Tests for the Shunting Yard algorithm with parentheses

ShuntingYardTests.scala

package io.jacobappleton.compilers.regex

import org.scalatest.FlatSpec
import scala.language.postfixOps

class ShuntingYardTests extends FlatSpec {
  it should "when given the Regex a.b|c.d the output should be ab.cd.|" in {
      val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
      assert(parser.toPostfix("a.b|c.d") == "ab.cd.|")
  }

  it should "when given the Regex a.(b|c).d the output should be abc|.d." in {
    val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
    assert(parser.toPostfix("a.(b|c).d") == "abc|.d.")
  }

  it should "when given the regex a.b*.c the output should be ab.*c." in {
    val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
    assert(parser.toPostfix("a.b*.c") == "ab*.c.")
  }

  it should "when given the regex a.b**|c the output should be ab**.c|" in {
    val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
    assert(parser.toPostfix("a.b**|c") == "ab**.c|")
  }

  it should "when given the regex a.b.c.d|e the output should be ab.c.d.e|" in {
    val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
    assert(parser.toPostfix("a.b.c.d|e") == "ab.c.d.e|")
  }

  it should "when given the regex j.a(c|o).b the output should be ja.co|.b." in {
    val parser = new ShuntingYard(Map('|' -> 0, '.' -> 1, '*' -> 2))
    assert(parser.toPostfix("j.a.(c|o).b") == "ja.co|.b.")
  }
}