feat(config): Add directive for file inclusion

include/components/config.hpp

@@ -74,7 +74,7 @@ class config {
   T get(const string& section, const string& key) const {
     auto it = m_sections.find(section);
     if (it == m_sections.end() || it->second.find(key) == it->second.end()) {
-      throw key_error("Missing parameter [" + section + "." + key + "]");
+      throw key_error("Missing parameter \"" + section + "." + key + "\"");
     }
     return dereference<T>(section, key, it->second.at(key), convert<T>(string{it->second.at(key)}));
   }
@@ -125,7 +125,7 @@ class config {
     }
 
     if (results.empty()) {
-      throw key_error("Missing parameter [" + section + "." + key + "-0]");
+      throw key_error("Missing parameter \"" + section + "." + key + "-0\"");
     }
 
     return results;
@@ -220,7 +220,7 @@ class config {
     } else if ((pos = path.find(".")) != string::npos) {
       return dereference_local<T>(path.substr(0, pos), path.substr(pos + 1), section);
     } else {
-      throw value_error("Invalid reference defined at [" + section + "." + key + "]");
+      throw value_error("Invalid reference defined at \"" + section + "." + key + "\"");
     }
   }
 
@@ -251,7 +251,8 @@ class config {
       size_t pos;
       if ((pos = key.find(':')) != string::npos) {
         string fallback = key.substr(pos + 1);
-        m_log.info("The reference ${%s.%s} does not exist, using defined fallback value \"%s\"", section, key.substr(0, pos), fallback);
+        m_log.info("The reference ${%s.%s} does not exist, using defined fallback value \"%s\"", section,
+            key.substr(0, pos), fallback);
         return convert<T>(move(fallback));
       }
       throw value_error("The reference ${" + section + "." + key + "} does not exist (no fallback set)");

include/utils/string.hpp

@@ -77,9 +77,9 @@ namespace string_util {
   string strip(const string& haystack, char needle);
   string strip_trailing_newline(const string& haystack);
 
-  string ltrim(string&& value, const char& needle);
-  string rtrim(string&& value, const char& needle);
-  string trim(string&& value, const char& needle);
+  string ltrim(string&& value, const char& needle = ' ');
+  string rtrim(string&& value, const char& needle = ' ');
+  string trim(string&& value, const char& needle = ' ');
 
   string join(const vector<string>& strs, const string& delim);
   vector<string>& split_into(const string& s, char delim, vector<string>& container);

src/components/config.cpp

@@ -77,21 +77,58 @@ void config::warn_deprecated(const string& section, const string& key, string re
  * Parse key/value pairs from the configuration file
  */
 void config::parse_file() {
-  std::ifstream in(m_file);
-  string line;
-  string section;
-  unsigned int lineno{0};
-
-  while (std::getline(in, line)) {
-    lineno++;
-
-    line = string_util::replace_all(line, "\t", "");
+  vector<pair<int, string>> lines;
+  vector<string> files{m_file};
 
+  std::function<void(int, string&&)> pushline = [&](int lineno, string&& line) {
     // Ignore empty lines and comments
     if (line.empty() || line[0] == ';' || line[0] == '#') {
-      continue;
+      return;
     }
 
+    string key, value;
+    string::size_type pos;
+
+    // Filter lines by:
+    // - key/value pairs
+    // - section headers
+    if ((pos = line.find('=')) != string::npos) {
+      key = forward<string>(string_util::trim(forward<string>(line.substr(0, pos))));
+      value = forward<string>(string_util::trim(line.substr(pos + 1)));
+    } else if (line[0] != '[' || line[line.length() - 1] != ']') {
+      return;
+    }
+
+    if (key == "include-file") {
+      if (value.empty() || !file_util::exists(value)) {
+        throw value_error("Invalid include file \"" + value + "\" defined on line " + to_string(lineno));
+      }
+      if (std::find(files.begin(), files.end(), value) != files.end()) {
+        throw value_error("Recursive include file \"" + value + "\"");
+      }
+      files.push_back(value);
+      m_log.trace("config: Including file \"%s\"", value);
+      for (auto&& l : string_util::split(file_util::contents(value), '\n')) {
+        pushline(lineno, forward<string>(l));
+      }
+      files.pop_back();
+    } else {
+      lines.emplace_back(make_pair(lineno, line));
+    }
+  };
+
+  int lineno{0};
+  string line;
+  std::ifstream in(m_file);
+  while (std::getline(in, line)) {
+    pushline(++lineno, string_util::replace_all(line, "\t", ""));
+  }
+
+  string section;
+  for (auto&& l : lines) {
+    auto& lineno = l.first;
+    auto& line = l.second;
+
     // New section
     if (line[0] == '[' && line[line.length() - 1] == ']') {
       section = line.substr(1, line.length() - 2);
@@ -107,7 +144,7 @@ void config::parse_file() {
       continue;
     }
 
-    string key{forward<string>(string_util::trim(forward<string>(line.substr(0, equal_pos)), ' '))};
+    string key{forward<string>(string_util::trim(forward<string>(line.substr(0, equal_pos))))};
     string value;
 
     auto it = m_sections[section].find(key);
@@ -116,7 +153,7 @@ void config::parse_file() {
     }
 
     if (equal_pos + 1 < line.size()) {
-      value = forward<string>(string_util::trim(line.substr(equal_pos + 1), ' '));
+      value = forward<string>(string_util::trim(line.substr(equal_pos + 1)));
       size_t len{value.size()};
       if (len > 2 && value[0] == '"' && value[len - 1] == '"') {
         value.erase(len - 1, 1).erase(0, 1);
@@ -149,13 +186,14 @@ void config::copy_inherited() {
         // Get name of base section
         auto inherit = param.second;
         if ((inherit = dereference<string>(section.first, param.first, inherit, inherit)).empty()) {
-          throw value_error("[" + section.first + "." + KEY_INHERIT + "] requires a value");
+          throw value_error("Invalid section \"\" defined for \"" + section.first + "." + KEY_INHERIT + "\"");
         }
 
         // Find and validate base section
         auto base_section = m_sections.find(inherit);
         if (base_section == m_sections.end()) {
-          throw value_error("[" + section.first + "." + KEY_INHERIT + "] invalid reference \"" + inherit + "\"");
+          throw value_error(
+              "Invalid section \"" + inherit + "\" defined for \"" + section.first + "." + KEY_INHERIT + "\"");
         }
 
         m_log.trace("config: Copying missing params (sub=\"%s\", base=\"%s\")", section.first, inherit);

src/utils/file.cpp

@@ -190,7 +190,11 @@ namespace file_util {
   string contents(const string& filename) {
     try {
       string contents;
-      std::getline(std::ifstream(filename, std::ifstream::in), contents);
+      string line;
+      std::ifstream in(filename, std::ifstream::in);
+      while (std::getline(in, line)) {
+        contents += line + '\n';
+      }
       return contents;
     } catch (const std::ifstream::failure& e) {
       return "";

tests/unit_tests/utils/string.cpp

@@ -43,6 +43,7 @@ int main() {
   };
 
   "trim"_test = [] {
+    expect(string_util::trim("  x x ") == "x x");
     expect(string_util::ltrim("xxtestxx", 'x') == "testxx");
     expect(string_util::rtrim("xxtestxx", 'x') == "xxtest");
     expect(string_util::trim("xxtestxx", 'x') == "test");