Checkpoint

tests/prolog/builtins/ListOperatorsTests.kt

@@ -0,0 +1,60 @@
+package prolog.builtins
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Disabled
+import org.junit.jupiter.api.Test
+import prolog.ast.lists.List.Cons
+import prolog.ast.lists.List.Empty
+import prolog.ast.terms.Atom
+
+class ListOperatorsTests {
+    @Test
+    fun `size empty list is 0`() {
+        assertEquals(0, Empty.size.value, "Expected size of empty list to be 0")
+    }
+
+    @Test
+    fun `size of singleton is 1`() {
+        val list = Cons(Atom("a"), Empty)
+
+        assertEquals(1, list.size.value, "Expected size of singleton list to be 1")
+    }
+
+    @Test
+    fun `size of list with five elements is 5`() {
+        val list = Cons(Atom("a"), Cons(Atom("b"), Cons(Atom("c"), Cons(Atom("d"), Cons(Atom("e"), Empty)))))
+
+        assertEquals(5, list.size.value, "Expected size of list with five elements to be 5")
+    }
+
+    @Test
+    fun `member(a, list of a)`() {
+        val atom = Atom("a")
+        val list = Cons(atom, Empty)
+
+        val member = Member(atom, list)
+
+        val result = member.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected one solution")
+        assertTrue(result[0].isSuccess, "Expected success")
+        assertTrue(result[0].getOrNull()!!.isEmpty(), "Expected empty substitution map")
+    }
+
+    @Disabled("Not required functionality")
+    @Test
+    fun `member with variable in list`() {
+        val atom = Atom("a")
+        val variable = Atom("X")
+        val list = Cons(variable, Empty)
+
+        val member = Member(atom, list)
+
+        val result = member.satisfy(emptyMap()).toList()
+
+        assertEquals(1, result.size, "Expected one solution")
+        assertTrue(result[0].isSuccess, "Expected success")
+        assertEquals(atom, result[0].getOrNull()!![variable], "Expected variable to be unified with atom")
+    }
+}