The document discusses property-based testing and provides examples of property tests in different programming languages like Java, PHP, Go, and Rust. It explains the concept of property-based testing where tests make statements about the output of code based on different inputs. Examples include testing properties of a rectangle area function, offer calculations, mean/variance/standard deviation calculations, and quickcheck tests.
Se guardiamo oltre la meccanica, il TDD è una tecnica complessa perché richiede molteplici skill. Da principiante dopo l’implementazione di poche storie ti imbatti nel problema dei test che si rompono ad ogni refactoring, è arrivato il momento di migliorare i propri skill di scrittura dei test. Nel talk analizzeremo la struttura dei test, quali sono le bad smell più comuni e come porvi rimedio.
Se guardiamo oltre la meccanica, il TDD è una tecnica complessa perché richiede molteplici skill. Da principiante dopo l’implementazione di poche storie ti imbatti nel problema dei test che si rompono ad ogni refactoring, è arrivato il momento di migliorare i propri skill di scrittura dei test. Nel talk analizzeremo la struttura dei test, quali sono le bad smell più comuni e come porvi rimedio.
Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/254wkpw.
Aaron Bedra focuses on describing a system as a series of models that can be used to systematically and automatically generate input data and ensure that a code is behaving as expected. Bedra discusses property based testing and how it can help one build more resilient systems and even reduce the time needed to maintain a test suite. Filmed at qconlondon.com.
Aaron Bedra is Chief Security Officer at eligible.com. He is the creator of Repsheet, an open source threat intelligence framework. Bedra is the co-author of Programming Clojure, 2nd Edition and a frequent contributor to open source software.
I am Josh U. I am a Python Homework Expert at pythonhomeworkhelp.com. I hold a Master's in Computer Science from, St. Edward’s University, USA. I have been helping students with their homework for the past 10 years. I solve homework related to Python.
Visit pythonhomeworkhelp.com or email support@pythonhomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with Python Homework.
I am Wycliffe S. I am a Python Homework Expert at pythonhomeworkhelp.com. I hold a Master's in Computer Science from, the University of Aberdeen, UK. I have been helping students with their homework for the past 13 years. I solve homework related to Python.
Visit pythonhomeworkhelp.com or email support@pythonhomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with Python Homework.
Clean Coders Hate What Happens To Your Code When You Use These Enterprise Pro...Kevlin Henney
Presented at ACCU (24th April 2015)
It is all to easy to dismiss problematic codebases on some nebulous idea of bad practice or bad programmers. Poor code, however, is rarely arbitrary and random in its structure or formulation. Systems of code, well or poorly structured, emerge from systems of practice, whether effective or ineffective. To improve code quality, it makes more sense to pick apart the specific practices and see their interplay — the cause — than to simply focus on the code itself — the effect. This talk looks at how a handful of coding habits, design practices and assumptions can systematically balloon code and compound its accidental complexity.
Presented at Agile Prague (16th September 2014)
Video available at https://vimeo.com/108007508
These days testing is considered a sexy topic for programmers. Who'd have thought it? But what makes for good unit tests (GUTs)? There's more to effective unit testing than just knowing the assertion syntax of a framework.
Testing represents a form of communication and, as such, it offers multiple levels and forms of feedback, not just basic defect detection. Effective unit testing requires an understanding of what forms of feedback and communication are offered by tests, and what styles encourage or discourage such qualities.
What style of test partitioning is most common, and yet scales poorly and is ineffective at properly expressing the behaviour of a class or component? What styles, tricks and tips can be used to make tests more specification-like and can scale as the codebase grows?
What We Talk About When We Talk About Unit TestingKevlin Henney
Presented at ACCU (23rd April 2015)
These days unit testing is considered sexy for programmers. Who'd have thought it? But there is a lot more to effective programmer testing than the fashionable donning of a unit-testing framework: writing Good Unit Tests (GUTs) involves (a lot) more than knowledge of assertion syntax.
Testing represents a form of communication and, as such, it offers multiple levels and forms of feedback, not just basic defect detection. Effective unit testing requires an understanding of what forms of feedback and communication are offered by tests, and what styles encourage or discourage such qualities.
What styles of test partitioning are common, and yet scale poorly, are uncohesive and are ineffective at properly expressing the behaviour of a class or component? What styles, tricks and tips can be used to make tests more specification-like and scalable to large codebases? How do we choose between scenario-based and property-based test cases?
Wiktor Toporek: Pomimo tego że JavaScript mocno ewoluował na przestrzeni ostatnich lat, zakorzeniona w nim jego asynchroniczna natura wciąż może sprawiać problem programistom i to zarówno początkującym jak i tym zaawansowanym. W prezentacji przyjrzymy się jednemu z bohaterów programowania asynchronicznego jakim jest Promise, przeanalizujemy niektóre z pułapek oraz zastanowimy się również czy w pełni wykorzystujemy jego potencjał.
Making property-based testing easier to read for humansLaura M. Castro
Agile practices have taught us that both stakeholder involvement and early testing are key to quality software. However, it is usually the case that tools for good communication are not that good for testing, and vice-versa.
In this talk, readSpec (one of the results of the PF7 EU PROWESS project) is presented, a tool that attempts to fill in this gap.
Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/254wkpw.
Aaron Bedra focuses on describing a system as a series of models that can be used to systematically and automatically generate input data and ensure that a code is behaving as expected. Bedra discusses property based testing and how it can help one build more resilient systems and even reduce the time needed to maintain a test suite. Filmed at qconlondon.com.
Aaron Bedra is Chief Security Officer at eligible.com. He is the creator of Repsheet, an open source threat intelligence framework. Bedra is the co-author of Programming Clojure, 2nd Edition and a frequent contributor to open source software.
I am Josh U. I am a Python Homework Expert at pythonhomeworkhelp.com. I hold a Master's in Computer Science from, St. Edward’s University, USA. I have been helping students with their homework for the past 10 years. I solve homework related to Python.
Visit pythonhomeworkhelp.com or email support@pythonhomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with Python Homework.
I am Wycliffe S. I am a Python Homework Expert at pythonhomeworkhelp.com. I hold a Master's in Computer Science from, the University of Aberdeen, UK. I have been helping students with their homework for the past 13 years. I solve homework related to Python.
Visit pythonhomeworkhelp.com or email support@pythonhomeworkhelp.com. You can also call on +1 678 648 4277 for any assistance with Python Homework.
Clean Coders Hate What Happens To Your Code When You Use These Enterprise Pro...Kevlin Henney
Presented at ACCU (24th April 2015)
It is all to easy to dismiss problematic codebases on some nebulous idea of bad practice or bad programmers. Poor code, however, is rarely arbitrary and random in its structure or formulation. Systems of code, well or poorly structured, emerge from systems of practice, whether effective or ineffective. To improve code quality, it makes more sense to pick apart the specific practices and see their interplay — the cause — than to simply focus on the code itself — the effect. This talk looks at how a handful of coding habits, design practices and assumptions can systematically balloon code and compound its accidental complexity.
Presented at Agile Prague (16th September 2014)
Video available at https://vimeo.com/108007508
These days testing is considered a sexy topic for programmers. Who'd have thought it? But what makes for good unit tests (GUTs)? There's more to effective unit testing than just knowing the assertion syntax of a framework.
Testing represents a form of communication and, as such, it offers multiple levels and forms of feedback, not just basic defect detection. Effective unit testing requires an understanding of what forms of feedback and communication are offered by tests, and what styles encourage or discourage such qualities.
What style of test partitioning is most common, and yet scales poorly and is ineffective at properly expressing the behaviour of a class or component? What styles, tricks and tips can be used to make tests more specification-like and can scale as the codebase grows?
What We Talk About When We Talk About Unit TestingKevlin Henney
Presented at ACCU (23rd April 2015)
These days unit testing is considered sexy for programmers. Who'd have thought it? But there is a lot more to effective programmer testing than the fashionable donning of a unit-testing framework: writing Good Unit Tests (GUTs) involves (a lot) more than knowledge of assertion syntax.
Testing represents a form of communication and, as such, it offers multiple levels and forms of feedback, not just basic defect detection. Effective unit testing requires an understanding of what forms of feedback and communication are offered by tests, and what styles encourage or discourage such qualities.
What styles of test partitioning are common, and yet scale poorly, are uncohesive and are ineffective at properly expressing the behaviour of a class or component? What styles, tricks and tips can be used to make tests more specification-like and scalable to large codebases? How do we choose between scenario-based and property-based test cases?
Wiktor Toporek: Pomimo tego że JavaScript mocno ewoluował na przestrzeni ostatnich lat, zakorzeniona w nim jego asynchroniczna natura wciąż może sprawiać problem programistom i to zarówno początkującym jak i tym zaawansowanym. W prezentacji przyjrzymy się jednemu z bohaterów programowania asynchronicznego jakim jest Promise, przeanalizujemy niektóre z pułapek oraz zastanowimy się również czy w pełni wykorzystujemy jego potencjał.
Making property-based testing easier to read for humansLaura M. Castro
Agile practices have taught us that both stakeholder involvement and early testing are key to quality software. However, it is usually the case that tools for good communication are not that good for testing, and vice-versa.
In this talk, readSpec (one of the results of the PF7 EU PROWESS project) is presented, a tool that attempts to fill in this gap.
Better Tests, Less Code: Property-based TestingC4Media
Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/2ms4qCS.
Matt Bachmann presents a few patterns meant to inspire developers to get started with Property-based Testing. Filmed at qconsf.com.
Matt Bachmann works as a Software Engineer in the Commerce team at Fitbit Matt. The Commerce team helps maintain the order pipeline from cart to post purchase support. Prior to his work at Fitbit he worked on content analysis platforms for the identification of PII, PCI, and other potentially sensitive information.
Video and more content at fsharpforfunandprofit.com/pbt
"The lazy programmer's guide to writing 1000's of tests: An introduction to property based testing"
We are all familiar with example-based testing, as typified by TDD and BDD. Property-based testing takes a very different approach, where a single test is run hundreds of times with randomly generated inputs.
Property-based testing is a great way to find edge cases, and also helps you to understand and document the behaviour of your code under all conditions.
This talk will introduce property-based testing and show how it works, and why you should consider adding it to your arsenal of testing tools.
JUnit is the de facto standard in Java testing. Yet many advanced JUnit features are little known and poorly understood. This session reviews some lesser-known features of JUnit, along with a few associated libraries, that can make your unit tests more powerful, expressive, and fun. The session is intended for Java developers, lead developers, and architects trying to introduce good testing practices into their teams.
Visual Programming Lectures using Visual Studio 2015 C# Windows Form Application
Lecturer: Saman M. Almufti / Kurdistan Region, Nawroz University
facebook: https://www.facebook.com/saman.malmufti
Visual Programming using C#
Lecturer: Saman M. Almufti / Kurdistan Region, Nawroz University, (Visitor : Ararat Institute)
facebook: https://www.facebook.com/saman.malmufti
YouTube Link: https://youtu.be/ik_kxvSGwEs
IN THIS LECTURE:
1- for loop
2-while
3-do wile
The secret unit testing tools no one ever told you aboutDror Helper
There are more to unit testing than using a unit testing framework - in order to succeed you want to use the right tools for the job. There are a few tools that almost no one talks about - some enabling creating of top-notch, robust unit tests. Some will help you run your tests better and faster. In this session I'll explain about the inevitable maintainability problems developers face when writing and maintaining huge unit testing suits and how unit level BDD, AutoMocking, and Continuous Execution can help take control over your tests.
This presentation explains parameterized tests, theory tests, and generative testing. It also explains single mode faults and double mode faults and shows how to reduce the number of test cases when there's an combinatorial explosion. Lot's of JUnit examples.
This is a Java Code- you are only creating unit test for Validate and.pdfaamousnowov
This is a Java Code, you are only creating unit test for Validate and ConvertToBinary methods.
Please create at least 2 test for each method and check to see if they are successful. I have
inserted some example unit test as well.
CONVERT SERVICE CLASS:
public class ConvertService {
private Boolean isValid;
private long intValue;
private String hexValue;
private String binaryValue;
public ConvertService(String binaryValue) {
this.binaryValue = binaryValue;
Validate(binaryValue);
if (this.isValid) {
ConvertToInt(binaryValue);
ConvertToHex(binaryValue);
}
}
public ConvertService(long intValue) {
this.intValue = intValue;
Validate(intValue);
if (this.isValid) {
ConvertToBinary(intValue);
ConvertToHex(this.binaryValue);
}
}
public boolean IsValid() {
return isValid;
}
public String BinaryValue() {
return binaryValue;
}
public long IntegerValue() {
return intValue;
}
public String HexadecimalValue() {
return hexValue;
}
/*
* Used when the ConvertService(String binaryValue) constructor is used.
* Validate that the input value is not blank, and less than 32 characters long.
* Validate that the input value is only 1s and 0s.
*/
private void Validate (String value) {
Boolean isValid = true;
if (!is1sAnd0sOnly(value)) {
isValid = false;
}
if (!isProperLength(value)) {
isValid = false;
}
this.isValid = isValid;
}
/*
* Used when the ConvertService(long intvalue) constructor is used.
* Validate that the input value positive and less than 4294967295L
* Note: 4294967295L = FFFFFFFF
*/
//we have to test this
private void Validate (long value) {
Boolean isValid = true;
if (value < 0 || value > 4294967295L)
isValid = false;
this.isValid = isValid;
}
private boolean is1sAnd0sOnly (String str) {
if (str.matches("^[01]+$")) {
return true;
}
return false;
}
private boolean isNullEmptyBlank(String str){
if (str == null || str.equals("") || str.trim().equals(""))
return true;
return false;
}
private boolean isProperLength (String str) {
if (isNullEmptyBlank(str) ||
str.length() <= 32 ) {
return true;
}
return false;
}
private void ConvertToInt(String value) {
long iValue = 0L;
for (int i=0; i<value.length(); i++) {
long multiplier = (long)Math.pow(2, value.length() - 1 - i);
if (value.charAt(i) == '1') {
iValue += multiplier;
}
}
this.intValue = iValue;
}
private void ConvertToHex(String value) {
String hexValue = "";
//Fill the left size of the value with 0's so the length is a multiple of four.
int leftover = value.length() % 4;
if (leftover != 0) {
for (int i=0; i< (4-leftover); i++) {
value = "0" + value;
}
}
for (int i=0; i < value.length() / 4; i++) {
//a nibble is 4 bits
String nibble = value.substring(i*4, (i*4)+4);
if (nibble.equals("0000")) {
hexValue = hexValue + "0";
} else if (nibble.equals("0001")) {
hexValue = hexValue + "1";
} else if (nibble.equals("0010")) {
hexValue = hexValue + "2";
} else if (nibble.equals("0011")) {
hexValue = hexValue + "3";
} else if (nibble.equals("0100")) {
hexValue = hexValue + "4";
} else if (nibble.equals("0101")) {
hexVa.
2. What is property Based Testing?
Property-based tests make statements about the
output of your code based on the input, and these
statements are verified for many different possible
inputs.
3. Example
Let’s think of some properties for the rectangle area function:
1. Given any two width and height values, the result is always a multiple
of the two
2. Order doesn’t matter. A rectangle which is 50×100 has the same area
as one which is 100×50
3. If we divide the area by width, we should get the height
4. public int findArea(int width, int height){
return width*height;
}
public boolean verifyArea(int height, int width,int area){
return (area==height*width)?true:false;
}
public boolean verifyHeight(int area, int widht, int height){
return(height==area/widht)?true:false;
}
public static void main(String[] args) {
for(int i=0;i<100;i++){
int height=(int) (Math.random()*100000);
int width=(int)(Math.random()*2000000);
int result=obj.findArea(height, width);
Assert.assertTrue(verifyArea(height, width, result));
Assert.assertTrue(verifyHeight(height, width, result));
}
}
5. //Generate List
for (List<Integer> any : someLists(integers())) {
System.out.println(any);
}
//Generate array
for (Integer[] arr : someArrays(integers(), Integer.class)) {
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i]);
}
}
//Generate Key Value where value is lis of value
for (Pair<Integer, List<Integer>> any : somePairs(integers(),
lists(integers()))) {
System.out.println("Checking for Value" + any);
}
Different Types of Values Which we can generate
6. //Generate Key Value where value is lis of value
for (Pair<Integer, Integer> any : somePairs(integers(),
integers())) {
System.out.println("Checking for Value" + any);
}
//Generate list of strings
for(List<String> str: someLists(strings())){
System.out.println(str);
}
//Generate unique strings
for(String str: someUniqueValues(strings())){
System.out.println(str);
}
////Generate Sorted list
for(List<Integer> sortedList:someSortedLists(integers())){
System.out.println(sortedList);
}
Different Types of Values Which we can generate
7. //Generate unique string
for(String uniqueStr:someUniqueValues(strings())){
System.out.println(uniqueStr);
}
//Generate Non empty string
for(String uniqueStr:someUniqueValues(nonEmptyStrings())){
System.out.println(uniqueStr);
}
for(Set<Set<String>> map:someSets(sets(strings()))){
System.out.println(map);
}
Different Types of Values Which we can generate
8. package quickcheck;
public class OfferCalculation {
public int calculateAmount(int amount, int offeramount){
return amount-offeramount;
}
public int calculateConvFee(int amount, int conFee){
return amount+conFee;
}
public int calculatefinalAmount(int amount, int confee, int
discount){
return amount-discount+confee;
}
}
Offer Calculation Example
9. @Test
public void testOffer(){
OfferCalculation offer=new OfferCalculation();
SoftAssert soft=new SoftAssert();
boolean flag=false;
for (Pair<Integer, List<Integer>> any :
somePairs(integers(), lists(integers()))) {
System.out.println("Checking for Value"+ any);
for(int i=0;i<any.getSecond().size();i++){
if(offer.calculateAmount(any.getFirst(),
any.getSecond().get(i))>0) flag=true;
soft.assertTrue(flag);
}
}
}
10. @Test
public void testOfferConv(){
OfferCalculation offer=new OfferCalculation();
SoftAssert soft=new SoftAssert();
boolean flag=false;
for (Pair<Integer, List<Integer>> any :
somePairs(integers(), lists(integers()))) {
System.out.println("Checking for Value"+ any);
for(int i=0;i<any.getSecond().size();i++){
int amount= offer.calculateConvFee(any.getFirst(),
any.getSecond().get(i));
if(amount>any.getFirst()) flag=true;
soft.assertTrue(flag);
}
}
}
11. @Test
public void testOfferConvAndDiscount(){
OfferCalculation offer=new OfferCalculation();
SoftAssert soft=new SoftAssert();
boolean flag=false;
for (Pair<Integer, List<Integer>> any :
somePairs(integers(), lists(integers()))) {
System.out.println("Checking for Value"+ any);
for(int i=0;i<any.getSecond().size();i++){
int amount= offer.calculatefinalAmount(any.getFirst(),
any.getSecond().get(i),any.getSecond().get(i+1));
if(amount>0) flag=true;
soft.assertTrue(flag);
}
}
}
12. List<Integer> list;
double meanvalue=0;
double variance=0.0;
double standardDeviation=0.0;
/**
* calculate Mean value.
* @param list
* @return
*/
public double calculateMean(List<Integer> list){
int sum=0;
this.list=list;
for(int i=0;i<list.size();i++){
sum=sum+list.get(i);
}
meanvalue=sum/list.size();
return meanvalue;
}
Mean, Variance and Standard Deviation Example
13. /**
* Calcualte Variance
* @return
*/
public double calcualteVariance(){
for(int i=0;i<list.size();i++){
variance=variance+Math.pow(list.get(i)-meanvalue, 2);
}
variance=variance/list.size();
return variance;
}
/**
* Calcualteb Standard deviation
* @return
*/
public double calculateStandardDeviation(){
return Math.sqrt(variance);
}
Mean, Variance and Standard Deviation Example
14. @Test
public void testMeanCalculation() {
boolean flag;
for (List<Integer> any : someLists(integers(0, 10))) {
System.out.println("Checking for Value" + any);
VarianceCalcualtion var = new VarianceCalcualtion();
double meanValue = var.calculateMean(any);
Collections.sort(any);
int least = any.get(0);
int max = any.get(any.size() - 1);
if (meanValue < max && meanValue > least)
flag = true;
else
flag = false;
Assert.assertTrue(flag);
}
}
Mean, Variance and Standard Deviation Example
15. @Test
public void testMeanCalculationForNegativeValues(){
boolean flag;
for (List<Integer> any : someLists(integers(Integer.MIN_VALUE, 0))) {
System.out.println("Checking for Value" + any);
VarianceCalcualtion var = new VarianceCalcualtion();
double meanValue = var.calculateMean(any);
Collections.sort(any);
int least = any.get(0);
int max = any.get(any.size() - 1);
if (meanValue > max && meanValue < least)
flag = true;
else
flag = false;
Assert.assertTrue(flag);
}
}
Mean, Variance and Standard Deviation Example
16. @Test
public void testVariance(){
SoftAssert soft=new SoftAssert();
boolean flag;
for (List<Integer> any : someLists(integers(0, 1000000))) {
System.out.println("Checking for Value" + any);
VarianceCalcualtion var = new VarianceCalcualtion();
double meanValue = var.calculateMean(any);
double varianceValue=var.calcualteVariance();
if (varianceValue>meanValue)
flag = true;
else
flag = false;
soft.assertTrue(flag);
}
}
Mean, Variance and Standard Deviation Example
17. @Test
public void testSD() {
SoftAssert soft = new SoftAssert();
boolean flag;
for (List<Integer> any : someLists(integers(0, 1000000))) {
System.out.println("Checking for Value" + any);
VarianceCalcualtion var = new VarianceCalcualtion();
double meanValue = var.calculateMean(any);
double varianceValue = var.calcualteVariance();
double sd = var.calculateStandardDeviation();
if (varianceValue > meanValue && sd < meanValue && sd < varianceValue)
flag = true;
else
flag = false;
soft.assertTrue(flag);
}
}
Mean, Variance and Standard Deviation Example
18. <?php
use ErisGenerator;
use ErisTestTrait;
class AlwaysFailsTest extends PHPUnit_Framework_TestCase
{
use TestTrait;
public function testFailsNoMatterWhatIsTheInput()
{
$this->forAll(
Generatorelements(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'])
)
->then(function ($someChar) {
$this->fail("This test fails by design. '$someChar' was passed in");
});
}
}
Quick check in PHP
20. use std::cmp::Ord;
use rand;
use super::{QuickCheck, StdGen, TestResult, quickcheck};
#[test]
fn prop_oob() {
fn prop() -> bool {
let zero: Vec<bool> = vec![];
zero[0]
}
match QuickCheck::new().quicktest(prop as fn() -> bool) {
Ok(n) => panic!("prop_oob should fail with a runtime error
but instead it passed {} tests.", n),
_ => return,
}
}
Quick check in Rust