Add specs for InputEncoder

catculator-core/src/main/scala/pl/writeonly/catculator/core/adt/calculus/InputEncoder.scala

@@ -15,7 +15,7 @@ object InputEncoder {
       },
   )
 
-  private def encodeInput(input: List[Natural]): CombinatorBT = input
+  def encodeInput(input: List[Natural]): CombinatorBT = input
     .foldRight(falseCom) { case (n, l) =>
       cons(church(n), l)
     }

catculator-core/src/test/scala/pl/writeonly/catculator/core/adt/calculus/InputEncoderSpec.scala

@@ -0,0 +1,48 @@
+package pl.writeonly.catculator.core.adt.calculus
+
+import pl.writeonly.catculator.core.adt.calculus.Combinator.*
+import pl.writeonly.catculator.core.adt.calculus.Constants.*
+import pl.writeonly.catculator.core.adt.tree.BinaryTree.*
+
+import pl.writeonly.catculator.core.TableDrivenPropertySpec
+
+import spire.math.Natural
+
+class InputEncoderSpec extends TableDrivenPropertySpec {
+
+  private val oneCom = Node(Leaf(S), Node(Node(Leaf(S), Node(Node(Leaf(K), Leaf(S)), Leaf(K))), Node(Leaf(K), Leaf(I))))
+  private var zeroListCom = Node(Leaf(S), Node(Node(Leaf(S), Node(Leaf(I), Node(Leaf(K), Node(Leaf(K), Leaf(I))))), Node(Leaf(K), Node(Leaf(K), Leaf(I)))))
+
+  it should "church number" in {
+
+    val combinators = Table(
+      ("input", "ast"),
+      (Natural.zero, falseCom),
+      (Natural.one, oneCom),
+    )
+    forAll(combinators) { (input, code) =>
+      InputEncoder.church(input) shouldBe code
+    }
+  }
+
+  it should "encode input List" in {
+    val combinators = Table(
+      ("input", "ast"),
+      (List(Natural.zero), zeroListCom),
+    )
+    forAll(combinators) { (input, code) =>
+      InputEncoder.encodeInput(input) shouldBe code
+    }
+  }
+
+  it should "encode input String" in {
+    val combinators = Table(
+      ("input", "ast"),
+      ("", falseCom),
+    )
+    forAll(combinators) { (input, code) =>
+      InputEncoder.readInput(input) shouldBe code
+    }
+  }
+
+}