Fixed support for deserialization from Base64 into a byte array.

jackson-core/src/main/java/io/micronaut/jackson/core/tree/JsonNodeTraversingParser.java

@@ -257,6 +257,10 @@ public int getTextOffset() throws IOException {
 
     @Override
     public byte[] getBinaryValue(Base64Variant b64variant) throws IOException {
+        String text = getText();
+        if (text != null) {
+            return b64variant.decode(text);
+        }
         return null;
     }
 

jackson-core/src/test/groovy/io/micronaut/jackson/core/tree/JsonNodeTraversingParserTest.groovy

@@ -0,0 +1,28 @@
+package io.micronaut.jackson.core.tree
+
+import com.fasterxml.jackson.core.Base64Variant
+import com.fasterxml.jackson.core.Base64Variants
+import io.micronaut.json.tree.JsonNode
+import spock.lang.Specification
+
+class JsonNodeTraversingParserTest extends Specification {
+
+    def getBinaryValue() {
+        given:
+        def jsonNode = JsonNode.createArrayNode([JsonNode.createStringNode(content)])
+        def parser = new JsonNodeTraversingParser(jsonNode)
+
+        parser.nextToken()
+        parser.nextToken()
+
+        def binaryValue = parser.getBinaryValue(Base64Variants.MIME)
+
+        expect:
+        new String(binaryValue) == expected
+
+        where:
+        content || expected
+        "YWJj"  || "abc"
+    }
+
+}