Nowadays we all seem to be working with small independent services that need to talk with numerous other services. This is a problem because when developing your service, you need to have a working environment—but bringing up all your dependencies is often not an option. In this talk, I will take you through our journey of creating a mock server to increase dev speed, and how it allowed us to write better tests.

1. PEGGY • SENIOR DEVELOPER • ATLASSIAN • @PYKO
Mock servers
Fake all the things!

2. CREATING MOCK SERVERS
WHY USE MOCK SERVERS?
TESTING WITH MOCKS
THINGS TO LOOK OUT FOR
Agenda
THE PROBLEM

3. The problem

15. Simple servers that provide dummy data to
mock or simulate external dependencies.
“
”

16. Why use mock servers?

19. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Isolation

20. Self-contained
Decoupled
Stable

21. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Faster dev loop

22. 127.0.0.1

23. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Better testing

24. Full control
Edge cases
E2E tests

25. Creating mock servers

26. 3rd party libraries
vs
Build your own

27. WireMock
MockServer
and more…

28. Build your own

30. 36 lines of code

34. // Assume all requests are successful
app.post('/rest/billing/1/product/*',
function(req, res) {
res.type('application/json');
res.status(202).send();
});

35. // Assume all requests are successful
app.post('/rest/billing/1/product/*',
function(req, res) {
res.type('application/json');
res.status(202).send();
});

36. // Assume all requests are successful
app.post('/rest/billing/1/product/*',
function(req, res) {
res.type('application/json');
res.status(202).send();
});

37. // Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

38. // Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

39. // Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});
GET /rest/billing/1/instance/pricing

40. GET /rest/billing/1/instance/pricing
// Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

41. get /rest/billing/1/instance/pricing
// Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

42. path = 'instance/pricing-get.json'get instance/pricing
// Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

43. // Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});
require('./instance/pricing-get.json');

44. instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json
require('./instance/pricing-get.json');

45. {
"hostname": "stubbed-host-response",
"active": true,
"currentBillingPeriod": {
"startDate": "2014-05-18",
"endDate": "2014-06-18",
"renewalFrequency": "monthly"
},
…
./instance/pricing-get.json

46. {
"hostname": "stubbed-host-response",
"active": true,
"currentBillingPeriod": {
"startDate": "2014-05-18",
"endDate": "2014-06-18",
"renewalFrequency": "monthly"
},
…
GET /rest/billing/1/instance/pricing

47. instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json

51. instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json

52. instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json

53. POST data

54. instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json
prospective-prices-postData.json

55. // Mock out the APIs.
// Directory path reflects the REST path.
app.all('/rest/billing/1/*', function(req, res) {
var method = req.method.toLowerCase();
var path = req.path.replace('/rest/billing/1/', '') +
'-' + method + '.json';
res.send(require('./' + path));
});

56. app.post('/rest/billing/1/*', function (req, res) {
validatePostData(req);
res.send(getJsonFileForRequest(req, 'post'));
});
app.get('/rest/billing/1/*', function (req, res) {
res.send(getJsonFileForRequest(req, 'get'));
});

57. app.post('/rest/billing/1/*', function (req, res) {
validatePostData(req);
res.send(getJsonFileForRequest(req, 'post'));
});
app.get('/rest/billing/1/*', function (req, res) {
res.send(getJsonFileForRequest(req, 'get'));
});

58. app.post('/rest/billing/1/*', function (req, res) {
validatePostData(req);
res.send(getJsonFileForRequest(req, 'post'));
});
app.get('/rest/billing/1/*', function (req, res) {
res.send(getJsonFileForRequest(req, 'get'));
});

60. scenarios

62. states
all-the-products
annual-cc-noError
annual-cc-paymentError
monthly-cc-expiredCC
monthly-cc-productActivating
monthly-one-product-in-eval
…

63. app.get('/state/:state', function (req, res) {
app.state = req.params.state;
res.redirect('/billing/overview');
});

64. app.get('/state/:state', function (req, res) {
app.state = req.params.state;
res.redirect('/billing/overview');
});
GET /state/all-the-products

65. app.get('/state/:state', function (req, res) {
app.state = req.params.state;
res.redirect(‘/admin/billing/overview');
});
app.state = 'all-the-products'

66. function getJsonFilePath(path, suffix, ignoreState) {
var basePath = '/' + path.replace('/rest/billing/1/', '');
var filePath;
if (app.state && !ignoreState) {
basePath = '/states/' + app.state + basePath;
}
filePath = __dirname + basePath + '-' + suffix + '.json';
return filePath;
}
app.state = 'all-the-products'

67. function getJsonFilePath(path, suffix, ignoreState) {
var basePath = '/' + path.replace('/rest/billing/1/', '');
var filePath;
if (app.state && !ignoreState) {
basePath = '/states/' + app.state + basePath;
}
filePath = __dirname + basePath + '-' + suffix + '.json';
return filePath;
}
app.state = 'all-the-products'

68. states
all-the-products
annual-cc-noError
annual-cc-paymentError
monthly-cc-expiredCC
monthly-cc-productActivating
monthly-one-product-in-eval
…

69. GET /state/all-the-products

70. GET /state/jira-activating

71. GET /state/cc-paymentError

72. 442 lines of code

74. GET /instance/{uuid}/pricing
"headers": {
"uuid": scenarioUuid
}

75. GET /instance/jira-activating/pricing
"headers": {
"uuid": "jira-activating"
}

76. smarter JSON

77. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}

78. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}

79. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys":
["jira-core.ondemand",
"jira-software.ondemand"
"jira-servicedesk.ondemand"]
}
}
},

80. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys":
["jira-core.ondemand",
"jira-software.ondemand"
"jira-servicedesk.ondemand"]
}
}
},

81. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys":
["jira-core.ondemand",
"jira-software.ondemand",
"jira-servicedesk.ondemand"]
}
}
},

82. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}

83. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira-software.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys": ["jira-software.ondemand"]
}
}
}

84. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira-software.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys": ["jira-software.ondemand"]
}
}
}

85. {
"interactions": [
{
"request": {...},
"response": {...}
},
{
"request": {...},
"response": {...}
}
]
}
{
"request": {
"method": "POST",
"contentType": "application/json",
"body": {
"products": ["jira-software.ondemand"]
}
},
"response": {
"status": 200,
"body": {
"productKeys": ["jira-software.ondemand"]
}
}
}

86. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace

87. Testing with mocks

88. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace

89. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace

90. page = world.openBillingOverviewPage();
expect(page.getTotalAmount()).toBe('$20');
instance
pricing-get.json
product-usage-get.json
prospective-prices-post.json

91. world.changeStateTo('all-the-products');
all-the-products
pricing-get.json
product-usage-get.json
prospective-prices-post.json
states
page = world.openBillingOverviewPage();
expect(page.getTotalAmount()).toBe('$750');

92. Things to look out for

94. JD Hancock

95. Mocks need to be
up to date and accurate!

103. JSON schema

104. http://json-schema.org

105. {
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"required": [
"hostname",
"currentBillingPeriod", "nextBillingPeriod",
"activeProducts", "deactivatedProducts"
],
"properties": {
"hostname": {
"type": "string"
},

106. {
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"required": [
"hostname",
"currentBillingPeriod", "nextBillingPeriod",
"activeProducts", "deactivatedProducts"
],
"properties": {
"hostname": {
"type": "string"
},

107. {
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"required": [
"hostname",
"currentBillingPeriod", "nextBillingPeriod",
"activeProducts", "deactivatedProducts"
],
"properties": {
"hostname": {
"type": "string"
},

108. {
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"required": [
"hostname",
"currentBillingPeriod", "nextBillingPeriod",
"activeProducts", "deactivatedProducts"
],
"properties": {
"hostname": {
"type": "string"
},

109. "properties": {
"hostname": {
"type": "string"
},
"currentBillingPeriod": {
"$ref": "#/definitions/billingPeriod"
},
"nextBillingPeriod": {
"$ref": "#/definitions/billingPeriod"
},
"activeProducts": {
"type": "array",

110. "properties": {
"hostname": {
"type": "string"
},
"currentBillingPeriod": {
"$ref": "#/definitions/billingPeriod"
},
"nextBillingPeriod": {
"$ref": "#/definitions/billingPeriod"
},
"activeProducts": {
"type": "array",

111. "activeProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
},
"deactivatedProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
}

112. "activeProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
},
"deactivatedProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
}

113. "activeProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
},
"deactivatedProducts": {
"type": "array",
"items": {
"$ref": "#/definitions/product"
}
}

114. },
"definitions": {
"billingPeriod": {
"type": "object",
"required": [
"renewalFrequency", "startDate", "endDate"
],
"properties": {
"renewalFrequency": {
"type": "string"
},
"startDate": {

115. },
"definitions": {
"billingPeriod": {
"type": "object",
"required": [
"renewalFrequency", "startDate", "endDate"
],
"properties": {
"renewalFrequency": {
"type": "string"
},
"startDate": {

116. },
"definitions": {
"billingPeriod": {
"type": "object",
"required": [
"renewalFrequency", "startDate", "endDate"
],
"properties": {
"renewalFrequency": {
"type": "string"
},
"startDate": {

117. },
"definitions": {
"billingPeriod": {
"type": "object",
"required": [
"renewalFrequency", "startDate", "endDate"
],
"properties": {
"renewalFrequency": {
"type": "string"
},
"startDate": {

118. Schema definition
mock server real server

119. Schema definition
mock server real server

120. Schema definition
mock server real server

125. Schema definition

126. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Isolation

127. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Faster dev loop

128. • Big cool statistic
• 2,56
9
• Add-Ons in Marketplace
Better testing

129. Thank you!
PEGGY • SENIOR DEVELOPER • ATLASSIAN • @PYKO