strings_test.cpp
+++ b/base/strings_test.cpp
@@ -134,44 +134,113 @@ TEST(strings, join_unordered_set) {
               "2,1" == android::base::Join(list, ','));
 }
 
-TEST(strings, startswith_empty) {
+TEST(strings, StartsWith_empty) {
   ASSERT_FALSE(android::base::StartsWith("", "foo"));
   ASSERT_TRUE(android::base::StartsWith("", ""));
 }
 
-TEST(strings, startswith_simple) {
+TEST(strings, StartsWithIgnoreCase_empty) {
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("", "foo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("", ""));
+}
+
+TEST(strings, StartsWith_simple) {
   ASSERT_TRUE(android::base::StartsWith("foo", ""));
   ASSERT_TRUE(android::base::StartsWith("foo", "f"));
   ASSERT_TRUE(android::base::StartsWith("foo", "fo"));
   ASSERT_TRUE(android::base::StartsWith("foo", "foo"));
 }
 
-TEST(strings, startswith_prefix_too_long) {
+TEST(strings, StartsWithIgnoreCase_simple) {
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", ""));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "f"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "F"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "fo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "fO"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "Fo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "FO"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "foo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "foO"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "fOo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "fOO"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "Foo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "FoO"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "FOo"));
+  ASSERT_TRUE(android::base::StartsWithIgnoreCase("foo", "FOO"));
+}
+
+TEST(strings, StartsWith_prefix_too_long) {
   ASSERT_FALSE(android::base::StartsWith("foo", "foobar"));
 }
 
-TEST(strings, startswith_contains_prefix) {
+TEST(strings, StartsWithIgnoreCase_prefix_too_long) {
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foo", "foobar"));
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foo", "FOOBAR"));
+}
+
+TEST(strings, StartsWith_contains_prefix) {
   ASSERT_FALSE(android::base::StartsWith("foobar", "oba"));
   ASSERT_FALSE(android::base::StartsWith("foobar", "bar"));
 }
 
-TEST(strings, endswith_empty) {
+TEST(strings, StartsWithIgnoreCase_contains_prefix) {
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foobar", "oba"));
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foobar", "OBA"));
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foobar", "bar"));
+  ASSERT_FALSE(android::base::StartsWithIgnoreCase("foobar", "BAR"));
+}
+
+TEST(strings, EndsWith_empty) {
   ASSERT_FALSE(android::base::EndsWith("", "foo"));
   ASSERT_TRUE(android::base::EndsWith("", ""));
 }
 
-TEST(strings, endswith_simple) {
+TEST(strings, EndsWithIgnoreCase_empty) {
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("", "foo"));
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("", "FOO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("", ""));
+}
+
+TEST(strings, EndsWith_simple) {
   ASSERT_TRUE(android::base::EndsWith("foo", ""));
   ASSERT_TRUE(android::base::EndsWith("foo", "o"));
   ASSERT_TRUE(android::base::EndsWith("foo", "oo"));
   ASSERT_TRUE(android::base::EndsWith("foo", "foo"));
 }
 
-TEST(strings, endswith_prefix_too_long) {
+TEST(strings, EndsWithIgnoreCase_simple) {
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", ""));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "o"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "O"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "oo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "oO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "Oo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "OO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "foo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "foO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "fOo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "fOO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "Foo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "FoO"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "FOo"));
+  ASSERT_TRUE(android::base::EndsWithIgnoreCase("foo", "FOO"));
+}
+
+TEST(strings, EndsWith_prefix_too_long) {
   ASSERT_FALSE(android::base::EndsWith("foo", "foobar"));
 }
 
-TEST(strings, endswith_contains_prefix) {
+TEST(strings, EndsWithIgnoreCase_prefix_too_long) {
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("foo", "foobar"));
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("foo", "FOOBAR"));
+}
+
+TEST(strings, EndsWith_contains_prefix) {
   ASSERT_FALSE(android::base::EndsWith("foobar", "oba"));
   ASSERT_FALSE(android::base::EndsWith("foobar", "foo"));
 }
+
+TEST(strings, EndsWithIgnoreCase_contains_prefix) {
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("foobar", "OBA"));
+  ASSERT_FALSE(android::base::EndsWithIgnoreCase("foobar", "FOO"));
+}