The--node.js of the front end to crawl and Roll (ii)

This article mainly studies:

• Test framework Mocha;
• Assertion Library: should;
• Test rate Coverage Tool Istanbul;

Create and enter Lesson3:

mkdir Lesson3 && Lesson3

Create a main.js and write a test function:

varFibonacci =function(n) {if(typeofN!== ' number '){        Throw NewError (' n should be a number ')    }    if(N < 0){        Throw NewError (' n should >= 0 ')    }    if(N > 10){        Throw NewError (' N should <= 10 ')    }    if(n = = 0){        return0    }    if(n = = 1){        return1    }    returnFibonacci (n-1) + Fibonacci (n-2)}if(Require.main = = =module) {    varn = number (process.argv[2]) Console.log (' Fibonacci (' + n + ') is ', Fibonacci (n))} Exports.fibonacci= Fibonacci

Lesson3 Create the Test folder and create the Main.test.js:

mkdir Test && CD test && echo.>main.test.js

Write test cases in Main.test.js:

varMain = require ('.. /main ')varshould = require (' should ')) describe (' Test/main.test.js ',function() {It (' Should equal 0 when n = = = 0 ',function() {Main.fibonacci (0). should.equal (0)}) it (' Should equal 1 when n = = = 1 ',function() {Main.fibonacci (1). should.equal (1)}) it (' should equal when n = = = 10 ',function() {Main.fibonacci (). Should.equal (55)}) it (' Should throw when n > 10 ',function (){    (function() {Main.fibonacci (11)}). should.Throw(' N should <= 10 ')}) it (' Should throw when n < 0 ',function(){        (function() {Main.fibonacci (-1)}). should.Throw(' N should >= 0 ')}) it (' Should throw when n isnt number ',function(){        (function() {Main.fibonacci (' Tease ')}). should.Throw(' n should be a number ')    })})

CMD output:

Mocha

Complete the test as shown:

Install a Istanbul:

CNPM I Istanbul-g

Perform:

Istanbul cover _mocha

(Note: If the window does not find the _mocha file error, find the location of your computer in the Mocha installation directory of the _mocha file replacement _mocha, for example: Istanbul cover c:\users\[user name]\appdata\roaming \npm\node_modules\mocha\bin\_mocha)

As you can see, the branch coverage is 91.67% and the line coverage is 87.5%.

The--node.js of the front end to crawl and Roll (ii)