Add examples directory and enable builds in CI

Created a directory of . In there I have a simple function to add these
source files. It creates and executable and links to the library.

Building of the examples was enabled in CI and then execute them to compare to
the example output for verification they work.

Author: LinuxDevon

.github/workflows/pipeline.yml

@@ -125,7 +125,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-15-large]
+        os: [macos-15-intel]
         cxx:
           - g++
           - clang++
@@ -229,3 +229,14 @@ jobs:
     - name: Run build
       run: cmake --build build
 
+  test-examples:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Make build directory
+      run: cmake -Bbuild -DDBC_BUILD_EXAMPLES=ON -H$GITHUB_WORKSPACE
+
+    - name: Run example tests
+      run: cmake --build build --target test_examples

CMakeLists.txt

@@ -8,6 +8,7 @@ option(DBC_ENABLE_TESTS "Enable Unittests" ON)
 option(DBC_TEST_LOCALE_INDEPENDENCE "Used to deterime if the libary is locale agnostic when it comes to converting floats. You need `de_DE.UTF-8` locale installed for this testing." OFF)
 option(DBC_GENERATE_DOCS "Use doxygen if installed to generated documentation files" OFF)
 option(DBC_GENERATE_SINGLE_HEADER "This will run the generator for the single header file version. Default is OFF since we make a static build. Requires cargo installed." OFF)
+option(DBC_BUILD_EXAMPLES "Build all the examples in the examples folder." OFF)
 # ---------------------- #
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -123,3 +124,5 @@ add_custom_target(clang-tidy-fix
 	clang-tidy -fix-notes -p ${CMAKE_BINARY_DIR}/compile_commands.json ${SOURCE_FILES} ${HEADER_FILES}
 	DEPENDS ${SOURCE_FILES} ${HEADER_FILES}
 )
+
+add_subdirectory(examples)

examples/CMakeLists.txt

@@ -0,0 +1,23 @@
+project(examples)
+    
+set(EXECUTABLE_EXAMPLES "")
+
+function(add_example_executable SOURCE_NAME SOURCE_FILE)
+    add_executable(${SOURCE_NAME} ${SOURCE_FILE})
+    target_link_libraries(${SOURCE_NAME} PRIVATE dbc)
+	target_compile_definitions(${SOURCE_NAME} PRIVATE DBC_FILE_PATH="${CMAKE_CURRENT_SOURCE_DIR}/dbcs")
+
+    set(EXECUTABLE_EXAMPLES "${SOURCE_NAME} ${EXECUTABLE_EXAMPLES} " PARENT_SCOPE)
+endfunction()
+
+if(DBC_BUILD_EXAMPLES)
+    add_example_executable(read_simple_dbc src/example_read_simple_dbc.cpp EXECUTABLE_EXAMPLES)
+
+    string(STRIP ${EXECUTABLE_EXAMPLES} EXECUTABLE_EXAMPLES)
+
+    add_custom_target(test_examples ALL
+                        DEPENDS "${EXECUTABLE_EXAMPLES}"
+						WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+						COMMAND ${PROJECT_SOURCE_DIR}/validate_examples.py
+	)
+endif()

examples/README.md

@@ -0,0 +1,35 @@
+# Examples
+
+You will find all the examples in the `src/` directory.
+Each example shall be prefixed with `example_` and then named
+with the use case then end with `.cpp`.
+
+There are tests to build and validate that all examples are working.
+You can validate output as well. You need to enclose the expected output
+with `=== +++ ===`. The python script will parse out the text between
+and compare the stdout to the text. You are not required to have test
+output. 
+
+## Build and Run Examples
+
+They are turned off by default and enabled via the `DBC_BUILD_EXAMPLES`
+option. 
+
+A quick getting started is:
+
+```shell
+cmake -DDBC_BUILD_EXAMPLES=ON -Bbuild -H.
+cmake --build build --target read_simple_dbc
+./build/examples/read_simple_dbc
+```
+
+## Testing Examples
+
+There is a cmake target to build the examples and run the tests. 
+
+You can do so with:
+
+```shell
+cmake -DDBC_BUILD_EXAMPLES=ON -Bbuild -H.
+cmake --build build --target test_examples
+```

examples/dbcs/HelloWorld.dbc

@@ -0,0 +1,38 @@
+VERSION "1.0.0"
+
+NS_ :
+	BA_
+	BA_DEF_
+	BA_DEF_DEF_
+	BA_DEF_DEF_REL_
+	BA_DEF_REL_
+	BA_DEF_SGTYPE_
+	BA_REL_
+	BA_SGTYPE_
+	BO_TX_BU_
+	BU_BO_REL_
+	BU_EV_REL_
+	BU_SG_REL_
+	CAT_
+	CAT_DEF_
+	CM_
+	ENVVAR_DATA_
+	EV_DATA_
+	FILTER
+	NS_DESC_
+	SGTYPE_
+	SGTYPE_VAL_
+	SG_MUL_VAL_
+	SIGTYPE_VALTYPE_
+	SIG_GROUP_
+	SIG_TYPE_REF_
+	SIG_VALTYPE_
+	VAL_
+	VAL_TABLE_
+
+BS_:
+
+BU_: DBG DRIVER IO MOTOR SENSOR
+
+BO_ 500 IO_DEBUG: 4 IO
+ SG_ IO_DEBUG_test_unsigned : 0|8@1+ (1,0) [0|0] "m/s" DBG

examples/src/example_read_simple_dbc.cpp

@@ -0,0 +1,45 @@
+/*
+    This is the the very basic use case of the library.
+    Here we are just reading a very basic dbc with one message and signal.
+    
+    All we do below is read the basic information of the dbc files
+    such as the nodes, messages, and signals. This library supports
+    the << operator to print out the messages and signals.
+
+    EXAMPLE OUT:
+
+=== +++ ===
+Version: 1.0.0
+Node: DBG
+Node: DRIVER
+Node: IO
+Node: MOTOR
+Node: SENSOR
+Message: {id: 500, name: IO_DEBUG, size: 4, node: IO}
+Signal: {name: IO_DEBUG_test_unsigned, Multiplexed: False, Start bit: 0, Size: 8, Endianness: Little endian, Value Type: Unsigned, Min: 0.000000, Max: 0.000000, Unit: (m/s), receivers: DBG}
+=== +++ ===
+*/
+
+#include <libdbc/dbc.hpp>
+#include <string>
+
+// `DBC_FILE_PATH` is defined in the build system as an absolute path
+static const std::string dbc_file_path = std::string(DBC_FILE_PATH) + "/HelloWorld.dbc";
+
+int main() {
+    Libdbc::DbcParser parser = Libdbc::DbcParser();
+    parser.parse_file(dbc_file_path);
+
+    std::cout << "Version: " << parser.get_version() << std::endl;
+
+    for(auto const& node: parser.get_nodes()) {
+        std::cout << "Node: " << node << std::endl;
+    }
+
+    for(auto const& message: parser.get_messages()) {
+        std::cout << message << std::endl;
+        for(auto const& signal: message.get_signals()) {
+            std::cout << signal << std::endl;
+        }
+    }
+}

examples/validate_examples.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+import pathlib
+import subprocess
+import os
+import unittest
+
+class TestExamples(unittest.TestCase):
+    def setUp(self):
+        filenames = next(os.walk("./src/"), (None, None, []))[2]
+        self.examples = [file for file in filenames if ".cpp" in file]
+        self.assertGreaterEqual(len(self.examples), 1)
+        self.maxDiff = None  # Enable big diffs of text
+
+    def tearDown(self):
+        pass
+
+    def test_hello_world(self):
+        for example in self.examples:
+            contents = pathlib.Path("src/" + example).read_text()
+            example_binary_name = example.split("example_")[1].split(".cpp")[0]
+            test_output = contents.split("=== +++ ===")[1].lstrip()
+            
+            result = subprocess.run("../build/examples/" + example_binary_name, capture_output=True, text=True)
+            with self.subTest(msg='Check example run'):
+                self.assertEqual(result.returncode, 0)
+                self.assertEqual(result.stdout, test_output)
+                self.assertEqual(result.stderr, "")
+
+if __name__ == '__main__':
+    unittest.main()

src/message.cpp

@@ -111,7 +111,7 @@ const std::string& Message::name() const {
 void Message::add_value_description(const std::string& signal_name, const std::vector<Signal::ValueDescription>& value_descriptor) {
 	for (auto& signal : m_signals) {
 		if (signal.name == signal_name) {
-			signal.value_descriptions = value_descriptor;
+		signal.value_descriptions = value_descriptor;
 			return;
 		}
 	}
@@ -120,7 +120,7 @@ void Message::add_value_description(const std::string& signal_name, const std::v
 std::ostream& operator<<(std::ostream& out, const Message& msg) {
 	out << "Message: {id: " << msg.id() << ", ";
 	out << "name: " << msg.m_name << ", ";
-	out << "size: " << msg.m_size << ", ";
+	out << "size: " << std::to_string(msg.m_size) << ", ";
 	out << "node: " << msg.m_node << "}";
 	return out;
 }

src/signal.cpp

@@ -42,13 +42,13 @@ bool Signal::operator<(const Signal& rhs) const {
 }
 
 std::ostream& operator<<(std::ostream& out, const Signal& sig) {
-	out << "Signal {name: " << sig.name << ", ";
+	out << "Signal: {name: " << sig.name << ", ";
 	out << "Multiplexed: " << (sig.is_multiplexed ? "True" : "False") << ", ";
-	out << "Start bit: " << sig.start_bit << ", ";
-	out << "Size: " << sig.size << ", ";
+	out << "Start bit: " << std::to_string(sig.start_bit) << ", ";
+	out << "Size: " << std::to_string(sig.size) << ", ";
 	out << "Endianness: " << (sig.is_bigendian ? "Big endian" : "Little endian") << ", ";
 	out << "Value Type: " << (sig.is_signed ? "Signed" : "Unsigned") << ", ";
-	out << "Min: " << sig.min << ", Max: " << sig.max << ", ";
+	out << "Min: " << std::to_string(sig.min) << ", Max: " << std::to_string(sig.max) << ", ";
 	out << "Unit: (" << sig.unit << "), ";
 	out << "receivers: ";
 	for (const auto& reciever : sig.receivers) {