Pragmatic Bookshelf – förlag

Test applications, packages, and libraries large and small with pytest, Python's most powerful testing framework. pytest helps you write tests quickly and keep them readable and maintainable. In this fully revised edition, explore pytest's superpowers - simple asserts, fixtures, parametrization, markers, and plugins - while creating simple tests and test suites against a small database application. Using a robust yet simple fixture model, it's just as easy to write small tests with pytest as it is to scale up to complex functional testing. This book shows you how.

pytest is undeniably the best choice for testing Python projects. It's a full-featured, flexible, and extensible testing framework. pytest's fixture model allows you to share test data and setup procedures across multiple layers of tests. The pytest framework gives you powerful features such as assert rewriting, parametrization, markers, plugins, parallel test execution, and clear test failure reporting - with no boilerplate code.

With simple step-by-step instructions and sample code, this book gets you up to speed quickly on this easy-to-learn yet powerful tool. Write short, maintainable tests that elegantly express what you're testing. Speed up test times by distributing tests across multiple processors and running tests in parallel. Use Python's builtin assert statements instead of awkward assert helper functions to make your tests more readable. Move setup code out of tests and into fixtures to separate setup failures from test failures. Test error conditions and corner cases with expected exception testing, and use one test to run many test cases with parameterized testing. Extend pytest with plugins, connect it to continuous integration systems, and use it in tandem with tox, mock, coverage, and even existing unittest tests.

Write simple, maintainable tests quickly with pytest.

What You Need:

The examples in this book were written using Python 3.10 and pytest 7. pytest 7 supports Python 3.5 and above.

Are you working on a codebase where cost overruns, death marches, and heroic fights with legacy code monsters are the norm? Battle these adversaries with novel ways to identify and prioritize technical debt, based on behavioral data from how developers work with code. And that's just for starters. Because good code involves social design, as well as technical design, you can find surprising dependencies between people and code to resolve coordination bottlenecks among teams. Best of all, the techniques build on behavioral data that you already have: your version-control system. Join the fight for better code!

Use statistics and data science to uncover both problematic code and the behavioral patterns of the developers who build your software. This combination gives you insights you can't get from the code alone. Use these insights to prioritize refactoring needs, measure their effect, find implicit dependencies between different modules, and automatically create knowledge maps of your system based on actual code contributions.

In a radical, much-needed change from common practice, guide organizational decisions with objective data by measuring how well your development teams align with the software architecture. Discover a comprehensive set of practical analysis techniques based on version-control data, where each point is illustrated with a case study from a real-world codebase. Because the techniques are language neutral, you can apply them to your own code no matter what programming language you use. Guide organizational decisions with objective data by measuring how well your development teams align with the software architecture. Apply research findings from social psychology to software development, ensuring you get the tools you need to coach your organization towards better code.

If you're an experienced programmer, software architect, or technical manager, you'll get a new perspective that will change how you work with code.

What You Need:

Accelerate your Rust development with reusable libraries, and build a game development toolkit that helps you quickly create games using the Bevy Engine. Improve your code with testing, benchmarking, and optimization. Unlock Rust's trait and generic metaprogramming systems to develop code that adapts to fit your needs. Customize libraries with feature flags, and customize language syntax with macros. Master concurrency with threads and asynchronous programming. Structure your programs with reusable state management, menus, user interface elements, and asset management. Quickly build games with reusable physics and collision detection. Make your games pop with animations, particles, and rendering tricks, including parallax layering.

Accelerate your Rust development with intermediate to advanced concepts. Build reusable libraries; unleash generics, traits, macros, and more as you level up your Rust skills. Apply your skills to build a game development toolkit that helps you quickly build 2D games without reinventing the wheel when you start a new project.

Each chapter in this book includes hands-on, practical development using intermediate through advanced Rust. Make learning fun by building games as you apply language concepts. Develop several games and build the tools you need to unleash your creativity or apply the concepts to your own Rust projects.

Improve your code with testing, benchmarking, and optimization. Unlock the power of Rust's trait and generic metaprogramming systems to create code that adapts to fit your needs. Customize libraries with feature flags, and customize language syntax with macros. Structure your code with reusable state management, menus, user interface elements, and asset management. Quickly build games with reusable physics and collision detection. Make your games pop with animations, particles, and rendering tricks, including parallax layering.

This book is the ideal follow-up to take the skills you gained in Hands-on Rust to the next level - or it can be read stand-alone once you've mastered basic Rust.

What You Need:

You thought you knew C, but can you solve 25 puzzles in this popular programming language? Noted C programmer and author Dan Gookin provides a series of pointed questions, puzzles, and problems to keep your C programming skills sharp. Each one will provide insight into various aspects of handling strings, numeric operations, and other activities, giving you techniques to take the best advantage of all C has to offer. Challenge yourself, and get to know some powerful tricks and details for writing better, faster, more accurate C code.

Most C programming books present the information sequentially, teaching you the right way to code and only rarely describing what could go wrong. In this book, the goal is to find out what did go wrong - or what potentially goes right. Explore interesting and unusual programming concepts and approaches with small, to-the-point, programs and exercises. Hone your C programming skills and expand your knowledge.

By working through the brain teasers in this book, you'll fill in gaps in your knowledge and work with advanced concepts such as pointers and recursion. All of the teaser topics were selected to give you food for thought, explaining the technical details behind each puzzle. Look at a code sample and try to guess what output it will give. Code it yourself and see the result. Is it what you expected? Then read the author's lighthearted explanation of exactly why the language does what it does, and how you can take advantage of it. You'll come away with a much better understanding of how the language works, and how to use it for efficient and effective programming.

What You Need:

You need to know the basics of coding in C, and have an environment for compiling and executing your C code. Any Windows, MacOS, or Linux system with a C compiler does the job. Use the terminal window for traditional C programming. Or obtain an Integrated Development Enviornment (IDE) such as Visual Studio Code, which contains all the software tools you need: Editor, Compiler, and Output.

Imagine writing Java code that reads like the problem statement, code that's highly expressive, concise, easy to read and modify, and has reduced complexity. With the functional programming capabilities in Java, that's not a fantasy. This book will guide you from the familiar imperative style through the practical aspects of functional programming, using plenty of examples. Apply the techniques you learn to turn highly complex imperative code into elegant and easy-to-understand functional-style code. Updated to the latest version of Java, this edition has four new chapters on error handling, refactoring to functional style, transforming data, and idioms of functional programming.

Don't struggle with the limitations of the imperative style; instead learn to combine object-oriented programming with the functional style to reduce the accidental complexity. Harness the functional programming capabilities of Java to create applications where the program reveals its intentions and your team can quickly understand and modify code to align with changing business requirements. Unlock the power of lambda expressions and the Streams API to turn the oft-written spaghetti code into highly concise, expressive, elegant, and maintainable code. See how Streams make the arduous task of parallelizing code as easy as flipping a switch when superior speed is necessary.

Apply design patterns built around lambda expressions, safely manage resource allocations, use memoization, and learn to transform data into different forms, all while honoring immutability, and providing thread safety to leverage lazy evaluation for efficiency and parallel execution for performance. Move beyond the basics, explore the idioms for writing functional programs. Learn to think functionally by refactoring legacy code into the functional style. And, if your code runs aground due to failures, learn to properly handle errors the functional way.

Don't drown in theory; instead learn the practical functional programming techniques to create superior Java code.

What You Need:

Java version 8 or newer.

Your customers want rock-solid, bug-free software that does exactly what they expect it to do. Yet they can't always articulate their ideas clearly enough for you to turn them into code. You need Cucumber: a testing, communication, and requirements tool-all rolled into one. All the code in this book is updated for Cucumber 2.4, Rails 5, and RSpec 3.5.

Express your customers' wild ideas as a set of clear, executable specifications that everyone on the team can read. Feed those examples into Cucumber and let it guide your development. Build just the right code to keep your customers happy. You can use Cucumber to test almost any system or any platform.

Get started by using the core features of Cucumber and working with Cucumber's Gherkin DSL to describe-in plain language-the behavior your customers want from the system. Then write Ruby code that interprets those plain-language specifications and checks them against your application. Next, consolidate the knowledge you've gained with a worked example, where you'll learn more advanced Cucumber techniques, test asynchronous systems, and test systems that use a database. Recipes highlight some of the most difficult and commonly seen situations the authors have helped teams solve. With these patterns and techniques, test Ajax-heavy web applications with Capybara and Selenium, REST web services, Ruby on Rails applications, command-line applications, legacy applications, and more.

Written by the creator of Cucumber and the co-founders of Cucumber Ltd., this authoritative guide will give you and your team all the knowledge you need to start using Cucumber with confidence.

What You Need:

Windows, Mac OS X (with XCode) or Linux, Ruby 1.9.2 and upwards, Cucumber 2.4, Rails 5, and RSpec 3.5

Drowning in unnecessary complexity, unmanaged state, and tangles of spaghetti code? In the best tradition of Lisp, Clojure gets out of your way so you can focus on expressing simple solutions to hard problems. Clojure cuts through complexity by providing a set of composable tools--immutable data, functions, macros, and the interactive REPL. Written by members of the Clojure core team, this book is the essential, definitive guide to Clojure. This new edition includes information on all the newest features of Clojure, such as transducers and specs.

Clojure joins the flexibility and agility of Lisp with the reach, stability, and performance of Java. Combine Clojure's tools for maximum effectiveness as you work with immutable data, functional programming, and safe concurrency to write programs that solve real-world problems.

Start by reading and understanding Clojure syntax and see how Clojure is evaluated. From there, find out about the sequence abstraction, which combines immutable collections with functional programming to create truly reusable data transformation code. Clojure is a functional language; learn how to write programs in a functional style, and when and how to use recursion to your advantage. Discover Clojure's unique approach to state and identity, techniques for polymorphism and open systems using multimethods and protocols, and how to leverage Clojure's metaprogramming capabilities via macros. Finally, put all the pieces together in a real program.

New to this edition is coverage of Clojure's spec library, one of the most interesting new features of Clojure for describing both data and functions. You can use Clojure spec to validate data, destructure data, explain invalid data, and generate large numbers of tests to verify the correctness of your code.

With this book, you'll learn how to think in Clojure, and how to take advantage of its combined strengths to build powerful programs quickly.

What You Need:

Reactive programming is revolutionary. It makes asynchronous programming clean, intuitive, and robust. Use RxJS 5 to write complex programs in a simple way, and master the Observable: a powerful data type that substitutes callbacks and promises. Think about your programs as streams of data that change and adapt to produce what you want. Manage real-world concurrency and write complex flows of events in your applications with ease. Take advantage of Schedulers to make asynchronous testing easier. The code in this new edition is completely updated for RxJS 5 and ES6.

Create concurrent applications with ease using RxJS 5, a powerful event composition library. Real-world JavaScript applications require you to master asynchronous programming, and chances are that you'll spend more time coordinating asynchronous events than writing actual functionality. This book introduces concepts and tools that will greatly simplify the process of writing asynchronous programs.

Find out about Observables, a unifying data type that simplifies concurrent code and eases the pain of callbacks. Learn how Schedulers change the concept of time itself, making asynchronous testing sane again. Find real-world examples for the browser and Node.js along the way: how about a real-time earthquake visualization in 20 lines of code, or a frantic shoot-'em-up space videogame? You'll also use Cycle.js - a modern, reactive, web framework - to make a new breed of web applications.

By the end of the book, you'll know how to think in a reactive way, and to use RxJS 5 to build complex programs and create amazing reactive user interfaces. You'll also understand how to integrate it with your existing projects and use it with the frameworks you already know. All the code in this new edition has been thoroughly revised and updated for RxJS 5, ES6, and Cycle.js Unified.

What You Need: