Closes #3 Validate DBC frame definitions and report error locations

tests/README.md

@@ -26,3 +26,22 @@ signals, signed values, scaling, 64-bit extraction, signed/unsigned boundary val
 (including `INT64_MIN`, `INT64_MAX`, and `UINT64_MAX`), numeric output, invalid lengths, insufficient
 payloads, and Intel regression cases. Frame validity means the definition was
 found; insufficient payloads are checked through signal validity.
+
+## Parser regression tests
+
+Run from the repository root:
+
+```sh
+g++ -std=c++17 -Wall -Wextra -Wpedantic -Werror -I. \
+  tests/dbc_parser_test.cpp dbc_parser.cpp -o /tmp/dbc_parser_test
+/tmp/dbc_parser_test
+```
+
+For qmake, use `tests/dbc_parser_test.pro` in a separate build directory,
+following the decoder instructions above, then run `./dbc_parser_test`.
+
+Parser tests cover standard and extended CAN IDs, whitespace, payload storage
+boundaries, missing fields, malformed and overflowing numbers, reserved ID bits,
+error paths and line numbers, and integration with signals and comments.
+Temporary DBC fixtures are created in the system temporary directory and removed
+automatically.

tests/dbc_parser_test.cpp

@@ -0,0 +1,94 @@
+#include "dbc_parser.h"
+
+#include <chrono>
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <stdexcept>
+
+struct Fixture {
+  std::filesystem::path path = std::filesystem::temp_directory_path() /
+    ("dbc_parser_test_" + std::to_string (
+      std::chrono::steady_clock::now().time_since_epoch().count()) + ".dbc");
+  ~Fixture() { std::error_code error; std::filesystem::remove (path, error); }
+  void Write (const std::string &text) const {
+    std::ofstream output (path);
+    output << text;
+    if (!output)
+      throw std::runtime_error ("Cannot write test fixture.");
+  }
+};
+
+int main() {
+  Fixture fixture;
+  int failures = 0;
+  std::size_t count = 0U;
+  const auto check = [&] (bool passed, const std::string &name) {
+    ++count;
+    if (!passed) { ++failures; std::cerr << "FAIL: " << name << '\n'; }
+  };
+  struct ValidCase { const char *line; std::uint32_t id; bool extended; unsigned length; };
+  const ValidCase valid[] = {
+    {"BO_ 0 Frame: 0 ECU", 0U, false, 0U},
+    {"BO_ 2047 Frame: 8 ECU", 2047U, false, 8U},
+    {"BO_ 2048 Frame: 64 ECU", 2048U, true, 64U},
+    {"BO_ 536870911 Frame: 255 ECU", 0x1FFFFFFFU, true, 255U},
+    {"BO_ 2147483649 Frame: 8 ECU", 1U, true, 8U},
+    {"BO_ 2684354559 Frame: 8 ECU", 0x1FFFFFFFU, true, 8U},
+    {"  BO_\t256\tFrame :\t8\tECU  \r", 256U, false, 8U}
+  };
+  for (const auto &test : valid) {
+    fixture.Write (std::string (test.line) + '\n');
+    try {
+      const auto database = DbcParser().ParseFile (fixture.path.string());
+      check (database.frames.size() == 1U && database.frames[0].name == "Frame" &&
+             database.frames[0].canId == test.id &&
+             database.frames[0].isExtended == test.extended &&
+             database.frames[0].dlc == test.length &&
+             database.frames[0].transmitter == "ECU", test.line);
+    } catch (const std::exception &error) { check (false, error.what()); }
+  }
+  const char *invalid[] = {
+    "BO_ invalid", "BO_", "BO_ 1", "BO_ 1 : 8 ECU", "BO_ 1 Frame 8 ECU",
+    "BO_ 1 Frame:", "BO_ 1 Frame: 8", "BO_ 1 Frame: 8 ECU extra",
+    "BO_ 1 Two Names: 8 ECU", "BO_ -1 Frame: 8 ECU", "BO_ +1 Frame: 8 ECU",
+    "BO_ 1x Frame: 8 ECU", "BO_ 0x123 Frame: 8 ECU", "BO_ 1.5 Frame: 8 ECU",
+    "BO_ 4294967296 Frame: 8 ECU", "BO_ 999999999999999999999 Frame: 8 ECU",
+    "BO_ 536870912 Frame: 8 ECU", "BO_ 1073741824 Frame: 8 ECU",
+    "BO_ 2684354560 Frame: 8 ECU", "BO_ 4294967295 Frame: 8 ECU",
+    "BO_ 1 Frame: -1 ECU", "BO_ 1 Frame: +8 ECU", "BO_ 1 Frame: 8x ECU",
+    "BO_ 1 Frame: 8.5 ECU", "BO_ 1 Frame: 256 ECU",
+    "BO_ 1 Frame: 4294967296 ECU", "BO_\tinvalid"
+  };
+  for (const auto *line : invalid) {
+    fixture.Write (std::string ("VERSION \"test\"\n\n") + line + '\n');
+    try {
+      DbcParser().ParseFile (fixture.path.string());
+      check (false, line);
+    } catch (const std::runtime_error &error) {
+      const std::string prefix = fixture.path.string() + ":3: ";
+      check (std::string (error.what()).find (prefix) == 0U &&
+             std::string (error.what()).size() > prefix.size(), line);
+    }
+  }
+  fixture.Write (
+    "BO_TX_BU_ 256 : ECU;\nBO_ 256 Frame: 8 ECU\n"
+    " SG_ Speed : 0|16@1+ (0.5,1) [0|100] \"rpm\" ECU\n"
+    "CM_ BO_ 256 \"Frame comment\";\nCM_ SG_ 256 Speed \"Signal comment\";\n"
+    "BO_ 257 Second: 8 ECU\n");
+  const auto database = DbcParser().ParseFile (fixture.path.string());
+  check (database.frames.size() == 2U && database.frames[0].signals.size() == 1U &&
+         database.frames[0].comment == "Frame comment" &&
+         database.frames[0].signals[0].comment == "Signal comment", "Integration");
+  fixture.Write ("\nSG_ Speed : invalid\n");
+  try {
+    DbcParser().ParseFile (fixture.path.string());
+    check (false, "Signal error location");
+  } catch (const std::runtime_error &error) {
+    check (std::string (error.what()).find (fixture.path.string() + ":2: ") == 0U,
+           "Signal error location");
+  }
+  if (failures != 0) return 1;
+  std::cout << "All " << count << " parser cases passed.\n";
+  return 0;
+}

tests/dbc_parser_test.pro

@@ -0,0 +1,7 @@
+TEMPLATE = app
+TARGET = dbc_parser_test
+CONFIG += console c++17
+CONFIG -= app_bundle qt
+INCLUDEPATH += ..
+SOURCES += dbc_parser_test.cpp ../dbc_parser.cpp
+HEADERS += ../dbc_parser.h ../dbc_database.h ../frame_info.h ../signal_info.h