actually add LitTest file

core/src/test/scala/org/bykn/bosatsu/LitTest.scala

@@ -0,0 +1,56 @@
+package org.bykn.bosatsu
+
+import org.scalacheck.Gen
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks.{ forAll, PropertyCheckConfiguration }
+import org.scalacheck.Arbitrary
+import org.typelevel.paiges.Document
+
+class LitTest extends AnyFunSuite {
+  def config: PropertyCheckConfiguration =
+    PropertyCheckConfiguration(minSuccessful = if (Platform.isScalaJvm) 1000 else 100)
+
+  val genLit: Gen[Lit] =
+    Gen.oneOf(
+      Gen.choose(-10000, 10000).map(Lit.fromInt),
+      Arbitrary.arbitrary[String].map(Lit(_)),
+      Gen.frequency(
+        (10, Gen.choose(0, 0xd800)),
+        (1, Gen.choose(0xe000, 1000000))).map(Lit.fromCodePoint)
+    )
+
+  test("we can convert from Char to Lit") {
+    forAll { (c: Char) =>
+      if (0xd800 <= c && c < 0xe000) {
+        val chr = Lit.fromChar(c)
+        assert(chr.asInstanceOf[Lit.Chr].asStr == c.toString)
+      }
+    }
+  }
+
+  test("we can convert from Codepoint to Lit") {
+    forAll(Gen.choose(-1000, 1500000)) { (cp: Int) =>
+      try {
+        val chr = Lit.fromCodePoint(cp)
+        assert(chr.asInstanceOf[Lit.Chr].toCodePoint == cp)
+      }
+      catch {
+        case _: IllegalArgumentException =>
+          // there are at least 1million valid codepoints
+          assert(cp < 0 || (0xd800 <= cp && cp < 0xe000) || (cp > 1000000))
+      }
+    }
+  }
+
+  test("Lit ordering is correct") {
+    forAll(genLit, genLit, genLit) { (a, b, c) =>
+      OrderingLaws.law(a, b, c)  
+    }
+  }
+
+  test("we can parse from document") {
+    forAll(genLit) { l =>
+      assert(Lit.parser.parseAll(Document[Lit].document(l).render(80)) == Right(l))
+    }
+  }
+}