ScalaMake

Sometimes all you need is something to process filesystem constraints and script Scala, Java, or platform shell commands based on the dependencies in your filesystem. Sometimes all you need is a cross-platform thing like "Make". Sometimes all you need is ScalaMake.

Internally, I use ScalaMake to script separate builds (that may run using Maven or SBT) into a cohesive whole.

"OK already, enough talk: show me the code!" :-)

What ScalaMake code looks like

The complete ScalaMake specification is defined using "Specs" and it's in the zipfile, but here's a taste:

You can use ScalaMake in any of the following ways:

• Use the scalaMake keyword in any Scala code
• Create a ScalaMakefile object that you can run like any regular Scala application, or
• Build a ScalaMake makefile as a Scala script and run it directly using the "scalamake" shell script (without compiling it).

These examples come from the ScalaMake specification/tests, and use the first option:

"Runs a rule and a dependency" in {
  var rulesProcessed : List[String] = Nil
  scalaMake {
    "ALL" dependsOn "dependantRule" buildWith { 
      // In real code you would actually build something here, 
      // but since this is a test, we'll just note that we were called.
      rulesProcessed = rulesProcessed ::: List("ALL")
    }
  
    "dependantRule" buildWith { 
      rulesProcessed = rulesProcessed ::: List("dependantRule")
    }
  }
  val expectedRuleOrder = "dependantRule" :: "ALL" :: Nil
  expectedRuleOrder.equals(rulesProcessed) mustBe true
}

You can use Ant-style recursive directory dependencies:

"Build target if any (path/to/**/*.ext) is newer" in {
  !"touch target.txt"
  makeTestFiles("testSrc", "txt")  // test files will be newer

  var targetWasBuilt = false
  scalaMake {
    "target.txt" dependsOn "testSrc/**/*.txt" buildWith {
      targetWasBuilt = true
    }
  }

  targetWasBuilt mustBe true
}

"Build (some/path/**) as a dependency" in {
  // This was done above, so we won't redo
  //makeTestFiles("testSrc", "txt")  // test files will be newer
  var built = false

  scalaMake {
    "ALL" dependsOn ("testSrc/**", "FOO")
  
    "FOO" buildWith {
      // noop
    }
  
    "testSrc/**" buildWith {
      built = true;
    }
  }

  built mustBe true
}

That's enough for now. If you like this, just download the .zip and get started. Or pull the whole repo, build it using SBT, and contribute!

--Dave Orme