From 7cbf2eafcd03e4702734967a4fc8dbb340bb013e Mon Sep 17 00:00:00 2001
From: DiegoMarti2 <150871541+DiegoMarti2@users.noreply.github.com>
Date: Sat, 17 Feb 2024 14:12:34 -0800
Subject: [PATCH] baeldung-articles : BAEL-7442 (#15887)

* baeldung-articles : BAEL-7442

Check if String is Base64 Encoded (commit)

* Update CheckIfStringIsBased64UnitTest.java
---
 .../CheckIfStringIsBased64UnitTest.java       | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/checkifstringisbased64/CheckIfStringIsBased64UnitTest.java

diff --git a/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/checkifstringisbased64/CheckIfStringIsBased64UnitTest.java b/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/checkifstringisbased64/CheckIfStringIsBased64UnitTest.java
new file mode 100644
index 0000000000..fdb543b3f5
--- /dev/null
+++ b/core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/checkifstringisbased64/CheckIfStringIsBased64UnitTest.java
@@ -0,0 +1,40 @@
+package com.baeldung.checkifstringisbased64;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Base64;
+import java.util.regex.Pattern;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class CheckIfStringIsBased64UnitTest {
+
+    @Test
+    public void givenBase64EncodedString_whenDecoding_thenNoException() {
+        try {
+            Base64.getDecoder().decode("SGVsbG8gd29ybGQ=");
+            assertTrue(true);
+        } catch (IllegalArgumentException e) {
+            fail("Unexpected exception: " + e.getMessage());
+        }
+    }
+
+    @Test
+    public void givenNonBase64String_whenDecoding_thenCatchException() {
+        try {
+            Base64.getDecoder().decode("Hello world!");
+            fail("Expected IllegalArgumentException was not thrown");
+        } catch (IllegalArgumentException e) {
+            assertTrue(true);
+        }
+    }
+
+    @Test
+    public void givenString_whenOperatingRegex_thenCheckIfItIsBase64Encoded() {
+        Pattern BASE64_PATTERN = Pattern.compile(
+                "^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$"
+        );
+
+        assertTrue(BASE64_PATTERN.matcher("SGVsbG8gd29ybGQ=").matches());
+    }
+}