Update snippets for base64 filters

Author: jasmith-hs

src/main/java/com/hubspot/jinjava/lib/filter/Base64DecodeFilter.java

@@ -27,7 +27,14 @@
     )
   },
   snippets = {
-    @JinjavaSnippet(code = "{% set my_number = -53 %}\n" + "{{ my_number|abs }}")
+    @JinjavaSnippet(
+      desc = "Decode a Base 64-encoded ASCII string into a UTF-8 string",
+      code = "{{ 'eydmb28nOiBbJ2JhciddfQ=='|b64decode }}"
+    ),
+    @JinjavaSnippet(
+      desc = "Decode a Base 64-encoded ASCII string into a UTF-16 Little Endian string",
+      code = "{{ 'Adg33A=='|b64decode(encoding='utf-16le') }}"
+    )
   }
 )
 public class Base64DecodeFilter implements Filter {

src/main/java/com/hubspot/jinjava/lib/filter/Base64EncodeFilter.java

@@ -20,7 +20,7 @@
   value = "Encode the string input into base 64.",
   input = @JinjavaParam(
     value = "input",
-    type = "string",
+    type = "object",
     desc = "The string input to encode into base 64.",
     required = true
   ),
@@ -33,7 +33,14 @@
     )
   },
   snippets = {
-    @JinjavaSnippet(code = "{% set my_number = -53 %}\n" + "{{ my_number|abs }}")
+    @JinjavaSnippet(
+      desc = "Encode a value with UTF-8 encoding into a Base 64 ASCII string",
+      code = "{{ 'abcd'|b64encode }}"
+    ),
+    @JinjavaSnippet(
+      desc = "Encode a value with UTF-16 Little Endian encoding into a Base 64 ASCII string",
+      code = "{{ '\uD801\uDC37'|b64encode(encoding='utf-16le') }}"
+    )
   }
 )
 public class Base64EncodeFilter implements Filter {

src/test/java/com/hubspot/jinjava/lib/filter/Base64FilterTest.java

@@ -20,20 +20,23 @@ public void itEncodesWithDefaultCharset() {
   @Test
   public void itEncodesWithUtf16Le() {
     assertThat(
-        jinjava.render("{{ 'ß'|b64encode(encoding='utf-16le') }}", Collections.emptyMap())
+        jinjava.render(
+          "{{ '\uD801\uDC37'|b64encode(encoding='utf-16le') }}",
+          Collections.emptyMap()
+        )
       )
-      .isEqualTo("3wA=");
+      .isEqualTo("Adg33A==");
   }
 
   @Test
   public void itDecodesWithUtf16Le() {
     assertThat(
         jinjava.render(
-          "{{ '3wA='|b64decode(encoding='utf-16le') }}",
+          "{{ 'Adg33A=='|b64decode(encoding='utf-16le') }}",
           Collections.emptyMap()
         )
       )
-      .isEqualTo("ß");
+      .isEqualTo("\uD801\uDC37");
   }
 
   @Test