POST/CON 2019 Workshop: Testing, Automated Testing, and Reporting APIs with Postman

Sept 11, 2019
PRESENTED BY
Testing, Automation &
Reporting with Postman
Trent McCann - Engineering Manager, Quality
Danny Dainton - Senior Quality Engineer

Speakers
Danny Dainton
Senior Quality Engineer
Trent McCann
Engineering Manager, Quality

Housekeeping
• Wiﬁ - PostmanWIFI p/POSTCON!
• Washrooms / Beverages
• Facilitators
• Breaks

● Testing Module Part I
● Testing: Practical Exercises
● Break
● Testing Module Part II
● Testing: Practical Exercise
● Break
● Automation
● Reporting
● Workshop Wrap-up
Agenda

Import Collections
1. Navigate to bit.ly/POSTCON2019WORKSHOP
2. Copy the ﬁrst Collection link and open up the Postman app
3. Select the Import button at the top of the app.
4. Select Import From Link tab
5. Paste the URL into the ﬁeld
6. Click Import
7. Repeat for the second link

Assumptions
This session assumes that
attendees:
● Are comfortable making Requests
in Postman
● Possess basic working knowledge
of JavaScript
● Have the Latest Postman Desktop
App Installed for your OS

What the Hell is API Testing?
● People generally think that API testing is a form of software testing
that you need to know about before getting started
● It is testing but in a diﬀerent context
● You are still:
○ Using the same test skills and techniques but applying them
diﬀerently
○ Focused on mitigating risk
○ Providing information about the software under test

Why Write API Tests?
● Determine if the application under test meets expectations for
functionality, reliability, performance, and security
● Ensure consistent high quality as your application grows
● Critical component for automating testing – APIs are the primary
interface to application logic
● Tests at the API layer are less brittle and easier to maintain
● Most stable interface - GUI tests are not suﬃcient to validate all
functional paths of a multi-tier architecture

Scripts
• Postman contains a powerful runtime based on Node.js that allows
you to add dynamic behavior to requests and collections
• Allows you to write test suites, build requests that can contain
dynamic parameters, pass data between requests and more
• You can add JavaScript code to execute during 2 events in the ﬂow:
• Before a request is sent to the server, under the Pre-request Script tab
• After a response is received, as a test script under the Tests tab

Execution Order of Scripts
• A Pre-request Script associated with a request will execute before the request
is sent
• A Test script associated with a request will execute after the request is sent
REQUEST
Pre-request script
REQUEST RESPONSE
REQUEST
test script

Pre-Request Scripts
• Snippets of code associated with a collection request that are executed
before the request is sent
• Example use cases:
• Including the timestamp in the request headers or
• Sending a random alphanumeric string in the URL parameters
• Can be added to a collection, a folder, or a single request within a collection
• Runs prior to each request in the respective collection or folder, allowing for
commonly used code to be executed prior to every request

Pre-Request Script Execution
For every request in a collection, scripts will execute in the following order:
• A pre-request script associated with a collection or folder will run prior to every
request in the respective collection or folder
REQUEST
Pre-request script
REQUEST
FOLDER
Pre-request script
COLLECTION
Pre-request script

Practical
Exercise:
Pre-Request
Scripts

1. Click on the New button
2. Select Request
3. Enter a Request Name
4. Create Collection and enter name
Steps
5. Enter URL https://postman-echo.com/get
and hit Send
6. Click on Gear Icon
7. Click on the Add button
8. Enter a name and click Add
9. Select Environment from Dropdown

10. Select the Pre-request Script tab
11. Type:
pm.environment.set("dateTime", new Date());
12. Select the Params tab
13. Enter “date” for the key
and “{{dateTime}}” for the value.
Steps
14. Hit Send

Test Scripts
● JavaScript code executed after the request is sent, allowing
access to the pm.response object.
● Tests run in a sandboxed environment, which is separate
from the execution environment of the app
● Commonly used snippets are listed next to the editor and are
a great way to build test cases
○ Select the snippet you want to add and the appropriate
code will populate in the test editor

For every request in a collection, scripts will execute in the following order:
• A test script associated with a collection or folder will run after every request in the
respective collection or folder
RESPONSE
COLLECTION
test script
FOLDER
test script
REQUEST
test script
Test Script Execution

Practical
Exercise:
Test Scripts

1. Select the Tests tab
2. Select Status Code: Code is 200 Snippet
3. Select Response Time is less than
200ms Snippet
4. Edit 200ms to 100ms
Steps
6. Select Test Results tab
5. Hit Send

7. Highlight and Cut the Tests from Request
8. Save Changes to the Request
9. Edit the Collection
10. Select Tests tab
Steps
12. Hit Send
11. Paste Tests and click Update

Level Up Your Testing In
Postman

What do we mean by
advanced techniques?

Dynamic Variables
● Postman has dynamic variables that can be used in requests
● Values are randomly generated during the request/collection run
● Established variables {{$randomInt}}, {{$timestamp}} and
{{$guid}} have been included for many versions
● Random fake data can be generated using a subset of the FakerJS
functions
● Can used in the URL, Headers, Request Body and also within Mock
Server Examples

Chai Assertions
• Using the popular and well known Chai.js library
• Chai provides natural language assertions in an
expressive and readable style
• Chained together by a series of getters
• be / been / is / and / has / have / not
• Works with the pm.expect() function
• The assertion always starts with the .to getter

Built-In Libraries
• Lodash: JS utility library
• Moment: Parse, validate, manipulate, and display dates and
times in JavaScript.
• Cheerio: A fast, lean implementation of the core jQuery API
• Ajv: JSON schema validator.
• CryptoJS: Standard and secure cryptographic algorithms.
• xml2Json: Simple XML to JSON Convertor.

Postman Console
• Debugging scripts can be written under either
the Pre-request Script tab or the Tests tab,
with helpful messages logged in the Postman
Console.
• The Postman Console is analogous to a
browser’s version of Developer console,
except that it’s tuned for API development.
• If an API or API test is not behaving as you
expect, this would be the place where you will
go to deep dive while debugging the same.
● The Postman Console can be compared to a browser’s
Developer console, but tuned for API development
● When debug scripts are written under the Pre-request Script
or Test tabs, helpful messages will be logged in the Postman
Console
● If an API or API test is not behaving as expected, the console
will assist with debugging

What Does it Do?
• Logs the request that was sent, including all the underlying
request headers, status code etc.
• Logs the exact response sent by the server
• Displays what proxy and certiﬁcates were used for the
request
• Shows error logs from Test or Pre-request Scripts
• Allows the console.log() statement to be used from inside
sandbox

Console.log();
Your New
Best Friend
• JS method used to write
messages to the debug
console
• Can be used for debugging
your test scripts and
capturing key information
from the test runs

Practical
Exercise:
Advanced
Techniques

Collection Runner
• Collections are groups of requests that can be run together as a series of requests, against a corresponding
environment.
• Running a collection is useful when you want to automate API testing. When you run a collection, you send all
requests in your collection one after another.
• When you use scripts, you can build integration test suites, pass data between API requests, and build workﬂows
that mirror your actual use case of APIs.
● Collections are groups of requests that can be run together as a
series, against a corresponding environment
● Enables automation of API test collections
● When a collection is run, all requests in the collection will be sent
one after another
● Using scripts allows you to:
○ Build integration test suites
○ Pass data between API requests
○ Build workﬂows that mirror API use cases

Practical
Exercise:
Collection
Runner

Steps
1. Navigate to the Collections tab
2. Click on the Navigation arrow and hit Run
3. Click on the Run “collection name” button
4. Run Results
5. Click on request name

What is Newman?
● A globally installed NPM package
● A Collection Runner for Postman that runs directly from the
command line
● Easily integrates with continuous integration servers and build
systems
● Maintains feature parity with the Postman App
● Allows Collections to be run the way they are executed in the
Postman app collection runner
● Built as a library - can be extended and used ﬂexibly
● Collection run reports can be generated using diﬀerent
custom reporters

POST/CON 2019 Workshop: Testing, Automated Testing, and Reporting APIs with Postman

CI/CD • Newman can run on
popular CI/CD frameworks
such as Jenkins, Travis,
CircleCI and even Azure
(via VSTS).
• Provides a streamlined
way to run Newman in a
Docker container without
operating system
dependencies or
environment setup

Reporting: “And that’s
the way it is.”

Why Do We Create Reports?
Reports are generally created to communicate information to some
person, The type of report and the details about what it should contain,
will diﬀer from person to person.
Things to consider when creating reports:
● The report's intended audience
● The report's purpose
● The type of information to be communicated

Standard Newman Reporters
CLI
This is the default reporter that comes with Newman and is the standard
output that you will see. There are a number of different configurable
options/cli arguments available to present that out in specific ways.
JUNIT
This reporter will create an XML file containing the all high level test
result data, this can be picked by CI tools like Jenkins to display a
graphical representation of the overall test coverage

Reporters Created By The
Postman Community

A new take on a modern classic...
HTMLEXTRA Report
bit.ly/newmanhtmlextra
Postman HTML
Report
bit.ly/newmanhtml

Review
● Testing within Postman can be an effective way to give you confidence that
your API endpoints are returning the correct information without having to
manually confirm this on each request
● Postman is packed full of different helpers, libraries and utilities that can
enable you to create more complex test suites
● Automating a Collection within the App is super simple using the Built In
Runner
● You can use Newman to run your Collections from either the Command
Line or easily integrate into your CI systems

Recommended Resources
● Postman Community - https://community.getpostman.com
● Learning Centre - https://learning.getpostman.com
● GitHub Repo - https://github.com/postmanlabs/postman-app-support
● Support Portal - https://support.getpostman.com/hc
Trent
ca/linkedin.com/in/trentmccann
@Postman_Trent
Danny
uk/linkedin.com/in/dannydainton
@DannyDainton
Keep In Touch!

Workshop Resources
bit.ly/POSTCON2019WORKSHOP

POST/CON 2019 Workshop: Testing, Automated Testing, and Reporting APIs with Postman

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POST/CON 2019 Workshop: Testing, Automated Testing, and Reporting APIs with Postman