Pretty diffs for case classes.
The library is published for Scala 2.12 and 2.13.
- integrations
- direct usage
- customization
- ignoring
- tagging support
To use with scalatest, add the following dependency:
"com.softwaremill.diffx" %% "diffx-scalatest" % "0.3.8"Then, extend the com.softwaremill.diffx.scalatest.DiffMatcher trait or import com.softwaremill.diffx.scalatest.DiffMatcher._.
After that you will be able to use syntax such as:
left should matchTo(right)Giving you nice error messages:
To use with specs2, add the following dependency:
"com.softwaremill.diffx" %% "diffx-specs2" % "0.3.8"Then, extend the com.softwaremill.diffx.specs2.DiffMatcher trait or import com.softwaremill.diffx.specs2.DiffMatcher._.
After that you will be able to use syntax such as:
left must matchTo(right)Add the following dependency:
"com.softwaremill.diffx" %% "diffx-core" % "0.3.8"Then call:
import com.softwaremill.diffx.Diff
Diff[T].apply(o1, o2)If you'd like to implement custom matching logic for the given type, create an implicit Diff instance for that
type, and make sure it's in scope when any any Diff instances depending on that type are created.
Fields can be excluded from comparision by calling the ignore method on the Diff instance.
Since Diff instances are immutable, the ignore method creates a copy of the instance with modified logic.
You can use this instance explicitly.
If you still would like to use it implicitly, you first need to summon the instance of the Diff typeclass using
the Derived typeclass wrapper: Derived[Diff[Person]]. Thanks to that trick, later you will be able to put your modified
instance of the Diff typeclass into the implicit scope. The whole process looks as follows:
implicit modifiedDiff: Diff[Person] = Derived[Diff[Person]].ignore(_.name)To use with softwaremill-tagging library, add the following dependency:
"com.softwaremill.diffx" %% "diffx-tagging" % "0.3.8"And then extend com.softwaremill.diffx.tagging.DiffTaggingSupport trait or import com.softwaremill.diffx.tagging.DiffTaggingSupport._
Diffx should be able to work with any other tagging library. I decided to create this module in order to check if any future changes won't break this integration.
If you want to use diffx with other tagging library you need to provide a way for creating Diff type class for tagged types:
implicit def taggedDiff[T: Diff, U]: Derived[Diff[T @@ U]] = Derived(Diff[T].contramap[T @@ U](identity))We offer commercial support for diffx and related technologies, as well as development services. Contact us to learn more about our offer!
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