Arduino Serial Fixture for unit tests

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This library provides a fixture for the Arduino Serial library to allow for offline unit tests.

Please see ReadTheDocs for the latest documentation.

Introduction

Offline unit testing of Arduino code is challenging because of missing libraries. In this project, we aim to make code using the standard Serial interface testable using the Catch2 unit testing framework.

Installation

In this section we cover retrieval of the latest release or development version of the code.

Prerequisites

This project uses the Catch2 unit testing framework. On Debian based systems, this can be installed via the package manager.

apt install catch

For other distributions and operating systems, see the Catch2 documentation.

Download

Latest release

Navigate to the latest release and either download the .zip or the .tar.gz file.

Unpack the downloaded archive.

From source

The source is hosted on GitHub, to install the latest development version, use the following command.

git clone https://github.com/jfjlaros/arduino-serial-fixture.git

Usage

In this section we describe how to use the Arduino Serial fixture and how to use a number of additional convenience functions. We assume that the library is installed in the directory where the unit tests reside.

Compilation

First compile the fixture.

g++ -c arduino-serial-fixture/src/Arduino.cc

For all tests that require the serial interface, i.e., tests that require Arduino.h, make sure that the path to the fixture is set.

g++ -I arduino-serial-fixture/src -c test_something.cc

Finally, compile the test main code and link.

g++ -o run_tests test_lib.cc test_something.o Arduino.o

Library

The fixture includes most commonly used functions for serial communication. Additionally, some convenience functions are included to make testing easier. These functions can be accessed by including the header.

#include <Arduino.h>

Easy reading and writing

The functions autoRead() and autoWrite() can be used to read or write to the serial device. These functions take care of type encoding automatically. If, for example, we want to read an integer and a float, we use autoRead() as follows.

int i = Serial.autoRead<int>();
float f = Serial.autoRead<float>();

Conversely, easy writing of an integer and a float can be done with autoWrite() as follows.

autoWrite(1234);
autoWrite(3.14F);

Inspecting and preparing data

The functions inspect() and prepare() can be used to inspect the output buffer and to prepare the input buffer. The inspect() function works like the autoRead() function, except that it operates on the output buffer and does not change any of the internal buffer offsets. If for example, the output buffer contains the string xyz, we can use inspect() as follows.

String s = Serial.inspect<String>(); // Yields "xyz".
char c = Serial.inspect<char>(); // Yields 'x'.

The function prepare() is used to prepare the input buffer. It accepts an arbitrary amount of variables that are of either basic types (e.g., int, char, float, etc.) or of type String. If for example, we want to put a char, a string and an integer in the input buffer, we can use prepare() as follows.

Serial.prepare('c', "xyz", 10);

Contributors

• Jeroen F.J. Laros <jlaros@fixedpoint.nl> (Original author, maintainer)

Find out who contributed:

git shortlog -s -e