the key to move really fast – lightning talk | niclas nilsson | ltg-43/dtg-7
TRANSCRIPT
The key to move really fast
Niclas Nilsson
Jon-Erling Dahl
Coaching and consulting
Automates your paperwork
The new reality
Release more often
Solution:
Test automation
Automation of System Tests
"We have unit tests with good coverage."
Acceptance Tests > Unit Tests
2 unit tests
0 acceptance tests
We need automated acceptance tests
BDDBehaviour Driven Development
ATDDAcceptance-Test Driven
Development
Communicate throughstories
ATM exampleFeature: Cash withdrawal In order to get money when the bank is closed As an Account Holder I want to withdraw cash from an ATM
Scenario: Account has sufficient funds Given the account balance is 100 And the card is valid And the machine contains enough money When the account holder requests 20 Then the ATM should dispense 20
Not just happy casesScenario: Account has insufficient funds Given the account balance is 10 And the card is valid And the machine contains enough money When the account holder requests 20 Then the ATM should not dispense any money And the ATM should say there are insufficient funds And the account balance should be 10 And the card should be returned Scenario: Card has been disabled Given the card is disabled When the account holder requests 20 Then the ATM should retain the card
StoriesAll in plain textWorks well on paperIf only we could execute it...
Cucumber
http://cukes.info
“Cucumber is a tool for runningautomated tests written in plain
language”
Features in plain textFeature: Cash withdrawal In order to get money when the bank is closed As an Account Holder I want to withdraw cash from an ATM
Scenario: Account has sufficient funds Given the account balance is 100 And the card is valid And the machine contains enough money When the account holder requests 20 Then the ATM should dispense 20
Not just happy casesScenario: Account has insufficient funds Given the account balance is 10 And the card is valid And the machine contains enough money When the account holder requests 20 Then the ATM should not dispense any money And the ATM should say there are insufficient funds And the account balance should be 10 And the card should be returned Scenario: Card has been disabled Given the card is disabled When the account holder requests 20 Then the ATM should retain the card
Features in plain textFeature: Cash withdrawal In order to get money when the bank is closed As an Account Holder I want to withdraw cash from an ATM
Scenario: Account has sufficient funds Given the account balance is 100 And the card is valid And the machine contains enough money When the account holder requests 20 Then the ATM should dispense 20
Stepsin any programming language
CucumberSpecflowBehat...and many more
Unit testsCovers smaller units/componentsFast execution timesVery technicalGood for complex algorithmsGood for reusable components
Acceptance testsCovers slices of the complete systemSlower execution timesIntentionalGood for the complete systemGood for avoiding complex/subtle integration bugsProvides a holistic safety net
Test through the browser
Hit the database
Only mock external systems
"But that's so slow..."
True.But the value is much higher.
"But it's quite hard..."
At first.But it gets quite easy after the initial
efforts.
"But it takes more time..."
True. At first.But after a short while, you get
much faster.
And by the way:
You can actually have thecookie and eat it too.
How to have the cookie and eat it too:The feature specs should always hold.But you can have multiple sets of step definitions- Full scale, including UI and DB- Lighter and faster, no UI, no DBNote: The same feature specs - different step impls!
Unit tests cannot replace acceptance tests
but...
Acceptance tests can replace unit tests
Most good systems have both
Avoid record/replayOften very brittle
Craft them well.
And remember...
Acceptance Tests > Unit Tests
We help you get started