test: add unit tests

lib/linkedlist/linked_list.ak

@@ -9,15 +9,15 @@ use linkedlist/utils
 
 pub fn init(common: Common) -> Bool {
   let must_spend_nodes = list.length(common.node_inputs) > 0
-  let must_exactly_one_node_outputs = list.length(common.node_outputs) == 1
+  let must_exactly_one_node_output = list.length(common.node_outputs) == 1
   let must_mint_correctly =
     utils.validate_mint(
       common.mint,
       common.own_cs,
       constants.origin_node_token_name,
       1,
     )
-  must_spend_nodes? && must_exactly_one_node_outputs? && must_mint_correctly?
+  must_spend_nodes? && must_exactly_one_node_output? && must_mint_correctly?
 }
 
 pub fn deinit(common: Common) -> Bool {

lib/linkedlist/tests.ak

@@ -0,0 +1,25 @@
+use linkedlist/utils.{div_ceil}
+
+// Test Case 1
+// Test when a is divisible by b
+test div_ceil_1() {
+  div_ceil(10, 5) == 2
+}
+
+// Test Case 2
+// Test when a is not divisible by b
+test div_ceil_2() {
+  div_ceil(7, 3) == 3
+}
+
+// Test Case 3
+// Test when a is 0
+test div_ceil_3() {
+  div_ceil(0, 5) == 0
+}
+
+// Test Case 4
+// Test when b is 1
+test div_ceil_4() {
+  div_ceil(10, 1) == 10
+}