sbt-scrooge

Sbt-scrooge is an sbt plugin that adds a mixin for doing thrift code auto-generation during your compile phase. Just mix in CompileThriftScrooge into your project, and by default, all thrift files matching src/thrift/*.thrift will be used to auto-generate scala sources, written to target/gen-scala.

Building

To build, use sbt:

$ sbt package-dist

How it works

The plugin injects itself into your compile phase.

It fetches scrooge from the public Twitter maven repository and caches it in project/build/target. (You can override this folder -- see below.) It then runs scrooge against your thrift folder, re-generating files only if they've changed. The generated code folder (usually target/gen-scala) is then added to your compile path.

Combining with sbt-thrift

If you still want to use the apache thrift generator in sbt-thrift (for example, to generate java or ruby bindings), use the CompileThriftScroogeMixin mixin instead. It leaves paths undefined so they can be defined once, in your sbt-thrift config.

Configuration

override def scroogeVersion = "1.1.7"

to use a different version of scrooge.
override def scroogeBuildOptions = List("--finagle", "--ostrich")

to change the generated code options. By default, finagle client/server and ostrich service stubs are generated.
override def scroogeDebug = false

to see more debug info (like the scrooge command line)
override def scroogeCacheFolder = ("project" / "build" / "target" / scroogeName) ##

to change the folder that cached versions of scrooge are stored in.
override def thriftSources = (mainSourcePath / "thrift" ##) ** "*.thrift"

to change where thrift files are found.
override def generatedScalaPath = (outputPath / "gen-scala") ##

to change the default destination folder for generated scala files.
override def thriftIncludeFolders: Seq[String] = Nil

to set some default include paths for thrift.

Upgrading from sbt-thrift

The scala bindings are not 100% compatible with the scala bindings that were generated by sbt-thrift. Here are the notable differences:

You need to add "scrooge-runtime" as a dependency:

val scrooge_runtime = "com.twitter" % "scrooge-runtime" % "1.0.3"
The names of the interfaces have changed:
- (service).ServiceIface is now (service).FutureIface
- (service).Service is now (service).FinagledService
- (service).Client is now (service).FinagledClient
- BinaryThriftSerializer is now BinaryThriftStructSerializer[A], like:
  
  val serializer = new BinaryThriftStructSerializer[Beer] { def codec = Beer }

Upgrading from java

If you're switching from java generated code, there are a few other (fairly large) differences:

All container types are scala-native (Seq, Set, Map).
Enums are case objects (but still subclass TEnum).
Class, struct, and enum names are all converted to StudyCaps, so for example ERROR becomes Error.
Method names are all converted to camelCase, so for example GetName becomes getName and set_name becomes setName.
Structs are case classes, so they are immutable and have real, actual constructors (!). Multi-line field-setting struct construction should be converted to a single-line case class constuctor call.
Optional fields are implemented as Option[A].