add CombinePaths functions

Author: nickcharron

beam_utils/include/beam_utils/filesystem.h

@@ -48,6 +48,31 @@ bool HasExtension(const std::string& input, const std::string& extension);
  */
 std::string LibbeamRoot();
 
+/**
+ * @brief remove duplicate file separators in a string filepath
+ * 
+ * @param path 
+ * @return std::string 
+ */
+std::string RemoveDuplicateFileSeparators(const std::string& path);
+
+/**
+ * @brief safe way (for all OSs) of combining paths. Uses std::filesystem
+ *
+ * @param path1 first path to add
+ * @param path2 second path to add
+ * @return std::string
+ */
+std::string CombinePaths(const std::string& path1, const std::string& path2);
+
+/**
+ * @brief safe way (for all OSs) of combining paths. Uses std::filesystem
+ *
+ * @param paths vector of paths to combine in order
+ * @return std::string
+ */
+std::string CombinePaths(const std::vector<std::string>& paths);
+
 /**
  * @brief get a vector of absolute paths to files in a directory
  * @param directory absolute path to directory to search in

beam_utils/src/filesystem.cpp

@@ -36,6 +36,42 @@ std::string LibbeamRoot() {
   return root_location;
 }
 
+std::string CleanupPath(const std::string& path) {
+  namespace fs = boost::filesystem;
+  if (path.size() < 3) { return path; }
+  std::string return_path;
+  for (uint32_t i = 0; i < path.size() - 1; i++) {
+    return_path += path[i];
+    if (path[i] == fs::path::preferred_separator &&
+        path[i + 1] == fs::path::preferred_separator) {
+      i++;
+    }
+  }
+
+  // add last character only if not a file separator
+  if (path[path.size() - 1] != fs::path::preferred_separator) {
+    return_path += path[path.size() - 1];
+  }
+  return return_path;
+}
+std::string CombinePaths(const std::string& path1, const std::string& path2) {
+  namespace fs = boost::filesystem;
+  fs::path p1(path1);
+  fs::path p2(path2);
+  fs::path p = p1 / p2;
+  return CleanupPath(p.string());
+}
+
+std::string CombinePaths(const std::vector<std::string>& paths) {
+  namespace fs = boost::filesystem;
+  fs::path p;
+  for (uint32_t i = 0; i < paths.size(); i++) {
+    fs::path p_add(paths[i]);
+    p = p / p_add;
+  }
+  return CleanupPath(p.string());
+}
+
 std::vector<std::string> GetFiles(const std::string& directory,
                                   const std::string& extension,
                                   bool recursive) {

beam_utils/tests/filesystem_test.cpp

@@ -1,5 +1,6 @@
 #include <fstream>
 #include <iostream>
+#include <sys/utsname.h>
 
 #include <boost/filesystem.hpp>
 #include <catch2/catch.hpp>
@@ -99,6 +100,38 @@ TEST_CASE("LibbeamRoot tests", "[filesystem.hpp]") {
   REQUIRE(this_file_true_location == this_file_expected_location);
 }
 
+TEST_CASE("CombinePaths tests", "[filesystem.hpp]") {
+  std::string p_root1 = "/home/nick";
+  std::string p_root2 = "/home/nick/";
+  std::string p_add1 = "/test.cpp";
+  std::string p_add2 = "test.cpp";
+  std::string p_add3 = "test";
+  std::string p_add4 = "/test/";
+
+  struct utsname os_name;
+  uname(&os_name);
+  if (std::string(os_name.sysname) == "Linux") {
+    std::cout << "Linux OS detected, running CombinePaths tests\n";
+    REQUIRE(beam::CombinePaths(p_root1, p_add1) == "/home/nick/test.cpp");
+    REQUIRE(beam::CombinePaths(p_root1, p_add2) == "/home/nick/test.cpp");
+    REQUIRE(beam::CombinePaths(p_root2, p_add1) == "/home/nick/test.cpp");
+    REQUIRE(beam::CombinePaths(p_root2, p_add2) == "/home/nick/test.cpp");
+    REQUIRE(beam::CombinePaths(p_root1, p_add3) == "/home/nick/test");
+    REQUIRE(beam::CombinePaths(p_root1, p_add4) == "/home/nick/test");
+
+    std::string combined1 = beam::CombinePaths(p_root1, p_add4);
+    REQUIRE(beam::CombinePaths(combined1, p_add1) ==
+            "/home/nick/test/test.cpp");
+    REQUIRE(beam::CombinePaths(std::vector<std::string>{
+                p_root1, p_add3, p_add1}) == "/home/nick/test/test.cpp");
+    REQUIRE(beam::CombinePaths(std::vector<std::string>{p_root1, p_add1}) ==
+            "/home/nick/test.cpp");
+  } else {
+    std::cout << "Cannot run CombinePaths tests which only work for Linux\n";
+    REQUIRE(true);
+  }
+}
+
 TEST_CASE("StringToNumericValues", "[filesystem.hpp]") {
   std::string deliminator_1{","};
   std::string deliminator_2{" "};