Move string helpers to utils

src/pngimage.cpp

@@ -18,6 +18,7 @@
 #include "pngimage.hpp"
 #include "tiffimage.hpp"
 #include "types.hpp"
+#include "utils.hpp"
 
 #include <array>
 #include <iostream>
@@ -171,12 +172,6 @@ static bool tEXtToDataBuf(const byte* bytes, long length, DataBuf& result) {
   return true;
 }
 
-std::string upper(const std::string& str) {
-  std::string result;
-  transform(str.begin(), str.end(), std::back_inserter(result), toupper);
-  return result;
-}
-
 std::string::size_type findi(const std::string& str, const std::string& substr) {
   return upper(str).find(upper(substr));
 }

src/utils.cpp

@@ -1,7 +1,24 @@
 #include "utils.hpp"
 
+#include <algorithm>
+#include <cctype>
+#include <iterator>
+
 namespace Exiv2 {
-bool startsWith(const std::string_view& s, const std::string_view& start) {
+bool startsWith(std::string_view s, std::string_view start) {
   return s.find(start) == 0;
 }
+
+std::string upper(const std::string& str) {
+  std::string result;
+  std::transform(str.begin(), str.end(), std::back_inserter(result), ::toupper);
+  return result;
+}
+
+std::string lower(const std::string& a) {
+  std::string b = a;
+  std::transform(a.begin(), a.end(), b.begin(), ::tolower);
+  return b;
+}
+
 }  // namespace Exiv2

src/utils.hpp

@@ -1,10 +1,18 @@
 #ifndef EXIV2_UTILS_HPP
 #define EXIV2_UTILS_HPP
 
+#include <string>
 #include <string_view>
 
 namespace Exiv2 {
-bool startsWith(const std::string_view& s, const std::string_view& start);
-}
+bool startsWith(std::string_view s, std::string_view start);
+
+/// @brief Returns the uppercase version of \b str
+std::string upper(const std::string& str);
+
+/// @brief Returns the lowercase version of \b str
+std::string lower(const std::string& str);
+
+}  // namespace Exiv2
 
 #endif  // EXIV2_UTILS_HPP

src/xmpsidecar.cpp

@@ -7,6 +7,7 @@
 #include "error.hpp"
 #include "futils.hpp"
 #include "image.hpp"
+#include "utils.hpp"
 #include "xmp_exiv2.hpp"
 
 #include <iostream>
@@ -82,16 +83,8 @@ void XmpSidecar::readMetadata() {
   copyXmpToExif(xmpData_, exifData_);
 }  // XmpSidecar::readMetadata
 
-// lower case string
-/// \todo very similar function in pngimage (upper). We should move those things to a string utilities file
-static std::string toLowerCase(const std::string& a) {
-  std::string b = a;
-  std::transform(a.begin(), a.end(), b.begin(), ::tolower);
-  return b;
-}
-
 static bool matchi(const std::string& key, const char* substr) {
-  return toLowerCase(key).find(substr) != std::string::npos;
+  return lower(key).find(substr) != std::string::npos;
 }
 
 void XmpSidecar::writeMetadata() {

unitTests/CMakeLists.txt

@@ -25,6 +25,7 @@ add_executable(unit_tests
     test_tiffheader.cpp
     test_types.cpp
     test_TimeValue.cpp
+    test_utils.cpp
     test_XmpKey.cpp
     $<TARGET_OBJECTS:exiv2lib_int>
 )

unitTests/test_utils.cpp

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "utils.hpp"
+
+#include <gtest/gtest.h>
+
+using namespace Exiv2;
+
+TEST(stringUtils, startsWithReturnsTrue) {
+  ASSERT_TRUE(startsWith("Exiv2 rocks", "Exiv2"));
+}
+
+TEST(stringUtils, startsWithReturnsFlase) {
+  ASSERT_FALSE(startsWith("Exiv2 rocks", "exiv2"));
+}
+
+TEST(stringUtils, upperTransformStringToUpperCase) {
+  ASSERT_EQ("EXIV2 ROCKS", upper("Exiv2 rocks"));
+}
+
+TEST(stringUtils, lowerTransformStringToLowerCase) {
+  ASSERT_EQ("exiv2 rocks", lower("EXIV2 ROCKS"));
+}