serial.introduction

metal.serial is an ultra light-weight unit-testing library for gcc, to be used with a serial port or any interface the provides a byte stream. It's purpose is to allow fast and simple unit-testing on embedded systems that do not provide debugger access.

• two test levels (assertion/expecation)
• log messages
• test cases
• human-readable-format or json output
• success indication through the exit-code
• C and C++ implementation

Here's a simple example of a test with metal.serial:

#include <metal/serial.hpp>
#include <cstdio>

int main(int argc, char *argv[])
{
    int i = 41;
    i++;
    
    METAL_SERIAL_INIT();
    METAL_SERIAL_ASSERT_EQUAL(i, 42);
    METAL_SERIAL_TEST_EXIT(); //report the result
    return 0;
}

void write_metal_serial(char c) {std::putchar(c); }//implementation of the byte stream

Using the metal.serial we execute the file (test) and pipe the output into metal.serial to validate them.

test | metal.serial test 

This will generate a detailed report and cause metal.serial to yield the exit_code expected from test. It is of course much more likely that data will be received from a serial port (or any other interface) which can be achieved by reading directly from the hardware:

metal.serial test.elf < /dev/ttyUSB0

This works by outputting the location in the binary, using addr2line to find the code-location and parse the line from the code.