Added tests and implemented solution for the implement section - dedupe.js and dedupe.test.js

Author: Konvaly

Sprint-1/implement/dedupe.js

@@ -1 +1,15 @@
-function dedupe() {}
+function dedupe(arr) {
+  if (arr.length === 0) return [];
+
+  const noDupsArr = [];
+  const seenItems = new Set();
+
+  for (const el of arr) {
+    if (!seenItems.has(el)) {
+      noDupsArr.push(el);
+      seenItems.add(el);
+    }
+  }
+  return noDupsArr;
+}
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -12,16 +12,27 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 */
 
 // Acceptance Criteria:
+describe("dedupe", () => {
+  // Given an empty array
+  // When passed to the dedupe function
+  // Then it should return an empty array
+  test("given an empty array, returns an empty array", () => {
+    expect(dedupe([])).toEqual([]);
+  });
 
-// Given an empty array
-// When passed to the dedupe function
-// Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+  // Given an array with no duplicates
+  // When passed to the dedupe function
+  // Then it should return a copy of the original array
+  test("given an array with no duplicates, returns a copy of the original array", () => {
+    const input = [1, 65, 2, 298, 3, 729];
+    expect(dedupe(input)).toEqual([1, 65, 2, 298, 3, 729]);
+  });
 
-// Given an array with no duplicates
-// When passed to the dedupe function
-// Then it should return a copy of the original array
-
-// Given an array with strings or numbers
-// When passed to the dedupe function
-// Then it should remove the duplicate values, preserving the first occurence of each element
+  // Given an array with strings or numbers
+  // When passed to the dedupe function
+  // Then it should remove the duplicate values, preserving the first occurence of each element
+  test("given an array with duplicates, removes duplicate values preserving the first occurrence", () => {
+    const input = ["a", "b", "a", "c", "b", "d", "e", "d", "c", "a", "b"];
+    expect(dedupe(input)).toEqual(["a", "b", "c", "d", "e"]);
+  });
+});