legacy: a retrospective - open west 2016

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

LegacyA Retrospective

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


@jessicamauerhan

2

Senior Test Engineer

Grovo Learning, Inc

[email protected]

jmauerhan.wordpress.com


What is a Retrospectiv

e?

★ What worked well?★ What didn't work

well?★ What would we do

differently next time?

3


★ Content Production★ Learning

Management System

★ E-Commerce★ Business to Business

(B2B)

Project Summary

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LMS + E-Commerce


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

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

Features★ Avoid Downtime

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

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Disclaimer!

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Maintaining and Iterating on Legacy Code is usually

faster, easier and cheaper than a full rewrite


How Did We Do It?

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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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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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Automated Testing

★Unit Tests: Foundation of Test Suite

★Legacy Code = Not Unit Testable

★Solution: Behavior Tests

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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


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


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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Writing Features for Existing CodeWrite FeatureRun Test

Test Passes - Double CheckTest Fails

Described Feature WrongMistake in Test CodeFeature is Broken

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

petty arguments★Just pick one!

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Quality Rules

★Keep New Code from becoming Legacy Code

★Be Specific★Feedback needs to be

immediate - How?

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Quality Enforcement

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

★Quality Checks Run Locally★Bypass in emergency

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Code Review

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

○ Readability○ Business Logic○ Security & Performance

Problems

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Continuing Education

★ Conferences, User Groups, Community

★Weekly Training & Teaching Sessions In-Office

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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

@jessicamauerhan | #OpenWest | https://joind.in/talk/091b9 23


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


Restful API25


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/


60%eBay nearly 60 percent

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90%Expedia a whopping 90 percent

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Make Your API a First

Class Citizen 29


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


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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Technical Goals

Happy Developers!

★Maintainable Code: Check

★Quality Code: Check

★Documentation: Check

★Rapid Development: Oh Yeah

★Easy Deployment: So Easy!

★Zero Regressions: Close Enough!

32


LegacyA Retrospective

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

legacy: a retrospective - open west 2016

Software