legacy: a retrospective - open west 2016

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

LegacyA Retrospective

@jessicamauerhan | #OpenWest| https://joind.in/talk/091b9

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

@jessicamauerhan

2

Senior Test Engineer

Grovo Learning, Inc

jessicamauerhan@gmail.com

jmauerhan.wordpress.com

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

What is a Retrospectiv

e?

★ What worked well?★ What didn't work

well?★ What would we do

differently next time?

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

★ Content Production★ Learning

Management System

★ E-Commerce★ Business to Business

(B2B)

Project Summary

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LMS + E-Commerce

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Problematic History😠 Broken Admin Panel😠 No Documentation of Basic Processes😠 Frontend Site Worked, Progress Stalled😠 Complex Logic not Documented

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Business Goals★ Add Missing Admin Panel Functionality★ Add New Features Without Breaking Existing

Features★ Avoid Downtime

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Technical Goals★ Maintainable Code★ Quality Code★ Documentation★ Rapid Development★ Easy Deployment★ Zero Regressions Per Release

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Disclaimer!

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Maintaining and Iterating on Legacy Code is usually

faster, easier and cheaper than a full rewrite

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

How Did We Do It?

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Version Control

★Easily compare changes★Revert breaking changes to

stable point★Allows developers to work

on multiple tasks concurrently without confusion

★Works best with short-lived branches, and small changesets

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Continuous Integration

& Deployment

★CI: Quickly merge changes into master upon passing tests

★CD: Automatically deploy changes to master upon merge

★Encourages small changesets and rapid development

★Tests are your gatekeeper

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Automated Testing

★Unit Tests: Foundation of Test Suite

★Legacy Code = Not Unit Testable

★Solution: Behavior Tests

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Testing Pyramid

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MaintenanceCoverageFragility DurationCost Number of Tests

Unit Tests

Behavior Tests

System Tests(performance)

GUITests

Unit

Behavior

System

GUI

Manual QA

Testing Ice Cream Cone

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The Vicious Cycle of the Testing Ice Cream Cone

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Unit

Behavior

System

GUI

Manual QA

Non Testable

Code

More Expensive

Tests

Developers Don't

Run Tests

More Bugs

Developers Don't

Write Unit Tests

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Automated Testing

★Unit Tests: Foundation of Test Suite

★Legacy Code = Not Unit Testable

★Short-Term Solution: Behavior Tests

★Long-Term Solution: Write Unit Testable Code & Unit Tests

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Writing Features for Existing CodeWrite FeatureRun Test

Test Passes - Double CheckTest Fails

Described Feature WrongMistake in Test CodeFeature is Broken

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Style Guide★Reduces clutter in diffs★Reduces head-butting &

petty arguments★Just pick one!

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Quality Rules

★Keep New Code from becoming Legacy Code

★Be Specific★Feedback needs to be

immediate - How?

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Quality Enforcement

★Automate All The Things! (Add it to your CI)

★Quality Checks Run Locally★Bypass in emergency

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Code Review

★Always Be Code-Reviewing!★Small PRs★Look for:

○ Readability○ Business Logic○ Security & Performance

Problems

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Continuing Education

★ Conferences, User Groups, Community

★Weekly Training & Teaching Sessions In-Office

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Third Party Tools &

Libraries

★Don't Write Code That Doesn't Contain Business Logic

★Cheaper to Research Third-Party Tools vs. Write It Yourself

○ Does it suit our needs?○ Is it maintained?○ Is it tested?○ Can we contribute?

★Contribute Back!22

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Restful API

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★Client-Facing and Internal Use

★Iterate Front-End Changes to Introduce Unit-Testable Code

★Behavior Tests Covered Front-End Changes

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Restful API25

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

50%Salesforce reportedly generates 50 percent of its revenues through APIs

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https://techcrunch.com/2016/05/21/the-rise-of-apis/

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

60%eBay nearly 60 percent

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https://techcrunch.com/2016/05/21/the-rise-of-apis/

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

90%Expedia a whopping 90 percent

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https://techcrunch.com/2016/05/21/the-rise-of-apis/

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Make Your API a First

Class Citizen 29

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

What Worked?

❖ Version Control

❖ Automated Testing

❖ Style Guide

❖ Code Quality & Enforcement

❖ Code Review

❖ Education

❖ Use of Third Party Tools & Libraries

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What Didn't Work?

❖ Continuous Integration & Deployment

❖ Automated Testing

❖ Neglected Our API

❖ Third Party Tools

➢ Didn't Research Enough

➢ Didn't Contribute Back

➢ Didn't Update

What We Would Do...

❖ Focus on the API First

❖ Microservices

❖ Focus on Unit Testing

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Current Project Status

It's stable!

★New Admin was launched after about 9 months

★Had a few bugs, took about 3 more months to be stable

★Next 2 years: ~0 regressions

★Very limited downtime

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

Technical Goals

Happy Developers!

★Maintainable Code: Check

★Quality Code: Check

★Documentation: Check

★Rapid Development: Oh Yeah

★Easy Deployment: So Easy!

★Zero Regressions: Close Enough!

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@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9

LegacyA Retrospective

@jessicamauerhan | #OpenWest| https://joind.in/talk/091b9