Initialize a directory with a basic Mill build configuration, using the latest available version of Mill

millinit

#!/bin/bash
#
# millinit - fetch mill and initialize a project in a directory
#
# This script will query GitHub to find the newest available version of Mill. It
# will download it and initialize a directory with a basic build configuration.
#
# Usage: millinit <directory>
set -o errexit

root="$1"
[[ -z $root ]] && echo -e "Please specify the directory into which you would like to initialize the project.\nUsage:'millinit <directory>'" >&2 && exit 1

mkdir -p "$root"

# Download mill wrapper script
latest_tag=$(curl -sS https://api.github.com/repos/com-lihaoyi/mill/releases/latest | jq -r '.tag_name')
echo "$latest_tag" > "$root/.mill-version"
curl -sS -L "https://github.com/com-lihaoyi/mill/releases/download/$latest_tag/$latest_tag" > "$root/mill"
chmod +x "$root/mill"

# Setup sample project files
cat << 'EOF' > "$root/build.sc"
import mill._, scalalib._, scalafmt._

object app extends ScalaModule with ScalafmtModule {

  def scalaVersion = "3.0.0-RC1"

  object test extends Tests {
    def testFrameworks = Seq("utest.runner.Framework")
    def ivyDeps = Agg(
      ivy"com.lihaoyi::utest::0.7.7"
    )
  }

}
EOF

mkdir -p "$root/app/src"
cat << 'EOF' > "$root/app/src/main.scala"
@main def run() = println("hello, world")
EOF

mkdir -p "$root/app/test/src"
cat << 'EOF' > "$root/app/test/src/Test.scala"
import utest._

object Test extends TestSuite {

  val tests = Tests {
    test("a test") {
      assert(1+1==2)
    }
  }

}
EOF

# Done
echo -e "\e[0;32mSuccess!\e[0m" >&2
echo "The directory '$root' has been initialized with a new Mill build configuration." >&2
echo "The build is configured in the file 'build.sc'. Consult Mill's documentation online at https://com-lihaoyi.github.io/mill/" >&2
echo "It is safe to ignore Mill's output directory 'out':" >&2
echo "  echo out/ >> .gitignore" >&2
echo "The project has been initialized with a couple of default tasks, for example:" >&2
echo "- to run the example application" >&2
echo "    ./mill app" >&2
echo "- to run some unit tests" >&2
echo "    ./mill app.test" >&2