Some tests for Base64 encoding.

crypto/src/test/java/org/springframework/security/crypto/codec/Base64Tests.java

@@ -0,0 +1,34 @@
+package org.springframework.security.crypto.codec;
+
+import static org.junit.Assert.*;
+
+import org.junit.*;
+
+/**
+ * @author Luke Taylor
+ */
+public class Base64Tests {
+
+    @Test
+    public void isBase64ReturnsTrueForValidBase64() {
+        new Base64(); // unused
+
+        assertTrue(Base64.isBase64(new byte[]{ (byte)'A',(byte)'B',(byte)'C',(byte)'D'}));
+    }
+
+    @Test
+    public void isBase64ReturnsFalseForInvalidBase64() throws Exception {
+        // Include invalid '`' character
+        assertFalse(Base64.isBase64(new byte[]{ (byte)'A',(byte)'B',(byte)'C',(byte)'`'}));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void isBase64RejectsNull() {
+        Base64.isBase64(null);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void isBase64RejectsInvalidLength() {
+        Base64.isBase64(new byte[]{ (byte)'A'});
+    }
+}