scala-tutorials

This is the main repo for all the sample code used in the scala tutorials.

Pre-requisites

Suggested JDK version : JDK 17

Compiling and Running Tests

This repo uses a multi-module build with many sub modules. To compile the entire module, you may use the command sbt compile. However, this loads all the modules and compiles all of them, which might take some time. If you are interested in only a particular module, you can compile it by starting sbt shell and using the command <sub-module-name>/compile. Similarly, you can run the tests per module as <module-name>/test.

Here are some of the useful commands that can be used within tbe sbt shell

SBT Command	Description	Example
project <sub-module-name>	Switch to a particular module. After this, the command compile, test etc runs only on that module	project scala_core
<sub-module-name>/compile	Compile only the provided module	scala_core/compile
projects	Lists all the sub modules
<sub-module-name>/run	Run the main class within the sub-module	scala_core/run

Note: The project name may not be same as directory name. Instead, it is the lay val variable used to define each module

Test Naming Standards

In this repository, we have classified the tests in 4 categories.

Category	Description
Unit Tests	Smallest unit of testing, that are not dependent on external tools or services
Integration Tests	IntegrationTests means those tests that use some automatic setup within our environment like in-memory Mongo, h2 database etc which don't need explicit setup
Live Tests	Tests that depends on some external services (like httpbin.org, or some internet-based links) or require a running component (eg: starting a Spring Boot application)
Manual Tests	The tests where we need to set up an environment explicitly(for e.g. docker), without which the tests can't be run

Here is a table describing about the different categories of tests and how they can be executed in this project. Note that these commands are defined at the root level of the project and hence are accessible only from the root project(not directly within each submodule).

Category	Sbt command	Test class location	Test class name format
Unit Tests	sbt ci	src/test/scala or src/test/scala-2	No particular format restriction, but as a standard, filename ends with Test
Integration Test (Only)	sbt integrationTests	src/it/scala or src/it/scala-2	No format restriction, but as a standard, filename ends with IntegrationTest
Unit & Integration Test	sbt ciFull	src/it/scala or src/it/scala-2	No format restriction, but as a standard, filename ends with IntegrationTest. These exclude manual and live tests
Live Test	sbt liveTests	src/it/scala or src/it/scala-2	Test class name must end with LiveTest
Manual Test	sbt manualTests	src/it/scala or src/it/scala-2	Test class name must end with ManualTest

Code formatting

Before creating a PR, run sbt scalafmtAll to automatically format the entire codebase. To check if there are any formatting issues(without fixing them), you may run sbt scalafmtCheckAll