diff --git a/test/elementContains.test.js b/test/elementContains.test.js
index 2a46c2d49..a1898278f 100644
--- a/test/elementContains.test.js
+++ b/test/elementContains.test.js
@@ -4,3 +4,13 @@ const {elementContains} = require('./_30s.js');
 test('elementContains is a Function', () => {
   expect(elementContains).toBeInstanceOf(Function);
 });
+test('elementContains returns true', () => {
+  let p = document.createElement('div');
+  let c = p.appendChild(document.createElement('div'));
+  expect(elementContains(p, c)).toBeTruthy();
+});
+test('elementContains returns false', () => {
+  let p = document.createElement('div');
+  let c = document.createElement('div');
+  expect(elementContains(p, c)).toBeFalsy();
+});
diff --git a/test/elementIsVisibleInViewport.test.js b/test/elementIsVisibleInViewport.test.js
index 68f0fa1d2..274ec9c39 100644
--- a/test/elementIsVisibleInViewport.test.js
+++ b/test/elementIsVisibleInViewport.test.js
@@ -4,3 +4,11 @@ const {elementIsVisibleInViewport} = require('./_30s.js');
 test('elementIsVisibleInViewport is a Function', () => {
   expect(elementIsVisibleInViewport).toBeInstanceOf(Function);
 });
+test('elementIsVisibleInViewport returns a boolean', () => {
+  let el = document.createElement('div');
+  expect(typeof elementIsVisibleInViewport(el)).toBe('boolean');
+});
+test('elementIsVisibleInViewport returns a boolean', () => {
+  let el = document.createElement('div');
+  expect(typeof elementIsVisibleInViewport(el, true)).toBe('boolean');
+});
diff --git a/test/getScrollPosition.test.js b/test/getScrollPosition.test.js
index c061d268b..1863fe74f 100644
--- a/test/getScrollPosition.test.js
+++ b/test/getScrollPosition.test.js
@@ -4,3 +4,14 @@ const {getScrollPosition} = require('./_30s.js');
 test('getScrollPosition is a Function', () => {
   expect(getScrollPosition).toBeInstanceOf(Function);
 });
+test('getScrollPosition returns an object with x and y values', () => {
+  let scrollPos = getScrollPosition();
+  expect(typeof scrollPos.x).toBe('number');
+  expect(typeof scrollPos.y).toBe('number');
+});
+test('getScrollPosition returns an object with x and y values', () => {
+  let el = document.createElement('div');
+  let scrollPos = getScrollPosition(el);
+  expect(typeof scrollPos.x).toBe('number');
+  expect(typeof scrollPos.y).toBe('number');
+});
diff --git a/test/getStyle.test.js b/test/getStyle.test.js
index c6d6e0a1a..84c75fb72 100644
--- a/test/getStyle.test.js
+++ b/test/getStyle.test.js
@@ -4,3 +4,8 @@ const {getStyle} = require('./_30s.js');
 test('getStyle is a Function', () => {
   expect(getStyle).toBeInstanceOf(Function);
 });
+test('getStyle returns the proper value', () => {
+  let el = document.createElement('div');
+  el.setAttribute('style', 'font-size: 20px;');
+  expect(getStyle(el, 'font-size')).toBe('20px');
+});
diff --git a/test/hasClass.test.js b/test/hasClass.test.js
index d7f796238..d8d3307a5 100644
--- a/test/hasClass.test.js
+++ b/test/hasClass.test.js
@@ -4,3 +4,8 @@ const {hasClass} = require('./_30s.js');
 test('hasClass is a Function', () => {
   expect(hasClass).toBeInstanceOf(Function);
 });
+test('hasClass returns the proper value', () => {
+  let el = document.createElement('div');
+  el.classList.add('myClass');
+  expect(hasClass(el, 'myClass')).toBeTruthy();
+});