diff --git a/src/test/java/org/nwapw/abacus/tests/LexerTests.java b/src/test/java/org/nwapw/abacus/tests/LexerTests.java
index c6c0a75..268a06c 100644
--- a/src/test/java/org/nwapw/abacus/tests/LexerTests.java
+++ b/src/test/java/org/nwapw/abacus/tests/LexerTests.java
@@ -15,6 +15,7 @@ public class LexerTests {
         lexer.register("abc", 0);
         lexer.register("def", 1);
         List<Match<Integer>> matchedIntegers = lexer.lexAll("abcdefabc", 0, Integer::compare);
+        Assert.assertNotNull(matchedIntegers);
         Assert.assertEquals(matchedIntegers.get(0).getType(), Integer.valueOf(0));
         Assert.assertEquals(matchedIntegers.get(1).getType(), Integer.valueOf(1));
         Assert.assertEquals(matchedIntegers.get(2).getType(), Integer.valueOf(0));
@@ -40,5 +41,93 @@ public class LexerTests {
         lexer.register("a?", 0);
         Assert.assertNull(lexer.lexAll("", 0, Integer::compare));
     }
+
+    @Test
+    public void testOneOrMore(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("a+", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("aaaa", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 1);
+    }
+
+    @Test
+    public void testZeroOrMore(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("a*", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("aaaa", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 1);
+    }
+
+    @Test
+    public void testZeroOrOne(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("a?", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("aaaa", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 4);
+    }
+
+    @Test
+    public void testGreedyMatching(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("a*a", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("aaaa", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 1);
+    }
+
+    @Test
+    public void testAnyCharacter(){
+        String testString = "abcdef";
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register(".", 0);
+        List<Match<Integer>> tokens = lexer.lexAll(testString, 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), testString.length());
+        for(int i = 0; i < tokens.size(); i++){
+            Assert.assertEquals(testString.substring(i, i + 1), tokens.get(i).getContent());
+        }
+    }
+
+    @Test
+    public void testBasicGroup(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("(abc)", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("abc", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 1);
+        Assert.assertEquals(tokens.get(0).getContent(), "abc");
+    }
+
+    @Test
+    public void testBasicRangeSuccess(){
+        String testString = "abcdef";
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("[a-f]", 0);
+        List<Match<Integer>> tokens = lexer.lexAll(testString, 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(testString.length(), tokens.size());
+        for(int i = 0; i < tokens.size(); i++){
+            Assert.assertEquals(testString.substring(i, i + 1), tokens.get(i).getContent());
+        }
+    }
+
+    @Test
+    public void testBasicRangeFailure(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("[a-f]", 0);
+        Assert.assertNull(lexer.lexAll("g", 0, Integer::compare));
+    }
     
+    @Test
+    public void testGroupAndOperator(){
+        Lexer<Integer> lexer = new Lexer<>();
+        lexer.register("(abc)+", 0);
+        List<Match<Integer>> tokens = lexer.lexAll("abcabc", 0, Integer::compare);
+        Assert.assertNotNull(tokens);
+        Assert.assertEquals(tokens.size(), 1);
+    }
+
 }