Create GeneratorInitializer315Test.java

Author: pjfanning

src/test/java/tools/jackson/dataformat/xml/ser/GeneratorInitializer315Test.java

@@ -0,0 +1,35 @@
+package tools.jackson.dataformat.xml.ser;
+
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamWriter;
+
+import tools.jackson.databind.cfg.GeneratorInitializer;
+import tools.jackson.dataformat.xml.XmlMapper;
+import tools.jackson.dataformat.xml.XmlTestUtil;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+// [dataformat-xml#315]: allow custom encoding in XML declaration via GeneratorInitializer
+public class GeneratorInitializer315Test extends XmlTestUtil
+{
+    @Test
+    public void testCustomEncodingViaGeneratorInitializer() throws Exception {
+        GeneratorInitializer initializer = (config, gen) -> {
+            ToXmlGenerator xmlGen = (ToXmlGenerator) gen;
+            XMLStreamWriter sw = xmlGen.getStaxWriter();
+            try {
+                sw.writeStartDocument("ISO-8859-1", "1.0");
+            } catch (XMLStreamException e) {
+                throw new RuntimeException("Failed to write StartDocument event", e);
+            }
+        };
+        XmlMapper mapper = XmlMapper.builder()
+                .generatorInitializer(initializer)
+                .build();
+        String xml = mapper.writeValueAsString(new StringBean("test"));
+        assertTrue(xml.contains("encoding='ISO-8859-1'") || xml.contains("encoding=\"ISO-8859-1\""),
+                "Expected ISO-8859-1 encoding in XML declaration, got: " + xml);
+    }
+}