diff --git a/src/main/java/com/ctci/arraysandstrings/CheckPermutation.java b/src/main/java/com/ctci/arraysandstrings/CheckPermutation.java
index dbf7c795..d9b68fa3 100644
--- a/src/main/java/com/ctci/arraysandstrings/CheckPermutation.java
+++ b/src/main/java/com/ctci/arraysandstrings/CheckPermutation.java
@@ -1,5 +1,7 @@
 package com.ctci.arraysandstrings;
 
+import org.junit.Assert;
+import org.junit.Test;
 import java.util.Arrays;
 
 /**
@@ -54,6 +56,48 @@ private static boolean isOnePermutationOfOtherGivenThatStringsContainOnlyAscii(S
         }
         return true;
     }
+    
+    @Test
+	public void isOnePermutationOfOther_tc1_differentlength() {
+		String s1 = "rama";
+		String s2 = "mar";
+		Assert.assertFalse(isOnePermutationOfOther(s1, s2));
+	}
+    
+    @Test
+	public void isOnePermutationOfOther_tc2_isPermutation() {
+    	String s1 = "ram";
+		String s2 = "mar";
+		Assert.assertTrue(isOnePermutationOfOther(s1, s2));
+	}
+    
+    @Test
+	public void isOnePermutationOfOther_tc3_notPermutation() {
+    	String s1 = "rama";
+		String s2 = "marA";
+		Assert.assertFalse(isOnePermutationOfOther(s1, s2));
+	}
+    
+    @Test
+	public void isOnePermutationOfOtherGivenThatStringsContainOnlyAscii_tc1_differentlength() {
+		String s1 = "rama";
+		String s2 = "mar";
+		Assert.assertFalse(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii(s1, s2));
+	}
+    
+    @Test
+	public void isOnePermutationOfOtherGivenThatStringsContainOnlyAscii_tc2_isPermutation() {
+    	String s1 = "ram";
+		String s2 = "mar";
+		Assert.assertTrue(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii(s1, s2));
+	}
+    
+    @Test
+	public void isOnePermutationOfOtherGivenThatStringsContainOnlyAscii_tc3_notPermutation() {
+    	String s1 = "rama";
+		String s2 = "marA";
+		Assert.assertFalse(isOnePermutationOfOtherGivenThatStringsContainOnlyAscii(s1, s2));
+	}
 
     public static void main(String[] args) {
         System.out.println(isOnePermutationOfOther("ram", "mar"));
diff --git a/src/main/java/com/ctci/arraysandstrings/IsUnique.java b/src/main/java/com/ctci/arraysandstrings/IsUnique.java
index 895d16b3..2f58d2e4 100644
--- a/src/main/java/com/ctci/arraysandstrings/IsUnique.java
+++ b/src/main/java/com/ctci/arraysandstrings/IsUnique.java
@@ -1,5 +1,8 @@
 package com.ctci.arraysandstrings;
 
+import org.junit.Assert;
+import org.junit.Test;
+
 /**
  * @author rampatra
  * @since 18/11/2018
@@ -32,6 +35,54 @@ private static boolean hasAllUniqueCharactersWhenStringContainsAllLowercase(Stri
         return true;
     }
 
+    @Test
+	public void hasAllUniqueCharacters_tc1_null() {
+		String s = null;
+		Assert.assertFalse(hasAllUniqueCharacters(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharacters_tc2_greaterThan128() {
+		String s = "Currently, each country has its own language, its own characters. Extended ASCII encoding was born with the goal of being diverse in that language";
+		Assert.assertFalse(hasAllUniqueCharacters(s));
+	}
+
+	@Test
+	public void hasAllUniqueCharacters_tc3_notUnique() {
+		String s = "rama";
+		Assert.assertFalse(hasAllUniqueCharacters(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharacters_tc4_Unique() {
+		String s = "ram";
+		Assert.assertTrue(hasAllUniqueCharacters(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharacters_tc5_UniqueWithCapital() {
+		String s = "ramA";
+		Assert.assertTrue(hasAllUniqueCharacters(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharactersWhenStringContainsAllLowercase_tc1_notUnique() {
+		String s = "rama";
+		Assert.assertFalse(hasAllUniqueCharactersWhenStringContainsAllLowercase(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharactersWhenStringContainsAllLowercase_tc2_Unique() {
+		String s = "ram";
+		Assert.assertTrue(hasAllUniqueCharactersWhenStringContainsAllLowercase(s));
+	}
+	
+	@Test
+	public void hasAllUniqueCharactersWhenStringContainsAllLowercase_tc3_UniqueWithCapital() {
+		String s = "ramA";
+		Assert.assertFalse(hasAllUniqueCharactersWhenStringContainsAllLowercase(s));
+	}
+	
     public static void main(String[] args) {
         String s = "ram";
         System.out.println(hasAllUniqueCharacters(s));