Consider splitting approvaltests module into several targeted ones

[vlsi]

Currently, com.approvaltests:approvaltests:18.5.0 has a lot of "optional" dependencies.
However, in practice, it makes it hard to use the library.

For instance, I wanted to try json approvals, so I tried JsonApprovals.verifyJson("test"), and the test failed in runtime with

com/google/gson/JsonSyntaxException
java.lang.NoClassDefFoundError: com/google/gson/JsonSyntaxException
	at org.approvaltests.JsonApprovals.verifyJson(JsonApprovals.java:20)
	at org.approvaltests.JsonApprovals.verifyJson(JsonApprovals.java:16)

Of course, I'm a programmer, and I know NoClassDefFoundError means the class is missing in runtime, because, well, my app does not really use Gson.

If Approvals wants Gson, fine, however, I would suggest adding a regular (non-optional) dependency.

So if you split modules like

approvaltests-core
approvaltests-json-gson: depends on approvaltests-core, and gson
approvaltests-json-jackson: depends on approvaltests-core, and jackson

approvaltests: depends on approvaltests-core, approvaltests-json-* dependencies for backward compatibility

Then the users would be able to pull just the libraries they need (e.g. approvaltests-json-jackson), and they would get all the needed (e.g. jackson) dependencies automatically.

[LarsEckart]

hello and thank you for your feedback. Just acknowledging that I saw this new issue and that we'll take a look at it next time we meet.