JFixture


Source link: https://github.com/FlexTradeUKLtd/jfixture

JFixture

JFixture is an open source library based on the popular .NET library, AutoFixture.

Description

JFixture is a Java library to assist in the writing of Unit Tests, particularly when following Test Driven Development. It generates types based on the concept of 'constrained non-determinism', which is an implementation of the Generated Value xUnit test pattern.

Overview

A traditional unit test cycle following the method of Triangulation would result in a number of similar looking unit tests that look like 'Tests by example'.

'Tests by example' will contain hard coded values, ( String orderId = "ABCD";) in the Arrange or Act phase of a unit test and repeat that value in the Assert phase. This causes tests to read like examples ("The id passed to the logger should be "ABCD"), rather than tests by specification ("The id passed to the logger should be the same id as the Order I've created"). This effect can be reduced by factoring the values into fields or variables, but this just hides the problem rather than fixing it.

To write 'tests by specification' the input shouldn't be known at the time of writing the test, that is, the input should be generated at run time ( String id = createId(); ). This forces us to avoid repeated test cases and triangulate on correct behaviour much quicker. Tests and code are forced to focus on the semantic representation of the code (the Id) rather than the syntactic representation ("ABCD"). In the previous example createId() could return a new UUID so we can't hard code any values in either the test or the production code.

This is called non-determinism.

Ordinarily the thought of non-determinism inside a unit test should invoke fear. We're aware of the perils of using random numbers, threading, file system etc, so creating unit tests with non-deterministic input would seem to go against the grain. This is a valid concern for truly randomised data, but if we constrain the input to be within the same Equivalence Class we can be confident that our input is valid for each test run even though specific values may vary. As an example, if we always generate strings that will never be empty or null these will almost certainly be in the same equivalence class.

This is called constrained non-determinism.

JFixture has been designed to produce input for unit tests following the principle of constrained non-determinism. This allows the developer to focus on the important parts of unit testing rather than choosing arbitrary values for test data.

Implementation

JFixture is an unofficial cousin of the .NET library AutoFixture. It's heavily inspired by the wonderful work produced by the contributors to AutoFixture but with a Java flair. It's not as fully featured as AutoFixture but any .NET developer familiar with the library should feel comfortable using it.

JFixture started off an an internal project developed by FlexTrade UK to fill the gap in Java testing that AutoFixture fills for .NET testing. It's been used internally for a while and a decision was made to open source it for any other Java developers that may find it useful. For this reason there isn't any git commit history prior to open-sourcing because it would be too much work to rewrite history removing any internal references, links, urls etc.

Example Usage

The Cheat Sheet contains most of the information to get started, but here's a quick example.

To create a field as an anonymous value you can leverage JUnit's Rule engine as such,

@Rule public FixtureRule fr = FixtureRule.initFixtures() @Fixture private Order order; 

To create a variable inside a test method simply call,

JFixture fixture = new JFixture();
 Order order = fixture.create(Order.class);
 

Maven

<dependency>  <groupId>com.flextrade.jfixture</groupId>  <artifactId>jfixture</artifactId>  <version>2.7.2</version> </dependency>

Resources

Simple android camera to capture and get bitmaps.

This library helps to implement phone number verification before performing any further operation.

Light version of ButterKnife's concepts.

Apk parser with java, for decoding xml file and getting meta infos from apk file.

AutoLinkTextView is TextView that supports Hashtags (#), Mentions (@), URLs (http://), Phone and Email automatically detecting and ability to handle clicks.

The Gradle Bintray Plugin allows you to publish artifacts to Bintray.

Topics


2D Engines   3D Engines   9-Patch   Action Bars   Activities   ADB   Advertisements   Analytics   Animations   ANR   AOP   API   APK   APT   Architecture   Audio   Autocomplete   Background Processing   Backward Compatibility   Badges   Bar Codes   Benchmarking   Bitmaps   Bluetooth   Blur Effects   Bread Crumbs   BRMS   Browser Extensions   Build Systems   Bundles   Buttons   Caching   Camera   Canvas   Cards   Carousels   Changelog   Checkboxes   Cloud Storages   Color Analysis   Color Pickers   Colors   Comet/Push   Compass Sensors   Conferences   Content Providers   Continuous Integration   Crash Reports   Credit Cards   Credits   CSV   Curl/Flip   Data Binding   Data Generators   Data Structures   Database   Database Browsers   Date &   Debugging   Decompilers   Deep Links   Dependency Injections   Design   Design Patterns   Dex   Dialogs   Distributed Computing   Distribution Platforms   Download Managers   Drawables   Emoji   Emulators   EPUB   Equalizers &   Event Buses   Exception Handling   Face Recognition   Feedback &   File System   File/Directory   Fingerprint   Floating Action   Fonts   Forms   Fragments   FRP   FSM   Functional Programming   Gamepads   Games   Geocaching   Gestures   GIF   Glow Pad   Gradle Plugins   Graphics   Grid Views   Highlighting   HTML   HTTP Mocking   Icons   IDE   IDE Plugins   Image Croppers   Image Loaders   Image Pickers   Image Processing   Image Views   Instrumentation   Intents   Job Schedulers   JSON   Keyboard   Kotlin   Layouts   Library Demos   List View   List Views   Localization   Location   Lock Patterns   Logcat   Logging   Mails   Maps   Markdown   Mathematics   Maven Plugins   MBaaS   Media   Menus   Messaging   MIME   Mobile Web   Native Image   Navigation   NDK   Networking   NFC   NoSQL   Number Pickers   OAuth   Object Mocking   OCR Engines   OpenGL   ORM   Other Pickers   Parallax List   Parcelables   Particle Systems   Password Inputs   PDF   Permissions   Physics Engines   Platforms   Plugin Frameworks   Preferences   Progress Indicators   ProGuard   Properties   Protocol Buffer   Pull To   Purchases   Push/Pull   QR Codes   Quick Return   Radio Buttons   Range Bars   Ratings   Recycler Views   Resources   REST   Ripple Effects   RSS   Screenshots   Scripting   Scroll Views   SDK   Search Inputs   Security   Sensors   Services   Showcase Views   Signatures   Sliding Panels   Snackbars   SOAP   Social Networks   Spannable   Spinners   Splash Screens   SSH   Static Analysis   Status Bars   Styling   SVG   System   Tags   Task Managers   TDD &   Template Engines   Testing   Testing Tools   Text Formatting   Text Views   Text Watchers   Text-to   Toasts   Toolkits For   Tools   Tooltips   Trainings   TV   Twitter   Updaters   USB   User Stories   Utils   Validation   Video   View Adapters   View Pagers   Views   Watch Face   Wearable Data   Wearables   Weather   Web Tools   Web Views   WebRTC   WebSockets   Wheel Widgets   Wi-Fi   Widgets   Windows   Wizards   XML   XMPP   YAML   ZIP Codes