Streamline Integration Testcontainers IBM · tests because… •Tests do not reflect prod...

Streamline Integration Testing with Testcontainers—Andrew GuibertSoftware EngineerIBM

@andrew_guibert

Why do we write automated tests?

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Why do we write automated tests?

To have confidence that our application works the way we want it to.


What type of testing gives us the most confidence?

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Source: If applicable, describe source origin

System/UITesting

Unit Testing

Integration Testing

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Which type of tests contribute more to your confidence in your automated tests?

Unit/Mock tests24%

Integration (i.e. "live server") tests76%

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4/4 Unit Tests Passing

Faucet turns on

Faucet turns off

Drain works

Sink does notoverflow

© 2019 IBM CorporationEclipseCon EU 2019 | © 2019 IBM Corporation

EclipseCon EU 2019 | © 2019 IBM Corporation

EclipseCon EU 2019 | © 2019 IBM Corporation @andrew_guibert

What we have time to do


Source: If applicable, describe source origin

Unit Testing

Integration Testing

Manual testing if I remember and am not swamped

@andrew_guibert

The dilemma of testing

Confidence

Time given© 2019 IBM CorporationEclipseCon EU 2019 | © 2019 IBM Corporation @andrew_guibert


Confidence

Time given

Confidence level in tests

© 2019 IBM CorporationEclipseCon EU 2019 | © 2019 IBM Corporation @andrew_guibert


Confidence

Time given

Confidence level in tests


The Twelve-Factor App


VII. Port Binding

VIII.Concurrency

IX. Disposability

X. Dev-Prod Parity

XI. Logs

XII. Admin Processes

I. Codebase

II. Dependencies

III. Config

IV. Backing Services

V. Build, Release, Run

VI. Stateless Processes

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Dev-Prod Parity


Keep development, staging, and production as similar as possible

Comprised of three common issues:– The time gap– The personnel gap– The tools gap

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“The twelve-factor developer resists the urge to use different backing services between development and production, even when adapters theoretically abstract away any differences in backing services.”


Dev-Prod Parity

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It works on my machine.


Can you spot what’s wrong here?


Testing with databases



Why do we do this?

• Easy to set up

• Faster than the real thing

• Been doing it this way for >10 years

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Containers

• Combines everything needed to run a service into a single unit

• Standard way to manage

• Lightweight and disposable

• Typically configured via env

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What it looks like


Using Testcontainers


• Databases

• Messaging Brokers

• External Services

• Anything in a container

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Taking things a step further


Motivation

Devs lack confidence in their tests because…

• Tests do not reflect prod

• Writing tests takes too long

• Setup is too complex

11

11

10

7

18

9

0 10 20

WRITING TESTS IS TOO COMPLICATED OR TIME …

OUR APP IS TOO BIG/COMPLEX TO TEST

RUNNING THE TESTS WE HAVE TAKES TOO LONG

DEBUGGING A TEST THAT FAILS TAKES TOO LONG

THE TESTS WE HAVE DO NOT ACCURATELY REPRESENT HOW …

SETTING UP OR CONFIGURING TESTS IS TOO COMPLICATED

What factors are limiting the confidence in your automated tests?


1) Easy to set up 2) Works with• Java EE• Jakarta EE• MicroProfile

3) Provide true-to-production tests

MicroShed Testing


MicroShed Testing

Test client JVM Docker network *

App container

App containerApp containerOther container

resources(e.g. DB)

User test code

MicroShed Testing

Testcontainers

docker-java

Convenience libs

(e.g. REST client)controls

* May be on different machine from test client

Test request/responses

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Example Application


Automatically discover, build, and start services


a) Provide container label

b) Locate Dockerfile

c) Use default image

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Wait for app container to be ready


• Defaults to app context root

• Can use MP Health 2.0 readiness check

• Can supply path manually

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Inject REST client


• Can re-use class from app

• Can define own client

• Automatically configured for app container

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Drive requests on running app container


• Real HTTP requests

• Parameters and return values converted with JSON-B

• JWT tokens applied automatically

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Where to learn more


Testcontainers– testcontainers.org– github.com/testcontainers/testcontai

ners-java

MicroShed–microshed.org/microshed-testing/– github.com/MicroShed/microshed-

testing

Demo Used– github.com/aguibert/oc1-demo

Andrew Guibert@andrew_guibert@aguibert

@andrew_guibert

Streamline Integration Testcontainers IBM · tests because… •Tests do not reflect prod...

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