An introduction on testing Node.js code. Covers frontend (UI) testing, backend unit tests and code coverage. Also mentions how to use a Makefile to run frontend and backend tests at the same time.

1. Testing
with
1

2. Self introduction
Jonathan Waller
2

3. Content
What is Node.js?
Testing the code
Checking test coverage
Testing the user interface
Pulling it all together
3

4. WHAT IS NODE.JS?
4

5. What is Node.js?
example.js
var
http
=
require('http');
http.createServer(function
(request,
response)
{
response.writeHead(200,
{'Content-­‐Type':
'text/plain'});
response.end('Hello
Worldn');
}).listen(8080);
console.log('Server
running
at
http://127.0.0.1:8080/');
Running it
$
node
example.js
Server
running
at
http://127.0.0.1:8080/
5

6. Node is non-blocking
Blocking code
var
fileContents1
=
fs.readFileSync('file1.txt');
console.log(fileContents1);
var
fileContents2
=
fs.readFileSync('file2.txt');
console.log(fileContents2);
0s 5s 10s
6

7. Node is non-blocking
Non-blocking code
var
callback
=
function(err,
fileContents){
console.log(fileContents);
}
fs.readFile('file1.txt',
callback);
fs.readFile('file2.txt',
callback);
0s 5s 10s
7

8. $
node
example.js
8

9. TESTING THE CODE
9

10. Testing the code
describe('file.js',
function()
{
describe('functionName',
function()
{
it('action',
function()
{
...
MOCHA
expect(myObject.id).to.be(undefined);
expect(myObject).to.eql({
a:
'b'
})
expect(myVariable1).to.be.a('number');
expect(myVariable2).to.be.an('array');
EXPECT.JS
10

11. 11

12. TESTING SYNCHRONOUS CODE 1
var
fileContents1
=
fs.readFileSync('file1.txt');
console.log(fileContents1); SYNC_EXAMPLE.JS
var
fileContents2
=
fs.readFileSync('file2.txt');
console.log(fileContents2);
function
readFile1(){
return
fs.readFileSync('file1.txt'); SYNC_EXAMPLE.JS
}
function
readFile2(){
return
fs.readFileSync('file2.txt');
} var
sync_example
=
require(‘./sync_example’);
modules.exports.readFile1
=
readFile1;
modules.exports.readFile2
=
readFile2;
TEST/SYNC_EXAMPLE.JS
12

13. TESTING SYNCHRONOUS CODE 2
function
readFile1(){
return
fs.readFileSync('file1.txt'); SYNC_EXAMPLE.JS
}
function
readFile2(){
return
fs.readFileSync('file2.txt');
}
modules.exports.readFile1
=
readFile1;
modules.exports.readFile2
=
readFile2;
var
sync_example
=
require(‘../sync_example’);
TEST/SYNC_EXAMPLE.JS
describe('sync_example.js',
function()
{
describe('readFile1',
function()
{
it('reads
the
content
of
the
file',
function()
{
var
fileContents1
=
sync_example.readFile1();
expect(fileContents1.length).to.be.greaterThan(0);
});
});
describe('readFile2',
function()
{
it('reads
the
content
of
the
file',
function()
{
var
fileContents2
=
sync_example.readFile2();
expect(fileContents2.length).to.be.greaterThan(0);
});
});
});
13

14. TESTING ASYNCHRONOUS CODE 1
var
callback
=
function(err,
fileContents){
console.log(fileContents); ASYNC_EXAMPLE.JS
}
fs.readFile('file1.txt',
callback);
fs.readFile('file2.txt',
callback);
function
readFile1(callback){
fs.readFile('file1.txt',
callback); ASYNC_EXAMPLE.JS
}
function
readFile2(callback){
fs.readFile('file2.txt',
callback);
}
modules.exports.readFile1
=
readFile1;
modules.exports.readFile2
=
readFile2;
14

15. TESTING ASYNCHRONOUS CODE 2
function
readFile1(callback){
fs.readFile('file1.txt',
callback); ASYNC_EXAMPLE.JS
}
function
readFile2(callback){
fs.readFile('file2.txt',
callback);
}
modules.exports.readFile1
=
readFile1;
modules.exports.readFile2
=
readFile2;
describe('async_example.js',
function()
{
describe('readFile1',
function()
{ TEST/ASYNC_EXAMPLE.JS
it('reads
the
content
of
the
file',
function(done)
{
async_example.readFile1(function(err,fileContents1){
expect(fileContents1.length).to.be.greaterThan(0);
done();
});
});
});
describe('readFile2',
function()
{
it('reads
the
content
of
the
file',
function(done)
{
async_example.readFile2(function(err,fileContents2){
expect(fileContents2.length).to.be.greaterThan(0);
done();
});
});
});
});
15

16. TESTING ASYNCHRONOUS CODE 3
async_example.readFile1(function(err,fileContents1){
expect(fileContents1.length).to.be.greaterThan(0);
done();
});
=
var
callback1
=
function(err,fileContents1){
expect(fileContents1.length).to.be.greaterThan(0);
done();
}
async_example.readFile1(callback1);
16

17. $
mocha
test/example.js
-­‐r
expect.js
17

18. JSCoverage
CHECKING TEST COVERAGE
18

19. 19

20. Checking test coverage
JSCoverage
$
jscoverage
index.js
json-cov
20

21. Checking test coverage
Instrumenting JS file
$
jscoverage
index.js
Running tests (Running the instrumented code)
$
mocha
test/index.js
-­‐R
json-­‐cov
>
coverage.html
21

22. SpookyJS
TESTING THE USER INTERFACE
22

23. UI testing
SpookyJS is a SpookyJS
scriptable web testing
framework for Mocha CasperJS
Wrapper for CasperJs
and PhantomJS
Uses WebKit, so
WEBKIT
supports client-side
Javascript
23

24. var
Spooky
=
require('spooky');
var
spooky
=
new
Spooky(
{
SAMPLE SPOOKY SCRIPT
child:
{
port:
8080,
script:
'./lib/bootstrap.js',
//Loads
casperJS
spooky_lib:
'./node_modules'
}
},
function
(err,
error,
response)
{
if
(err
||
error)
{
var
e
=
new
Error('Failed
to
initialize
SpookyJS');
e.details
=
err
||
error;
throw
e;
}
spooky.on('error',
function
(e)
{console.error(e);});
spooky.on('console',
function
(line)
{console.log(line);});
spooky.start();
spooky.then(function
(){
this.echo('Hello,
this
is
SpookyJS');
});
spooky.open('http://www.google.com/');
spooky.then(function
()
{
this.echo('Now
viewing:
'
+
this.getCurrentUrl());
});
spooky.run();
}
);
24

25. var
util
=
require('util');
var
expect
=
require('expect.js');
describe("Test
that
SpookyJS
is
working",
function
()
{
var
context
=
{};
TEST/FRONTEND.JS
var
hooks
=
require('../util/hooks');
before(hooks.before(context));
describe('Test
that
SpookyJS
can
navigate
to
Google',
function
()
{
it('navigates
to
google.com,
and
returns
the
current
url',
function
(done)
{
context.spooky.start();
context.spooky.then(function
(){
this.echo('Hello,
this
is
SpookyJS');
});
context.spooky.open('http://www.google.com/');
context.spooky.then(function
()
{
this.echo(this.getCurrentUrl());
});
function
onConsole(line)
{
if
(line
===
'http://www.google.com/')
{
context.spooky.removeListener('console',
onConsole);
done();
return;
}
}
context.spooky.on('console',
onConsole);
context.spooky.run();
});
});
after(hooks.after(context));
});
25

26. $
mocha
test/frontend/example.js
-­‐r
expect.js
26

27. $
make
test
PULLING IT ALL TOGETHER
27

28. Make: Folder structure
testbackend:
@mocha
$$(find
test/backend
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
...など
28

29. Testing the backend
Makefile
testbackend:
@./node_modules/.bin/mocha
$$(find
test/backend
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
Run tests
$
make
testbackend
29

30. Checking test coverage
Makefile
coverage:
@echo
'Checking
test
code
coverage...'
#Cleaning
up
@rm
-­‐rf
_src-­‐with-­‐coverage/
&&
rm
-­‐rf
_test-­‐with-­‐coverage/
#Instrumenting
code
@./node_modules/jscoverage/jscoverage
src
_src-­‐with-­‐coverage
#Creating
tests
for
instrumented
code
@cp
-­‐r
test
_test-­‐with-­‐coverage
@find
_test-­‐with-­‐coverage
-­‐name
'*.js'
-­‐exec
sed
-­‐i
''
's//src///_src-­‐with-­‐coverage//g'
"{}"
;
#Running
tests...
@./node_modules/.bin/mocha
$$(find
_test-­‐with-­‐coverage
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
html-­‐cov
>
coverage.html
#Cleaning
up
@rm
-­‐rf
_src-­‐with-­‐coverage/
&&
rm
-­‐rf
_test-­‐with-­‐coverage/
@echo
'Done.
Result
written
to
coverage.html.'
Check test coverage
$
make
coverage
30

31. 31

32. Testing the frontend
Makefile
test:
@./node_modules/.bin/mocha
$$(find
test/frontend
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
Run tests
$
make
testfrontend
32

33. Makefile
testbackend:
@./node_modules/.bin/mocha
$$(find
test/backend
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
testfrontend:
@./node_modules/.bin/mocha
$$(find
test/frontend
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
coverage:
@echo
'Checking
test
code
coverage...'
...
@echo
'Done.
Result
written
to
coverage.html.'
test:
@./node_modules/.bin/mocha
$$(find
test/
-­‐name
"*.js")
-­‐r
expect.js
-­‐R
spec
all:
test
coverage
@echo
'Tested
frontend
and
backend.
Coverage
doc
saved
to
coverage.html.'
Run all tests
$
make
test
Run all tests + show test coverage
$
make
all
33

34. Summary
Node.js is Javascript on the server.
Unit testing with Mocha + Expect.js
Checking coverage with JSCoverage
User interface testing with SpookyJS
Running everything with Make
34

35. Thank you
ありがとうございました
35

36. Contact Jonathan
@jonwaller
facebook.com/jonwaller0
gplus.to/jonwaller
www.jonwaller.net/ja/
36

37. References
Node.js
http://nodejs.org/
Unit testing (Mocha)
http://visionmedia.github.com/mocha/
Test coverage
http://tjholowaychuk.com/post/18175682663/mocha-test-coverage
User interface testing
http://casperjs.org/
https://github.com/WaterfallEngineering/SpookyJS
Other useful stuff
https://npmjs.org/ - Learn about commonly used node packages
http://jenkins-ci.org/ - Set up continuous integration (e.g. Automatically testing when you commit)
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