ZA-ITP-May-2025 | Christian Mayamba | Module-Data-Groups | Week 1

Sprint-1/implement/dedupe.js

@@ -1 +1,17 @@
-function dedupe() {}
+function dedupe(array) {
+  if (array.length === 0) {
+    return [];
+  }
+
+  const duplicates = array.filter(
+    (item, index) => array.indexOf(item) !== index
+  );
+
+  const set2 = new Set(duplicates);
+  return array.filter((item) => !set2.has(item));
+}
+
+testVar = [1, 20, "hi", 20, 6, 9, "hey"];
+console.log(dedupe(testVar));
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,12 +16,20 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 // 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");
+test("given an empty array, it returns an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("array with no duplicates, it returns a copy of the array", () => {
+  expect(dedupe([10, 20, 30])).toEqual([10, 20, 30]);
+});
 
 // 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("array with strings and numbers, it should remove duplicates", () => {
+  expect(dedupe([10, "hi", "hey", 20, "hey", 30])).toEqual([10, "hi", 20, 30]);
+});