ScalaTest in sbt: is there a way to run a single test without tags?

Question

I know that a single test can be ran by running, in sbt,

testOnly *class -- -n Tag

Is there a way of telling sbt/scalatest to run a single

Answer 1

Here's the Scalatest page on using the runner and the extended discussion on the -t and -z options.

This post shows what commands work for a test file that uses FunSpec.

Here's the test file:

package com.github.mrpowers.scalatest.example

import org.scalatest.FunSpec

class CardiBSpec extends FunSpec {

  describe("realName") {

    it("returns her birth name") {
      assert(CardiB.realName() === "Belcalis Almanzar")
    }

  }

  describe("iLike") {

    it("works with a single argument") {
      assert(CardiB.iLike("dollars") === "I like dollars")
    }

    it("works with multiple arguments") {
      assert(CardiB.iLike("dollars", "diamonds") === "I like dollars, diamonds")
    }

    it("throws an error if an integer argument is supplied") {
      assertThrows[java.lang.IllegalArgumentException]{
        CardiB.iLike()
      }
    }

    it("does not compile with integer arguments") {
      assertDoesNotCompile("""CardiB.iLike(1, 2, 3)""")
    }

  }

}

This command runs the four tests in the iLike describe block (from the SBT command line):

testOnly *CardiBSpec -- -z iLike

You can also use quotation marks, so this will also work:

testOnly *CardiBSpec -- -z "iLike"

This will run a single test:

testOnly *CardiBSpec -- -z "works with multiple arguments"

This will run the two tests that start with "works with":

testOnly *CardiBSpec -- -z "works with"

I can't get the -t option to run any tests in the CardiBSpec file. This command doesn't run any tests:

testOnly *CardiBSpec -- -t "works with multiple arguments"

Looks like the -t option works when tests aren't nested in describe blocks. Let's take a look at another test file:

class CalculatorSpec extends FunSpec {
  it("adds two numbers") {
    assert(Calculator.addNumbers(3, 4) === 7)
  }
}

-t can be used to run the single test:

testOnly *CalculatorSpec -- -t "adds two numbers"

-z can also be used to run the single test:

testOnly *CalculatorSpec -- -z "adds two numbers"

See this repo if you'd like to run these examples. You can find more info on running tests here.