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Matchers

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May 1, 2024 4 minute read

Matchers are a powerful tool for testing the behavior of your code in a variety of scenarios. They allow you to assert that the output of a function or method matches a specific pattern, making it easy to test for expected results and identify any unexpected behavior.

What are Matchers?

Matchers are JavaScript objects that represent a set of conditions that must be met in order for the assertion to pass. They can be used to test for equality, inequality, truthiness, falsiness, and a variety of other conditions.

Matchers are typically used in conjunction with a testing framework like Jest or Jasmine. These frameworks provide a number of built-in matchers that you can use to test your code, and you can also create your own custom matchers to meet your specific needs.

Why Use Matchers?

There are a number of benefits to using matchers in your tests:

Path to Matchers

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We've curated two courses to help you on your path to Matchers. Use these to develop your skills, build background knowledge, and put what you learn to practice.
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Reading list

We've selected ten books that we think will supplement your learning. Use these to develop background knowledge, enrich your coursework, and gain a deeper understanding of the topics covered in Matchers.
Provides a comprehensive overview of pattern matching in F#, covering both the basics and advanced techniques. It is written by Don Syme and Adam Granicz, two of the leading experts on F#.
Provides a comprehensive overview of pattern matching in Rust, covering both the basics and advanced techniques. It is written by Steve Klabnik, a leading expert on Rust.
Provides a comprehensive overview of pattern matching in Swift, covering both the basics and advanced techniques. It is written by Chris Lattner, a leading expert on Swift.
Provides a comprehensive overview of pattern matching in Java, covering both the basics and advanced techniques. It is written by Josh Bloch, a leading expert on Java.
Provides a comprehensive overview of pattern matching in C++, covering both the basics and advanced techniques. It is written by Herb Sutter, a leading expert on C++.
Provides a comprehensive overview of pattern matching in Go, covering both the basics and advanced techniques. It is written by Rob Pike, a leading expert on Go.
Provides a practical guide to pattern matching in C#, with a focus on real-world examples. It is written by Andrew Stellman and Jeremy Likness, two experienced C# developers.
Provides a practical guide to pattern matching in Python, with a focus on real-world examples. It is written by Brian Overland, an experienced Python developer.
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