Add option "url_safe" to "to_base64" function

README.md

@@ -905,8 +905,12 @@ to_json("<sourceField>"[, pretty: "<boolean>"][, error_string: "<errorValue>"])
 
 Replaces the value with its Base64 encoding.
 
+Options:
+
+-`url_safe`: Perform URL-safe encoding (uses Base64URL format). (Default: `false`)
+
 ```perl
-to_base64("<sourceField>")
+to_base64("<sourceField>"[, url_safe: "<boolean>"])
 ```
 
 [Example in Playground](https://metafacture.org/playground/?example=to_base64)

metafix/src/main/java/org/metafacture/metafix/FixMethod.java

@@ -680,7 +680,10 @@ public void apply(final Metafix metafix, final Record record, final List<String>
     to_base64 {
         @Override
         public void apply(final Metafix metafix, final Record record, final List<String> params, final Map<String, String> options) {
-            record.transform(params.get(0), s -> Base64.getEncoder().encodeToString(s.getBytes()));
+            final boolean urlSafe = getBoolean(options, "url_safe");
+            final Base64.Encoder encoder = urlSafe ? Base64.getUrlEncoder() : Base64.getEncoder();
+
+            record.transform(params.get(0), s -> encoder.encodeToString(s.getBytes()));
         }
     },
     to_json {

metafix/src/test/java/org/metafacture/metafix/MetafixMethodTest.java

@@ -36,6 +36,8 @@
 @ExtendWith(MetafixToDo.Extension.class)
 public class MetafixMethodTest {
 
+    private static final String YOUTUBE_URL = "https://www.youtube.com/watch?v=daLgsPSvD9A";
+
     @Mock
     private StreamReceiver streamReceiver;
 
@@ -4084,6 +4086,37 @@ public void shouldTransformStringToBase64() {
         );
     }
 
+    @Test
+    public void shouldTransformUrlSafeToBase64() {
+        urlToBase64(",url_safe:'true'", "aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g_dj1kYUxnc1BTdkQ5QQ==");
+    }
+
+    @Test
+    public void shouldTransformNotUrlSafeToBase64AsDefault() {
+        urlToBase64("", "aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1kYUxnc1BTdkQ5QQ==");
+    }
+
+    private void urlToBase64(final String option, final String expected) {
+        MetafixTestHelpers.assertFix(streamReceiver, Arrays.asList(
+                "to_base64('data.title'" + option + ")"
+            ),
+            i -> {
+                i.startRecord("1");
+                i.startEntity("data");
+                i.literal("title", YOUTUBE_URL);
+                i.endEntity();
+                i.endRecord();
+            },
+            o -> {
+                o.get().startRecord("1");
+                o.get().startEntity("data");
+                o.get().literal("title", expected);
+                o.get().endEntity();
+                o.get().endRecord();
+            }
+        );
+    }
+
     @Test // checkstyle-disable-line JavaNCSS
     public void shouldCreateVariableFromLiteralValue() {
         MetafixTestHelpers.assertFix(streamReceiver, Arrays.asList(