ShouldBe | Beautiful object graph assertions for C | Assertion library

The best practice is to place application.conf into src/main/resources/ for regular use and into src/test/resources/ for testing. You'll have 2 conf files with different values in test. If you don't need to change config for test you can simply keep one conf file in main.

You don't have to override the file explicitly with -Dconfig.resource or -Dconfig.file for your tests because loading resources from class path will work as you expect out of the box and your test config will be used. -D option is mostly used at runtime to provide external configuration or in some complex build scenarios.

If you use -Dconfig.resource or -Dconfig.file pay attention to the path. config.resource is just a filename, i.e. application.conf which will be loaded as resource while config.file is an absolute or relative file path.

If you are making a library you can get fancy with reference.conf file having default values and application.conf overriding them. This could also work in your scenario but would be more confusing because that's not the purpose or reference file.

For the purposes of testing just use 2 application.conf files.

Additionally, here are some options to override config at runtime:

Overriding multiple config values in Typesafe config when using an uberjar to deploy.

Overriding configuration with environment variables in typesafe config

Scala environment ${USER} in application.conf

More info here: https://github.com/lightbend/config#standard-behavior

A simple approach:

I changed hackage regex-pcre-builtin to light-pcre. And it works !

I haved to encode my strings into ut8 bytestring then add utf8 compile-time flag

Yes, this is a proper way to test an application because modules don't depend on each other and are bound via configuration. Also, instead of adding one more extension method for Application, you can introduce the following helper function just for testing:

The problem is that code like

So the fix was to not rely on $ to match the newline but to do it manually.

I use now: @"([^\r\n]+\r?\n?)" with RegexOptions.SingleLine (not sure if necessary) and it works fine for my use-cases.

JaCoCo analyzes .class files, not source files. The Scala compiler may produce multiple .class files from a single source file. Your SayHello.scala class most likely contains a companion object. An object is always compiled to a class of the same name with $ at the end, which implements the companion object singleton at the bytecode level. If you go to your target/classes directory, you'll most likely see those two files there - SayHello.class and SayHello$.class.

Two records in the JaCoCo report correspond to those two class files. The dot at the end instead of a $ is most likely a jacoco report rendering issue.

To skip the companion object class from analyzing, just add it to your exclusion list:

Assuming you're getting the error:

I think this is all you need.