Testing Embedded Systems With Cucumber

Ian Dees • @undeesCukeUp! NYC 2013

Plenty of Ruby, but...

There will be C

There will be C++

There will be C#

http://pragprog.com/titles/dhwcr

discount code:CucumberIanDees

The Embedded Continuum

almost acomputer

chip andsome ROM

Simple devicesNo Ruby, no Cucumber

Gray CodeA simple system to test

Feature: Gray Code Scenario Outline: Counter When I press the button Then the LEDs should read "<leds>"

Examples: | leds | | ..O | | .OO | | .O. | | OO. | | OOO | | O.O | | O.. | | ... |

Arduino

void loop() { button.update(); bool buttonPressed = button.risingEdge();

if (buttonPressed) { counter = (counter + 1) % ENTRIES; updateLeds(); }

delay(50);}

Drive code directly

void loop() { button.update(); bool buttonPressed = button.risingEdge();

if (buttonPressed) { counter = (counter + 1) % ENTRIES; updateLeds(); }

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

if (buttonPressed) { counter = (counter + 1) % ENTRIES; updateLeds(); }

delay(50);}

static bool isFakeButtonPressed;

class Bounce {public: // ...

bool risingEdge() { bool result = isFakeButtonPressed; isFakeButtonPressed = false; return result; }};

extern "C" void press() { isFakeButtonPressed = true;}

const char* leds() { static char buf[LEDS + 1] = {0};

for (int i = 0; i < LEDS; ++i) { buf[i] = STATES[counter][i] == HIGH ? 'O' : '.'; }

return buf;}

https://github.com/ffi/ffi

FFI

require 'ffi'

module Arduino extend FFI::Library ffi_lib 'graycode'

attach_function :press, [], :void attach_function :leds, [], :string

attach_function :setup, [], :void attach_function :loop, [], :voidend

When /^I press the button$/ do Arduino.press Arduino.loopend

Then /^the LEDs should read "(.*?)"$/ do |leds|

expect(Arduino.leds).to eq(leds)end

Cucumber Wire Protocol

Cucumber-CPPhttps://github.com/cucumber/cucumber-cpp

host: localhostport: 3902

features/step_definitions/cucumber.wire

When /^I press the button$/ do Arduino.press Arduino.loopend

Then /^the LEDs should read "(.*?)"$/ do |expected| expect(Arduino.leds).to eq(expected)end

WHEN("^I press the button$") { press(); loop();}

THEN("^the LEDs should read \"(.*?)\"$") { REGEX_PARAM(string, expected); BOOST_CHECK_EQUAL(leds(), expected);}

Bespoke wire server

http://www.2600.com/code/212/listener.c

listen/accept/read/write

while(fgets(buf,sizeof buf,rStream)) { respond_to_cucumber(wStream, buf);}

step_matchesinvoke

Two messages

Then the LEDs should read "..O"

⬇["step_matches", {"name_to_match": "the LEDs should read"}]

⬇["success", [{"id":"1", "args":[{"val":"..O", "pos":"22"}]}]]

json spirithttp://www.codeproject.com/KB/recipes/

JSON_Spirit.aspx

extern "C" void respond_to_cucumber( FILE* stream, const char* message) { string s = message; Value v; read(s, v);

Array& a = v.get_array(); string type = a[0].get_str();

// handle Cucumber message types

report_success(stream);}

if (type == "step_matches") { string name = step_name(v);

if (name == "I press the button") { report_success(stream); return; } else if (...)

// ...

}}

if (type == "step_matches") { string name = step_name(v);

if (name == "I press the button") { report_success(stream); return; } else if (...)

// ...

}}

if (type == "step_matches") { string name = step_name(v);

if (...) { // ...

} else if (name.find("the LEDs") == 0) const int START = 22; string leds = name.substr(START, 3); report_match(leds, START, stream); return; }}

Then the LEDs should read "..O"

⬇["invoke", {"id":"1", "args":["..O"]}]

⬇["success", []]

if (type == "invoke") { string id = step_id(v);

if (id == "0") { press(); loop(); } else if (id == "1") {

// ...

} } }

if (type == "invoke") { string id = step_id(v);

if (id == "0") { press(); loop(); } else if (id == "1") {

// ...

} } }

if (type == "invoke") { string id = step_id(v);

if (id == "0") { // ...

} else if (id == "1") { string expected = step_leds(v); if (expected != leds()) { report_failure("LEDs", stream); return; } } }

https://github.com/hparra/ruby-serialport

Serial

void loop() { button.update(); bool buttonPressed = button.risingEdge();

if (buttonPressed) { counter = (counter + 1) % ENTRIES; updateLeds(); }

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

if ( buttonPressed ) { counter = (counter + 1) % ENTRIES; updateLeds();

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

int command = (Serial.available() > 0 ? Serial.read() : -1);

if (isIncrement(buttonPressed, command)) { counter = (counter + 1) % ENTRIES; updateLeds(); } else if (isQuery(command)) { Serial.write(leds()); Serial.write('\n'); }

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

int command = (Serial.available() > 0 ? Serial.read() : -1);

if (isIncrement(buttonPressed, command)) { counter = (counter + 1) % ENTRIES; updateLeds(); } else if (isQuery(command)) { Serial.write(leds()); Serial.write('\n'); }

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

int command = (Serial.available() > 0 ? Serial.read() : -1);

if (isIncrement(buttonPressed, command)) { counter = (counter + 1) % ENTRIES; updateLeds(); } else if (isQuery(command)) { Serial.write(leds()); Serial.write('\n'); }

delay(50);}

void loop() { button.update(); bool buttonPressed = button.risingEdge();

int command = (Serial.available() > 0 ? Serial.read() : -1);

if (isIncrement(buttonPressed, command)) { counter = (counter + 1) % ENTRIES; updateLeds(); } else if (isQuery(command)) { Serial.write(leds()); Serial.write('\n'); }

delay(50);}

require 'serialport'

module Arduino @@port = SerialPort.open 2, 9600 at_exit { @@port.close }

def self.press @@port.write '+' end

def self.leds @@port.write '?' @@port.read.strip endend

Ruby, C#, SpecFlow, Cucumber

Almost a computer

Feature: Calculator

Scenario: Add two numbers When I multiply 2 and 3 Then I should get 6

Run Cucumber directly

rsync -av --delete . remote1:test_path

ssh remote1 'cd test_path && cucumber'

Drive the GUI

TestStack Whitehttps://github.com/TestStack/White

namespace Calc.Spec{ [Binding] public class CalculatorSteps { private Window window;

[Before] public void Before() { Application application = Application.Launch("calc.exe"); window = application.GetWindow( "Calculator", InitializeOption.NoCache); } // ... }}

namespace Calc.Spec{ [Binding] public class CalculatorSteps { private Window window;

[Before] public void Before() { Application application = Application.Launch("calc.exe"); window = application.GetWindow( "Calculator", InitializeOption.NoCache); } // ... }}

namespace Calc.Spec{ [Binding] public class CalculatorSteps { private Window window;

[Before] public void Before() { Application application = Application.Launch("calc.exe"); window = application.GetWindow( "Calculator", InitializeOption.NoCache); } // ... }}

[When(@"I multiply (.*) and (.*)")]public void WhenIMultiply(string a, string b){ window.Keyboard.Enter(a + "*" + b + "=");}

[Then(@"I should get (.*)")]public void ThenIShouldGet(string expected){ window.Get<Label>(expected);}

Give your app an API

Mongoose web server

int main(){ struct mg_context *ctx = mg_start(); mg_set_option(ctx, "ports", "33333");

mg_set_uri_callback(ctx, "/", &show_index, 0); mg_set_uri_callback(ctx, "/multiply", &multiply, 0); mg_set_uri_callback(ctx, "/result", &get_result, 0);

getchar(); mg_stop(ctx);

return 0;}

int main(){ struct mg_context *ctx = mg_start(); mg_set_option(ctx, "ports", "33333");

mg_set_uri_callback(ctx, "/", &show_index, 0); mg_set_uri_callback(ctx, "/multiply", &multiply, 0); mg_set_uri_callback(ctx, "/result", &get_result, 0);

getchar(); mg_stop(ctx);

return 0;}

static void multiply( struct mg_connection *conn, const struct mg_request_info *request_info, void *user_data){ char *ap = mg_get_var(conn, "multiplier"); char *bp = mg_get_var(conn, "multiplicand");

int a = atol(ap); int b = atol(bp);

result = a * b;

mg_printf(conn, "HTTP/1.1 200 OK\r\n\Content-Type: text/plain\r\n\r\n");

mg_free(multiplier_s); mg_free(multiplicand_s);}

static void multiply( struct mg_connection *conn, const struct mg_request_info *request_info, void *user_data){ char *ap = mg_get_var(conn, "multiplier"); char *bp = mg_get_var(conn, "multiplicand");

int a = atol(ap); int b = atol(bp);

result = a * b;

mg_printf(conn, "HTTP/1.1 200 OK\r\n\Content-Type: text/plain\r\n\r\n");

mg_free(multiplier_s); mg_free(multiplicand_s);}

static void multiply( struct mg_connection *conn, const struct mg_request_info *request_info, void *user_data){ char *ap = mg_get_var(conn, "multiplier"); char *bp = mg_get_var(conn, "multiplicand");

int a = atol(ap); int b = atol(bp);

result = a * b;

mg_printf(conn, "HTTP/1.1 200 OK\r\n\Content-Type: text/plain\r\n\r\n");

mg_free(multiplier_s); mg_free(multiplicand_s);}

static void multiply( struct mg_connection *conn, const struct mg_request_info *request_info, void *user_data){ char *ap = mg_get_var(conn, "multiplier"); char *bp = mg_get_var(conn, "multiplicand");

int a = atol(ap); int b = atol(bp);

result = a * b;

mg_printf(conn, "HTTP/1.1 200 OK\r\n\Content-Type: text/plain\r\n\r\n");

mg_free(multiplier_s); mg_free(multiplicand_s);}

static void get_result( struct mg_connection *conn, const struct mg_request_info *request_info, void *user_data){ mg_printf(conn, "HTTP/1.1 200 OK\r\n\Content-Type: text/plain\r\n\r\n%d", result);}

https://github.com/jnunemaker/httparty

HTTParty

When(/^I multiply (\d+) and (\d+)$/) do |a, b| Calculator.multiply a, bend

Then(/^I should get (\d+)$/) do |n| expect(Calculator.result).to eq(n.to_i)end

require 'httparty'

class Calculator include HTTParty base_uri 'localhost:33333'

def self.multiply(a, b) get "/multiply?multiplier=#{a}\&multiplicand=#{b}" end

def self.result get("/result").to_i endend

(because tl;dr is passé)

In summary:

Have source? Device Technique

yes simple Direct

yes simple Serial

yes mediumCucumber Wire

Protocol

yes powerful Custom TCP

no powerful GUI

Thank youhttps://github.com/undees/cukeup