diff --git a/test/filterNonUnique.test.js b/test/filterNonUnique.test.js
index 459c67282..2d94bb77f 100644
--- a/test/filterNonUnique.test.js
+++ b/test/filterNonUnique.test.js
@@ -7,3 +7,10 @@ test('filterNonUnique is a Function', () => {
 test('Filters out the non-unique values in an array', () => {
   expect(filterNonUnique([1, 2, 2, 3, 4, 4, 5])).toEqual([1, 3, 5]);
 });
+test('Works with multiple types of values in the same array', () => {
+  expect(filterNonUnique([1, 2, 2, 3, 4, 4, 5, true, 'repeated text', 'repeated text', 'unique text'])).toEqual([1, 3, 5, true, 'unique text']);
+});
+test('No error on empty array', () => {
+  expect(filterNonUnique([])).toEqual([]);
+});
+
diff --git a/test/squareSum.test.js b/test/squareSum.test.js
index 13b31a2af..69b6b8962 100644
--- a/test/squareSum.test.js
+++ b/test/squareSum.test.js
@@ -7,3 +7,11 @@ test('squareSum is a Function', () => {
 test('squareSum returns the proper result', () => {
   expect(squareSum(2, 3, 4)).toBe(29);
 });
+
+test('works with negative numbers', () => {
+  expect(squareSum(-2, 3, -4)).toBe(29);
+});
+
+test('NaN when parameters have text', () => {
+  expect(squareSum(-2, 3, -4, 'text')).toBe(NaN);
+});
diff --git a/test/uniqueSymmetricDifference.test.js b/test/uniqueSymmetricDifference.test.js
index d9fa598b6..eaf97a6a1 100644
--- a/test/uniqueSymmetricDifference.test.js
+++ b/test/uniqueSymmetricDifference.test.js
@@ -10,3 +10,13 @@ test('Returns the symmetric difference between two arrays.', () => {
 test('Does not return duplicates from one array', () => {
   expect(uniqueSymmetricDifference([1, 2, 2], [1, 3, 1])).toEqual([2, 3]);
 });
+test('Works with different size arrays', () => {
+  expect(uniqueSymmetricDifference([1, 2, 2, 4], [1, 3, 1, 4, 5, 6])).toEqual([2, 3, 5, 6]);
+});
+test('Works with different types in the same array', () => {
+  expect(uniqueSymmetricDifference([1, 2, 'duplicate text', 'unique text'], [1, 3, 'duplicate text'])).toEqual([2, 'unique text', 3]);
+});
+test('Works when one array is empty', () => {
+  expect(uniqueSymmetricDifference([1, 2, 2, 3], [])).toEqual([1, 2, 3]);
+});
+