Add feed validation and display

packages/lib/__tests__/Tools.test.ts

@@ -310,6 +310,61 @@ describe("Tools", () => {
     })
   })
 
+  describe("displayList", () => {
+    it("should return an empty string when the list is empty", () => {
+      const list = []
+      const output = T.displayList(list)
+
+      expect(output).toEqual("")
+    })
+
+    it("should return a single entry when list length is one", () => {
+      const list = ["Apple"]
+      const output = T.displayList(list)
+
+      expect(output).toEqual("Apple")
+    })
+
+    it("should return a string of both items when the list length is two", () => {
+      const list = ["Apple", "Banana"]
+      const output = T.displayList(list)
+
+      expect(output).toEqual("Apple and Banana")
+    })
+
+    it("should return a string of all items when the list length is three", () => {
+      const list = ["Apple", "Banana", "Cherry"]
+      const output = T.displayList(list)
+
+      expect(output).toEqual("Apple, Banana, and Cherry")
+    })
+
+    it("should return a truncated string of all items when the list is long", () => {
+      const list = [
+        "Apple",
+        "Banana",
+        "Orange",
+        "Pear",
+        "Grapes",
+        "Mango",
+        "Pineapple",
+        "Kiwi",
+        "Strawberry",
+        "Blueberry",
+      ]
+      const output = T.displayList(list)
+
+      expect(output).toEqual("Apple, Banana, Orange, Pear, Grapes, Mango, and 4 others")
+    })
+
+    it("should return a string of both items with list of two numbers", () => {
+      const list = [7, 17]
+      const output = T.displayList(list)
+
+      expect(output).toEqual("7 and 17")
+    })
+  })
+
   describe("Collection Operations", () => {
     it("should handle group operations", () => {
       const items = [