Clone or copy the warbler file and license into your codebase. Does wren have a package manager yet? Is that a thing?
Create a test file and import/use the Test class like so:
import "warbler" for Test
System.print("Testing...")
var test = Test.new("Reality")
test.describe("Everything is sane") {
test.assert(true, true, "booleans work")
}
test.describe("The world is upside down") {
test.assert(true, true)
}
Test output:
Testing Reality.
Describe: Everything is sane
GREAT SUCCESS: booleans work
Describe: The world is upside down
FAIL: true was not false in Reality.