Node.js has given JavaScript a new resurgence as a server-side language. No longer just for image rollovers and AJAX, JS is now available as a platform for creating lightning-fast, lightweight, networked applications. In this session, we will move beyond Node’s base web servers and Twitter applications, and into module development: those small, reusable components that are the foundation for every business application on every platform. Learn how to create a module within Node.js, how to test your module and validate functionality, and how to get your creation distributed into the wild. With this knowledge, you can make the next great Node package and become famous.

1. MODULE
DEVELOPMENT

2. What is node.js?
“
Node.js is a platform built on
Chrome's JavaScript runtime for
easily building fast, scalable network
applications.
”

4. ./

5. sourceControl
git
init

6. javascriptFiles
mkdir
./lib

7. executableFiles
mkdir
./bin

8. testFiles
mkdir
./test

9. documentationFiles
mkdir
./doc
mkdir
./example
mkdir
./man

10. informationalFiles
touch
./README
touch
./LICENSE
touch
./AUTHOR

11. ./bin
./doc
./example
./lib
./man
./test
singularNouns

12. packageManagement

13. Package Manager

14. github: isaacs/npm
install: comes with node

15. localInstallation
npm install <package>

16. globalInstallation
npm install <package> --global
-g or --global

17. dualInstallation
npm install <package> --link

18. dependencyReferences
npm install <package> --save[-dev]
--save or --save-dev

19. updateDependencies
npm install

20. packageInitialization
npm init

21. $
npm
init
name: (sample-node) Sample
version: (0.0.0) 0.1.0
description: This is a sample module
entry point: (index.js) _

22. author:
Jay
Harris
license:
(BSD)
BSD
About
to
write
to
/Projects/sample-­‐node/package.json:
{
"name":
"Sample",
"version":
"0.1.0",
"description":
"This
is
a
sample
module",
"main":
"index.js",
"scripts":
{
"test":
"echo
"Error:
no
test
specified"
&&
exit
1"
},
"author":
"Jay
Harris",
"license":
"BSD"
}
Is
this
ok?
(yes)
_

23. ./package.json
1 {
"name": "Sample",
2
"version": "0.1.0",
3
"description": "This is a sample module",
4
"main": "index.js",
5
"scripts": {
6
"test": "echo "Error: no tests avail." && exit 1"
7
},
8
"author": "Jay Harris",
9
"license": "BSD"
10
11 }
12
13
14
15
16

24. npm init is additive not destructive

25. moduleCreation

26. module

27. module.exports

28. ./lib/sample.js
1 module.exports.sayHello = function() {
return "Hello World!";
2
3 }
4
5
6
7
8
9
10
11
12
13
14
15
16

29. var
sample
=
require("./lib/sample.js");
//
Returns
'Hello
World!'
sample.sayHello();

30. ./lib/person.js
1 function Person(first, last) {
if (!(this instanceof Person)) {
2
return new Person(first, last);
3
}
4
5
this.firstName = first;
6
this.lastName = last;
7
8
return this;
9
10 }
11
12 module.exports = Person;
13
14
15
16

31. var person = require("./lib/person.js");
// This will return undefined
person.firstName;
// This will return 'Jay'
var jayHarris = new Person('Jay','Harris');
jayHarris.firstName;

32. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
function Person(first, last) {
// ...
}
module.exports = Person;
// This is a public method;
Person.prototype.sayHello = function() {
return _join.call(this, "Hello", this.firstName);
}
// This is a private method
var _join(first, second) {
return first + ' ' + second;
}

33. var
person
=
require("./lib/person.js");
//
This
will
throw
'Has
No
Method'
error
person.sayHello();
//
This
will
return
'Hello
Jay'
var
jayHarris
=
new
Person('Jay','Harris');
jayHarris.sayHello();

34. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
function Person(first, last) {
// ...
}
module.exports = Person;
// This is a static method
module.exports.sayHello = function() {
return "Hello World!";
}
// This is a public instance method;
Person.prototype.sayHello = function() {
return _join.call(this, "Hello", this.firstName);
}
// This is a private method
var _join(first, second) {
return first + ' ' + second;
}

35. var
person
=
require("./lib/person.js");
//
This
will
return
'Hello
World!'
person.sayHello();
//
This
will
return
'Hello
Jay'
var
jayHarris
=
new
Person('Jay','Harris');
jayHarris.sayHello();

36. eventEmitter

37. var
EventEmitter
=
require('events').EventEmitter;

38. EventEmitter.call(this);

39. var
util
=
require('util');
//
...
util.inherits(MyClass,
EventEmitter);

40. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var EventEmitter = require('events').EventEmitter
, util = require('util');
function Person(first, last) {
// ...
EventEmitter.call(this);
// ...
}
util.inherits(Person, EventEmitter);
Person.prototype.goToBed = function() {
this.emit("sleep");
}

41. var
person
=
require("./person.js");
//
This
will
return
'Hello
Jay'
var
jayHarris
=
new
Person('Jay','Harris');
jayHarris.on("sleep",
function()
{
console.log("Goodnight,
Jay");
}
jayHarris.goToBed();
//
Output
'Goodnight,
Jay'

42. testingNode.js

43. “
TDD is to coding style as yoga is
to posture. Even when you're not
actively practicing, having done so
colors your whole life healthier.
”
j. kerr

44. assertingCorrectness

45. var
assert
=
require('assert');

46. assert(value)
.ok(value)
.equal(actual,
expected)
.notEqual(actual,
expected)
.deepEqual(actual,
expected)
.notDeepEqual(actual,
expected)
.strictEqual(actual,
expected)
.notStrictEqual(actual,
expected)
.throws(block,
[error])
.doesNotThrow(block,
[error])
.ifError(value)

47. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var assert = require('assert');
// Will pass
assert.ok(true);
// Will throw an exception
assert.ok(false);

48. 1 var assert = require('assert');
2
3 // Will throw 'false == true' error
4 assert.ok(typeof 'hello' === 'number');
5
6
7
8
9
10
11
12
13
14
15
16
17
18

49. $
node
test.js
assert.js:104
throw
new
assert.AssertionError({
^
AssertionError:
false
==
true
at
Object.<anonymous>
(my-­‐test.js:7:8)
at
Module._compile
(module.js:449:26)
at
Object.Module._extensions..js
(module.js:467:10)
at
Module.load
(module.js:356:32)
at
Function.Module._load
(module.js:312:12)
at
Module.runMain
(module.js:487:10)
at
process.startup.processNextTick.process._tick...
$
_

50. Chai Assertion Library

51. github: chaijs/chai
install: npm install chai

52. isTrue,
isFalse,
isNull,
isNotNull,
isUndefined,
isDefined,
isFunction,
isNotFunction,
isArray,
isNotArray,
isBoolean,
isNotBoolean,
isNumber,
isNotNumber,
isString,
isNotString,
include,
lengthOf,
operator,
closeTo
isObject,
isNotObject,
typeOf,
notTypeOf,
instanceOf,
notInstanceOf,
match,
notMatch,
property,
notProperty,
deepProperty,
notDeepProperty,
propertyVal,
propertyNotVal,
deepPropertyVal,
deepPropertyNotVal,
additional
assertions

53. var
assert
=
require('chai').assert;

54. 1 var assert = require('chai').assert;
2
3 // Will throw 'expected 'hello' to be a number'
4 assert.isNumber('hello');
5
6
7
8
9
10
11
12
13
14
15
16
17
18

55. $
node
test.js
expected
'hello'
to
be
a
number
$
_

56. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var chai
= require('chai')
, assert = chai.assert;
chai.Assertion.includeStack = true;
// Will throw and display stack
assert.isNumber('hello');

57. expectAssertions

58. assertSyntax
assert.isObject(person);
assert.property(person,
"age");
assert.isNumber(person.age);
assert.equals(person.age,
34);
expectSyntax
expect(person).to.be.an('object');
.with.property('age')
.that.is.a('number')
.that.equals(34);

59. var
expect
=
require('chai').expect;

60. assertionChains
for readability

61. expect(person).to.exist
.and.be.an('object')
.with.property('age')
.that.is.to.exist
.and.is.a('number')
.and.equals(34);

62. .to
.be
.been
.is
.that
.and
.have
.with
syntaxSugar
for readability

63. expect(person).to.exist
.and.be.an('object')
.with.property('age')
.that.is.to.exist
.and.is.a('number')
.and.equals(34);

64. expect(person).to.exist
.and.be.an('object')
.with.property('age')
.that.is.to.exist
.and.is.a('number')
.and.equals(34);

65. .property
subjectChange
from original object

66. expect(person)
.that.is.an('object')
.with.property('address')
.that.is.an('object')
.with.property('city')
.that.is.a('string')
.and.equals('Detroit')

67. testingFramework

68. mocha
simple, flexible, fun

69. mocha
github: visionmedia/mocha
install: npm install -g mocha

70. $
npm
install
-­‐g
mocha
$
mkdir
test
$
mocha
✔
0
tests
complete
(1ms)
$

71. var
mocha
=
require('mocha');

72. bddSyntax
describe('Testing
out
this
thing',
function()
{
it('should
do
stuff',
function()
{
//
Assertion
tests
});
});

73. ./test/my-test.js
1 var assert = require('assert');
2
3 describe('Assertions', function() {
it('should pass on truthiness', function() {
4
assert.ok(true);
5
});
6
it('should fail on falsiness', function() {
7
assert.ok(false);
8
});
9
10 });
11
12
13
14
15
16

74. $
mocha
-­‐-­‐reporter
spec
Assertions
✓
should
pass
on
truthiness
1)
should
fail
on
falsiness
✖
1
of
2
tests
failed:
1)
Assertions
should
fail
on
falsiness:
AssertionError:
false
==
true
at
(stack
trace
omitted
for
brevity)
$
_

75. groupedTests

76. groupSyntax
describe('Testing
out
this
thing',
function()
{
describe('with
a
subset
of
this
other
thing',
function()
{
it('should
do
stuff',
function()
{
//
Assertion
tests
});
});
});

77. 1 var expect = require('chai').expect;
2
3 describe('Assertions', function() {
describe('on equality', function() {
4
it('should pass on truthiness', function() {
5
expect(true).is.true;
6
});
7
it('should pass on falsiness', function() {
8
expect(false).is.false;
9
});
10
});
11
describe('on type', function() {
12
it('should pass on number', function() {
13
expect(5).is.a('number');
14
});
15
});
16
17 });
18

78. $
mocha
-­‐-­‐reporter
spec
Assertions
of
equality
✓
should
pass
on
truthiness
✓
should
pass
on
falsiness
on
type
✓
should
pass
on
number
✔
3
tests
complete
(6ms)
$
_

79. pendingTests

80. pendingSyntax
describe('Testing
out
this
thing',
function()
{
describe('with
a
subset
of
this
other
thing',
function()
{
it('should
do
stuff
someday');
});
});

81. 1 var assert = require('chai').assert;
2
3 describe('Assertions', function() {
describe('of truthiness', function() {
4
it('should pass on truthiness', function() {
5
expect(true).is.true;
6
});
7
it('should pass on falsiness', function() {
8
expect(false).is.false;
9
});
10
});
11
describe('of type', function() {
12
it('should pass on number', function() {
13
expect(5).is.a('number');
14
});
15
it('should pass on object');
16
});
17
18 });

82. $
mocha
-­‐-­‐reporter
spec
Assertions
of
truthiness
✓
should
pass
on
truthiness
✓
should
pass
on
falsiness
of
type
✓
should
pass
on
number
-­‐
should
pass
on
object
✔
4
tests
complete
(6ms)
•
1
test
pending
$
_

83. skippedTests

84. skipSyntax
describe('Testing
out
this
thing',
function()
{
it.skip('should
be
skipped',
function()
{
//
Assertion
tests
});
});
describe.skip('This
entire
suite
will
be
skipped',
function()
{
it('should
do
stuff',
function()
{
//
Assertion
tests
});
});

85. 1 describe('Assertions', function() {
describe('of truthiness', function() {
2
it('should pass on truthiness', function() {
3
assert.isTrue(true);
4
});
5
it('should pass on falsiness', function() {
6
assert.isFalse(false);
7
});
8
});
9
describe('of type', function() {
10
it.skip('should pass on number', function() {
11
assert.isNumber(5);
12
});
13
it('should pass on object');
14
});
15
16 });
17
18

86. $
make
test
Assertions
of
truthiness
✓
should
pass
on
truthiness
✓
should
pass
on
falsiness
of
type
-­‐
should
pass
on
number
-­‐
should
pass
on
object
✔
4
tests
complete
(6ms)
•
2
test
pending
$
_

87. setupTeardown

88. before();
beforeEach();
after();
afterEach();

89. setupTeardown
describe('Testing
out
this
thing',
function()
{
before(function(){
//
...
};
describe('with
a
subset
of
that
thing',
function()
{
it('should
do
stuff',
function()
{
//
Assertion
tests
});
afterEach(function(){
//
...
};
});
});

90. asynchronousTests

91. asynchronousSyntax
it('should
not
error',
function(done)
{
search.find("Apples",
done);
});

92. asynchronousSyntax
it('should
not
error',
function(done)
{
search.find("Apples",
done);
});
it('should
return
2
items',
function(done)
{
search.find("Apples",
function(err,
res)
{
if
(err)
return
done(err);
res.should.have.length(2);
done();
});
});

93. All Mocha functions accept this callback

94. 1 describe('When searching for Apples', function(done) {
before(function(done){
2
items.save(['fiji apples',
3
'empire apples'], done);
4
});
5
it('should not error', function(done) {
6
search.find("Apples", done);
7
});
8
it('should return 2 items', function(done) {
9
search.find("Apples", function(err, res) {
10
if (err) return done(err);
11
res.should.have.length(2);
12
done();
13
});
14
});
15
16 });
17
18

95. simplifyExecution

96. $
mocha
<args>
should be simplified to
$
make
test
and
$
npm
test

97. ./makefile
1 # Makefile for sample module
2
3 test:
mocha --reporter spec --ui bdd
4
5
6
7
8 .PHONY: test
9
10
11
12
13
14
15
16

98. ./makefile
1 # Makefile for sample module
2
3 test:
mocha
4
--reporter spec
5
--ui bdd
6
7
8 .PHONY: test
9
10
11
12
13
14
15
16

99. $
make
test
Assertions
✓
should
pass
on
truthiness
1)
should
fail
on
falsiness
✖
1
of
2
tests
failed:
1)
Assertions
should
fail
on
falsiness:
AssertionError:
false
==
true
at
(stack
trace
omitted
for
brevity)
$
_

100. ./package.json
1 {
"name": "sample",
2
"version": "0.1.0",
3
"scripts": {
4
"test": "make test"
5
}
6
7 }
8
9
10
11
12
13
14
15
16

101. $
npm
test
Assertions
✓
should
pass
on
truthiness
1)
should
fail
on
falsiness
✖
1
of
2
tests
failed:
1)
Assertions
should
fail
on
falsiness:
AssertionError:
false
==
true
at
(stack
trace
omitted
for
brevity)
$
_

102. eliminate global dependency
$
npm
install
mocha
-­‐-­‐link

103. 1 test:
@./node_modules/.bin/mocha
2
--reporter spec
3
--ui bdd
4
5
6 .PHONY: test
7
8
9
10
11
12
13
14
15
16
17
18

104. update dev dependencies
$
npm
install
mocha
-­‐-­‐save-­‐dev
$
npm
install
chai
-­‐-­‐save-­‐dev

105. $
npm
install
mocha
-­‐-­‐save-­‐dev
$
npm
install
chai
-­‐-­‐save-­‐dev
$
git
diff
package.json
diff
-­‐-­‐git
a/package.json
b/package.json
index
439cf44..3609bb9
100644
-­‐-­‐-­‐
a/package.json
+++
b/package.json
@@
-­‐1,5
+1,7
@@
{
"name":
"sample",
-­‐
"version":
"0.1.0"
+
"version":
"0.1.0",
+
"devDependencies":
{
+
"mocha":
"~1.9.0",
+
"chai":
"~1.6.0"
+
}
}

106. notificationSystems

107. continuousTesting
mocha --watch
-w or --watch

108. $
mocha
-­‐-­‐watch
✔
5
tests
complete
(22ms)
^
watching

109. Growl

110. mac: apple app store
win: growlForWindows.com
also: growlNotify

111. growlNotifications
mocha --growl
-G or --growl

112. ⌘S

113. 1 test:
@./node_modules/.bin/mocha
2
--reporter spec
3
--ui bdd
4
5
6 watch:
@./node_modules/.bin/mocha
7
--reporter min
8
--ui bdd
9
--growl
10
--watch
11
12
13 .PHONY: test watch
14
15
16
17
18

114. mockingObjects

115. JavaScript ships with a mocking framework
...it’s called JavaScript

116. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var me = {firstName: 'Jay'
, lastName: 'Harris'
, getFullName: function() {
return this.firstName +
' ' +
this.lastName; }};
// Returns 'Jay Harris'
me.getFullName();
me.getFullName = function() { return 'John Doe'; };
// Returns 'John Doe'
me.getFullName();

117. nock
HTTP Mocking Library

118. nock
github: flatiron/nock
install: npm install nock

119. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var http = require('http');
var reqOptions = {
host: 'api.twitter.com',
path: '/1/statuses/user_timeline.json?' +
'screen_name=jayharris'
};
// ...
http.request(reqOptions, resCallback).end();
// Returns live Twitter data

120. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
var nock = require('nock');
var twitter = nock('http://api.twitter.com')
.get('/1/statuses/user_timeline.json?'+
'screen_name=jayharris')
.reply(200, "This worked");
// Returns "This worked"
http.request(reqOptions, resCallback).end();

121. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
// Returns live Twitter data
http.request(reqOptions, resCallback).end();
var nock = require('nock');
var twitter = nock('http://api.twitter.com')
.get('/1/statuses/user_timeline.json?'+
'screen_name=jayharris')
.reply(200, "This worked");
// Returns "This worked"
http.request(reqOptions, resCallback).end();
// Returns live Twitter data
http.request(reqOptions, resCallback).end();

122. nock
nock.recorder.rec(
);
nock.recorder.play(
);

123. Sinon.js
Spies, Stubs, & Mocks

124. Sinon.js
github: cjohansen/Sinon.JS
install: npm install sinon

125. versionTesting

126. nvm
Node Version Manager

127. nvm
github: creationix/nvm
github: hakobera/nvmw

128. $
nvm
list
v0.4.0
v0.6.18
v0.8.21
v0.4.7
v0.8.1
v0.10.0
v0.6.0
v0.8.8
current:
v0.8.1
10
-­‐>
0.10.0
(-­‐>
v0.10.0)
4
-­‐>
0.4.7
(-­‐>
v0.4.7)
6
-­‐>
0.6.18
(-­‐>
v0.6.18)
8
-­‐>
0.8.21
(-­‐>
v0.8.21)
default
-­‐>
0.10.0
(-­‐>
v0.10.0)
newest
-­‐>
0.10.0
(-­‐>
v0.10.0)
$
_

129. $
node
-­‐-­‐version
v0.10.0
$
nvm
install
v0.10.6
Now
using
node
v0.10.6
/Users/jayharris/.nvm/v0.10.6/bin/npm
$
node
-­‐-­‐version
v0.10.6
$
_

130. packageDistribution

131. Package Manager

132. filePackaging
./.npmignore

133. userSetup
npm adduser

134. $
npm
adduser
Username:
(jayharris)
jayharris
Password:
Email:
(jay@aranasoft.com)
_

135. $
npm
whoami
jayharris
$
_

136. packagePublish
npm publish

137. {
name:
'morale',
description:
'Async
API
wrapper
for
Morale',
'dist-­‐tags':
{
latest:
'0.2.0'
},
versions:
[
'0.1.0',
'0.1.2',
'0.2.0'
],
maintainers:
'jayharris
<jay@aranasoft.com>',
time:
{
'0.1.0':
'2012-­‐01-­‐23T03:24:59.824Z',
'0.1.2':
'2012-­‐01-­‐25T23:20:52.927Z',
'0.2.0':
'2012-­‐08-­‐13T16:23:28.488Z'
},
author:
'Arana
Software
<info@aranasoft.com>',
repository:
{
type:
'git',
url:
'git://github.com/aranasoft/morale-­‐node.git'
},
users:
{
fgribreau:
true
},
version:
'0.2.0',

138. $
npm
publish
npm
http
PUT
https://registry.npmjs.org/morale
npm
http
409
https://registry.npmjs.org/morale
npm
http
GET
https://registry.npmjs.org/morale
npm
http
200
https://registry.npmjs.org/morale
npm
http
PUT
https://registry.npmjs.org/morale/0.2.1/-­‐tag/latest
npm
http
201
https://registry.npmjs.org/morale/0.2.1/-­‐tag/latest
npm
http
GET
https://registry.npmjs.org/morale
npm
http
200
https://registry.npmjs.org/morale
npm
http
PUT
https://registry.npmjs.org/morale/-­‐/
morale-­‐0.2.1.tgz/-­‐rev/25-­‐c9bbf49ea0bd2a750e257153fab5794b
npm
http
201
https://registry.npmjs.org/morale/-­‐/
morale-­‐0.2.1.tgz/-­‐rev/25-­‐c9bbf49ea0bd2a750e257153fab5794b
+
morale@0.2.1
$
_

139. {
name:
'morale',
description:
'Async
API
wrapper
for
Morale',
'dist-­‐tags':
{
latest:
'0.2.1'
},
versions:
[
'0.1.0',
'0.1.2',
'0.2.0',
'0.2.1'
],
maintainers:
'jayharris
<jay@aranasoft.com>',
time:
{
'0.1.0':
'2012-­‐01-­‐23T03:24:59.824Z',
'0.1.2':
'2012-­‐01-­‐25T23:20:52.927Z',
'0.2.0':
'2012-­‐08-­‐13T16:23:28.488Z',
'0.2.1':
'2012-­‐08-­‐30T19:10:20.133Z'
},
author:
'Arana
Software
<info@aranasoft.com>',
repository:
{
type:
'git',
url:
'git://github.com/aranasoft/morale-­‐node.git'
},

140. privatePackages
{ "private": "true" }

141. ./package.json
1 {
"name": "Sample",
2
"version": "0.1.0",
3
"description": "This is a sample module",
4
"main": "index.js",
5
"scripts": {
6
"test": "echo "Error: no tests avail." && exit 1"
7
},
8
"author": "Jay Harris",
9
"license": "BSD",
10
"private": "true"
11
12 }
13
14
15
16

142. $
npm
publish
npm
ERR!
Error:
This
package
has
been
marked
as
private
npm
ERR!
Remove
the
'private'
field
from
the
package.json
to
publish
it.
$
_

143. versionLockdown
npm shrinkwrap

144. $
npm
shrinkwrap
wrote
npm-­‐shrinkwrap.json
$
_

145. 1 {
"name": "morale",
2
"version": "0.2.1",
3
"dependencies": {
4
"underscore": {
5
"version": "1.3.3"
6
},
7
"mocha": {
8
"version": "1.3.0",
9
"dependencies": {
10
"commander": {
11
"version": "0.6.1"
12
},
13
"growl": {
14
"version": "1.5.1"
15
},
16
"jade": {
17
"version": "0.26.3",
18

146. $
rm
npm-­‐shrinkwrap.json
$
npm
update
$
npm
test
$
npm
shrinkwrap

147. tellEveryone

148. Go make some Awesome

149. jay harris
P R E S I D E N T
jay@aranasoft.com
#nodemoduledev
@jayharris