This is a template for Cookiecutter, a tool that creates projects from project templates. Using this template you can create a working project skeleton for a simple hello world-like Scala project, with some additional bells and whistles, if needed, like:
- sbt to build the project
- scalatest to test the code
- Apache Toree to explore the code interactively in a notebook
- assembly to deploy fat JARs (optional)
- scoverage to create code coverage reports (optional)
- scalariform to format the code (optional)
- json4s to use JSON (optional)
- scala-csv to use CSV (optional)
- scalapb to read/write Protobuf messages (optional)
Most of these are optional and will be added to a newly created project only when provinding a version number other than - for the respective library during project instantiation. The default version numbers are the most recent ones, but are hardwired and not dynamically looked up.
- install cookiecutter, see documentation
- run
cookiecutter https://github.com/deeplook/cookiecutter-scala.git
A minimal version using only default version numbers and no optional libraries looks like this:
$ cookiecutter https://github.com/deeplook/cookiecutter-scala.git
app_name [hello-world]:
app_slug [hello_world]:
app_version [0.1.0]:
package_name [org.cookiecutter.scala.hello_world]:
sbt_version [0.13.15]:
scala_version [2.12.2]:
scalatest_version [3.0.1]:
scoverage_version [1.5.0]: -
json4s_version [3.5.2]: -
scala_csv_version [1.3.4]: -
sbt_scalariform_version [1.6.0]: -
sbt_protoc_version [0.99.8]: -
scalapb_compilerplugin_version [0.6.0]: -
$ tree hello-world/
hello-world/
├── .gitignore
├── .travis
├── README.md
├── build.sbt
│ ├── build.properties
│ └── plugins.sbt
├── notebooks
│ └── {{cookiecutter.app_slug}}.ipynb
└── src
├── main
│ └── scala
│ └── Main.scala
└── test
└── scala
└── MainSpec.scalaA maximal version using only default version numbers, also for all optional libraries, looks like this:
$ cookiecutter https://github.com/deeplook/cookiecutter-scala.git
app_name [hello-world]:
app_slug [hello_world]:
app_version [0.1.0]:
package_name [org.cookiecutter.scala.hello_world]:
sbt_version [0.13.15]:
scala_version [2.12.2]:
scalatest_version [3.0.1]:
scoverage_version [1.5.0]:
json4s_version [3.5.2]:
scala_csv_version [1.3.4]:
sbt_scalariform_version [1.6.0]:
sbt_protoc_version [0.99.8]:
scalapb_compilerplugin_version [0.6.0]:
$ tree hello-world/
hello-world/
├── .gitignore
├── .travis
├── assembly.sbt
├── README.md
├── build.sbt
├── notebooks
│ └── {{cookiecutter.app_slug}}.ipynb
├── project
│ ├── assembly.sbt
│ ├── build.properties
│ ├── plugins.sbt
│ └── scalapb.sbt
└── src
├── main
│ ├── protobuf
│ │ └── person.proto
│ └── scala
│ └── Main.scala
└── test
├── resources
│ ├── README.md
│ └── airport-codes.csv
└── scala
├── MainSpec.scala
├── TestJson.scala
└── TestProtobuf.scalaFor a sample project named hello_world using all optional libraries you can test your newly created project running this sequence of sbt commands (output heavily trimmed):
$ cd hello_world
$ sbt compile
...
[success] Total time: 11 s, completed Jul 4, 2017 10:47:55 AM
$ sbt run
...
[info] Running org.cookiecutter.scala.hello_world.Main
Hello World
[success] Total time: 6 s, completed Jul 4, 2017 10:48:49 AM
$ sbt test
...
[info] Run completed in 555 milliseconds.
[info] Total number of tests run: 5
[info] Suites: completed 3, aborted 0
[info] Tests: succeeded 5, failed 0, canceled 0, ignored 0, pending 2
[info] All tests passed.
[success] Total time: 7 s, completed Jul 4, 2017 10:49:29 AM
$ sbt doc
...
[info] Main Scala API documentation to /[...]/hello-world/target/scala-2.12/api...
model contains 11 documentable templates
[info] Main Scala API documentation successful.
[success] Total time: 4 s, completed Jul 4, 2017 10:50:33 AM
$ sbt clean coverage test
...
[info] [info] Beginning coverage instrumentation
[info] [info] Instrumentation completed [130 statements]
[info] [info] Wrote instrumentation file [/[...]/hello-world/target/scala-2.12/scoverage-data/scoverage.coverage.xml]
[info] [info] Will write measurement data to [/[...]/hello-world/target/scala-2.12/scoverage-data]
...
[info] All tests passed.
[success] Total time: 12 s, completed Jul 4, 2017 10:52:00 AM
$ sbt coverageReport
...
[info] Generating scoverage reports...
[info] Written Cobertura report [/[...]/hello-world/target/scala-2.12/coverage-report/cobertura.xml]
[info] Written XML coverage report [/[...]/hello-world/target/scala-2.12/scoverage-report/scoverage.xml]
[info] Written HTML coverage report [/[...]/hello-world/target/scala-2.12/scoverage-report/index.html]
[info] Statement coverage.: 30.00%
[info] Branch coverage....: 62.50%
[info] Coverage reports completed
[info] All done. Coverage was [30.00%]
[success] Total time: 2 s, completed Jul 4, 2017 10:53:15 AM
$ sbt assembly
...
[info] Assembly up to date: /[...]/hello-world/target/scala-2.12/hello_world-assembly-0.1.0.jar
[success] Total time: 3 s, completed Jul 12, 2017 9:03:10 PM
$ java -cp /[...]/hello-world/target/scala-2.12/hello_world-assembly-0.1.0.jar org.cookiecutter.scala.hello_world.Main
Hello World$ sbt console
...
// main functionality
scala> import org.cookiecutter.scala.hello.Main
import org.cookiecutter.scala.hello.Main
scala> Main.main(Array())
Hello World
// protobuf
scala> import person.Person
import person.Person
scala> val p = Person(name=Some(“Joe”))
p: person.Person =
name: “Joe”
// json
scala> import org.json4s._
import org.json4s._
scala> import org.json4s.jackson.JsonMethods._
import org.json4s.jackson.JsonMethods._
scala> val obj = parse(""" { "numbers" : [1, 2, 3, 4] } """)
obj: org.json4s.JValue = JObject(List((numbers,JArray(List(JInt(1), JInt(2), JInt(3), JInt(4))))))
// csv
scala> import com.github.tototoshi.csv.CSVReader
com.github.tototoshi.csv.CSVReader
scala> import java.io.File
import java.io.File
scala> val reader = CSVReader.open(new File("src/test/resources/airport-codes.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@4b2809a1
scala> reader.allWithHeaders()(0)
res2: Map[String,String] = Map(coordinates -> -74.93360138, 40.07080078, name -> Total Rf Heliport, iso_country -> US, iso_region -> US-PA, continent -> NA, local_code -> 00A, ident -> 00A, iata_code -> "", gps_code -> 00A, elevation_ft -> 11, type -> heliport, municipality -> Bensalem)
// TODO: add a corresponding CSV section to the tutorial notebookThis should give you a fully functional SBT-based Scala project, with some additional useful goodies if you like, that you can further modify according to your needs.