Clojure functions midje
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This document provides examples of functions in Clojure and summaries of testing tools Midje. It shows: 1. Examples of Clojure functions like areduce to apply an expression to array elements, with-precision to set decimal precision, and with-redefs to temporarily mock function values. 2. A brief overview of the Midje testing tool, including using facts to make tests more readable based on assertions, the syntax using midje.sweet, and features like metaconstants and checkers. 3. How to use Midje with a Clojure project including creating a new project, adding a tasks file, writing tests, and mixing deftest functions with facts.
![areduce
Apply an expression for each array element
user => (defn asum [numbers]
(areduce numbers i ret (float 0)
(+ ret (aget numbers i))))
user=> (asum (float-array [1 2 3]))
6](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-2-320.jpg)
![with-redefs
Mock temporally a value for a function or a variable. Available just in
clojure 1.3
(defn address-lookup []
(does some processing))
user> (with-redefs [address-lookup (fn [] "123 Main St.")]
(println (address-lookup)))
"123 Main St.”
nill](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-4-320.jpg)
![More About Midje
About the sintax
(:use midje.sweet)
(fact
( [some function variable or object to test]) => [assertions])
(fact
(+ 1 2) => 3)](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-12-320.jpg)
![More about Midje
It has the Metaconstants concept.
(defn numerical-reverser [n]
(String/parseInt (string-reverser (str n))))
The function string-reverser doesn't exists. It's provided by test.
(fact
(numerical-reverser 103) => 301
(provided
(string-reverser "103") => "301"))](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-13-320.jpg)
![More About Midje
It has a lot of checkers
(fact #{1 2 3} => (just [odd? odd? Even?])
(fact "as" => (contains [s a] :in-any-order))
(fact "12x" => (has-prefix #"d+"))
(fact "x12" => (has-suffix #"d+"))](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-14-320.jpg)
![More About Midje
It can store the function state
(fact
(function-to-test) => [6 12]
(provided
(function-to-evaluate) =streams=> [ [1 2] [5 10] ] ))](https://image.slidesharecdn.com/clojurefunctions-midje-111115094112-phpapp01/85/Clojure-functions-midje-16-320.jpg)
Clojure functions midje
- 1. Clojure Example Functions ilegra - LDC By Jackson dos Santos
- 2. areduce Apply an expression for each array element user => (defn asum [numbers] (areduce numbers i ret (float 0) (+ ret (aget numbers i)))) user=> (asum (float-array [1 2 3])) 6
- 3. with-precision Set a precision and rounding to work with point decimal values user => (with-precision 20 (/ 1M 3)) 0.33333333333333333333M
- 4. with-redefs Mock temporally a value for a function or a variable. Available just in clojure 1.3 (defn address-lookup [] (does some processing)) user> (with-redefs [address-lookup (fn [] "123 Main St.")] (println (address-lookup))) "123 Main St.” nill
- 9. About Midje
- 10. What is It? It's an API to make your clojure tests more readable . It's based in facts It has a lot of functionality to create test complex test cases
- 11. How to Use It? Create a new project ./cake new midje-evaluation Copy this file to your root project folder https://raw.github.com/marick/Midje/master/examples/cake-midje/tasks.clj Write your tests and install the project cake midje
- 12. More About Midje About the sintax (:use midje.sweet) (fact ( [some function variable or object to test]) => [assertions]) (fact (+ 1 2) => 3)
- 13. More about Midje It has the Metaconstants concept. (defn numerical-reverser [n] (String/parseInt (string-reverser (str n)))) The function string-reverser doesn't exists. It's provided by test. (fact (numerical-reverser 103) => 301 (provided (string-reverser "103") => "301"))
- 14. More About Midje It has a lot of checkers (fact #{1 2 3} => (just [odd? odd? Even?]) (fact "as" => (contains [s a] :in-any-order)) (fact "12x" => (has-prefix #"d+")) (fact "x12" => (has-suffix #"d+"))
- 15. More About Midje You can mix wih def-test functions (:use clojure.test) (:use midje.sweet) (deftest a-clojure-test-test (is (= 1 "I am a deftest expected result."))) (fact (+ 1 2) => 3)
- 16. More About Midje It can store the function state (fact (function-to-test) => [6 12] (provided (function-to-evaluate) =streams=> [ [1 2] [5 10] ] ))