diff --git a/tests/chop.js b/tests/chop.js
index 8106337c..f087589f 100644
--- a/tests/chop.js
+++ b/tests/chop.js
@@ -1,12 +1,11 @@
-var ok = require('assert').ok;
+var deepEqual = require('assert').deepEqual;
 var chop = require('../chop');
 
 
 test('#chop', function(){
-  ok(chop(null, 2).length === 0, 'output []');
-  ok(chop('whitespace', 2).length === 5, 'output [wh, it, es, pa, ce]');
-  ok(chop('whitespace', 3).length === 4, 'output [whi, tes, pac, e]');
-  ok(chop('whitespace')[0].length === 10, 'output [whitespace]');
-  ok(chop(12345, 1).length === 5, 'output [1, 2, 3,  4, 5]');
+  deepEqual(chop(null, 2), [], 'output []');
+  deepEqual(chop('whitespace', 2), ['wh', 'it', 'es', 'pa', 'ce'], 'output [wh, it, es, pa, ce]');
+  deepEqual(chop('whitespace', 3), ['whi', 'tes', 'pac', 'e'], 'output [whi, tes, pac, e]');
+  deepEqual(chop('whitespace'), ['whitespace'], 'output [whitespace]');
+  deepEqual(chop(12345, 1), ['1', '2', '3', '4', '5'], 'output [1, 2, 3, 4, 5]');
 });
-
diff --git a/tests/clean.js b/tests/clean.js
index a613cab2..fa952c1a 100644
--- a/tests/clean.js
+++ b/tests/clean.js
@@ -4,8 +4,9 @@ var clean = require('../clean');
 
 test('#clean', function() {
   equal(clean(' foo    bar   '), 'foo bar');
-  equal(clean(123), '123');
-  equal(clean(''), '', 'claning empty string returns empty string');
-  equal(clean(null), '', 'claning null returns empty string');
-  equal(clean(undefined), '', 'claning undefined returns empty string');
+  equal(clean('foo bar'), 'foo bar', 'cleaning a string not containing multiple spaces returns string itself');
+  equal(clean(123), '123', 'cleaning number returns it\'s string representation');
+  equal(clean(''), '', 'cleaning empty string returns empty string');
+  equal(clean(null), '', 'cleaning null returns empty string');
+  equal(clean(undefined), '', 'cleaning undefined returns empty string');
 });
diff --git a/tests/count.js b/tests/count.js
index 3e765ed8..08e62e14 100644
--- a/tests/count.js
+++ b/tests/count.js
@@ -6,6 +6,7 @@ test('#count', function(){
   equal(count('Hello world', 'l'), 3);
   equal(count('Hello world', 'Hello'), 1);
   equal(count('Hello world', 'foo'), 0);
+  equal(count('Hello world', 'Hello world'), 1);
   equal(count('x.xx....x.x', 'x'), 5);
   equal(count('', 'x'), 0);
   equal(count(null, 'x'), 0);
@@ -19,4 +20,3 @@ test('#count', function(){
   equal(count(null, null), 0);
   equal(count(undefined, undefined), 0);
 });
-
diff --git a/tests/endsWith.js b/tests/endsWith.js
index 5836a534..1f14833c 100644
--- a/tests/endsWith.js
+++ b/tests/endsWith.js
@@ -5,6 +5,7 @@ var endsWith = require('../endsWith');
 
 test('#endsWith', function() {
   ok(endsWith('foobar', 'bar'), 'foobar ends with bar');
+  ok(endsWith('foobar', ''), 'foobar ends with empty string');
   ok(endsWith('foobarfoobar', 'bar'), 'foobar ends with bar');
   ok(endsWith('foo', 'o'), 'foobar ends with o');
   ok(endsWith('foobar', 'bar'), 'foobar ends with bar');
@@ -39,4 +40,3 @@ test('#endsWith', function() {
   strictEqual(endsWith('vader', 'der', 3), false);
   strictEqual(endsWith('vader', 'der', 4), false);
 });
-
diff --git a/tests/include.js b/tests/include.js
index ef2d3a8b..ccf5a751 100644
--- a/tests/include.js
+++ b/tests/include.js
@@ -6,10 +6,10 @@ var s = require('../');
 test('#include', function() {
   ok(include('foobar', 'bar'), 'foobar includes bar');
   ok(!include('foobar', 'buzz'), 'foobar does not includes buzz');
+  ok(include('foobar', ''), 'foobar includes empty string');
   ok(include(12345, 34), '12345 includes 34');
   ok(!s.contains(12345, 6), '12345 does not include 6');
   ok(!include('', 34), 'empty string includes 34');
   ok(!include(null, 34), 'null includes 34');
   ok(include(null, ''), 'null includes empty string');
 });
-
diff --git a/tests/insert.js b/tests/insert.js
index 612003c0..5af616fb 100644
--- a/tests/insert.js
+++ b/tests/insert.js
@@ -6,10 +6,12 @@ test('#insert', function(){
   equal(insert('Hello ', 6, 'Jessy'), 'Hello Jessy');
   equal(insert('Hello', 0, 'Jessy '), 'Jessy Hello');
   equal(insert('Hello ', 100, 'Jessy'), 'Hello Jessy');
+  equal(insert('Hello', 2, ''), 'Hello');
+  equal(insert('Hello', 2, null), 'Hello');
+  equal(insert('Hello', 2, undefined), 'Hello');
   equal(insert('', 100, 'Jessy'), 'Jessy');
   equal(insert(null, 100, 'Jessy'), 'Jessy');
   equal(insert(undefined, 100, 'Jessy'), 'Jessy');
   equal(insert(12345, 5, 'Jessy'), '12345Jessy');
   equal(insert(12345, 3, 'Jessy'), '123Jessy45');
 });
-
diff --git a/tests/lpad.js b/tests/lpad.js
index d2be7829..898fdeae 100644
--- a/tests/lpad.js
+++ b/tests/lpad.js
@@ -10,5 +10,8 @@ test('#lpad', function() {
   equal(lpad('', 2), '  ');
   equal(lpad(null, 2), '  ');
   equal(lpad(undefined, 2), '  ');
+  equal(lpad('Hello', 0), 'Hello');
+  equal(lpad('Hello', -8), 'Hello');
+  equal(lpad('Hello', undefined), 'Hello');
+  equal(lpad('Hello', null), 'Hello');
 });
-
diff --git a/tests/lrpad.js b/tests/lrpad.js
index 0b95088d..948fb4e6 100644
--- a/tests/lrpad.js
+++ b/tests/lrpad.js
@@ -12,5 +12,8 @@ test('#lrpad', function() {
   equal(lrpad('', 2), '  ');
   equal(lrpad(null, 2), '  ');
   equal(lrpad(undefined, 2), '  ');
+  equal(lrpad('Hello', 0), 'Hello');
+  equal(lrpad('Hello', -8), 'Hello');
+  equal(lrpad('Hello', undefined), 'Hello');
+  equal(lrpad('Hello', null), 'Hello');
 });
-
diff --git a/tests/repeat.js b/tests/repeat.js
index 5784d1f7..7102e35a 100644
--- a/tests/repeat.js
+++ b/tests/repeat.js
@@ -12,5 +12,6 @@ test('#repeat', function() {
   equal(repeat('', 2), '');
   equal(repeat(null, 2), '');
   equal(repeat(undefined, 2), '');
+  equal(repeat('foo', null), '');
+  equal(repeat('foo', undefined), '');
 });
-
diff --git a/tests/rpad.js b/tests/rpad.js
index 7cc073ca..be90765b 100644
--- a/tests/rpad.js
+++ b/tests/rpad.js
@@ -11,5 +11,8 @@ test('#rpad', function() {
   equal(rpad('', 2), '  ');
   equal(rpad(null, 2), '  ');
   equal(rpad(undefined, 2), '  ');
+  equal(rpad('Hello', 0), 'Hello');
+  equal(rpad('Hello', -8), 'Hello');
+  equal(rpad('Hello', undefined), 'Hello');
+  equal(rpad('Hello', null), 'Hello');
 });
-