Fix #163

release-notes/CREDITS-2.x

@@ -84,3 +84,7 @@ Vincent Boulaye (vboulaye@github)
 * Implemented #15: Add a `CsvParser.Feature.SKIP_EMPTY_LINES` to allow
   skipping empty rows
  (2.10.1)
+
+Piyush Kumar (piyushkumar13@github)
+* Reported #163: (yaml) `SequenceWriter` does not create multiple docs in a single yaml file
+ (2.10.2)

release-notes/VERSION-2.x

@@ -10,6 +10,8 @@ Modules:
 
 2.10.2 (not yet released)
 
+#163: (yaml) `SequenceWriter` does not create multiple docs in a single yaml file
+ (reported by Piyush K)
 #166: (csv) Incorrect `JsonParseException` Message for missing separator char
  (reported by gimiz@github)
 

yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLGenerator.java

@@ -216,6 +216,8 @@ private Feature(boolean defaultState) {
 
     protected DumperOptions _outputOptions;
 
+    protected final org.yaml.snakeyaml.DumperOptions.Version _docVersion;
+
     // for field names, leave out quotes
     private final static DumperOptions.ScalarStyle STYLE_UNQUOTED_NAME = DumperOptions.ScalarStyle.PLAIN;
 
@@ -252,6 +254,8 @@ private Feature(boolean defaultState) {
      */
     protected String _typeId;
 
+    protected int _rootValueCount;
+
     /*
     /**********************************************************
     /* Life-cycle
@@ -267,19 +271,14 @@ public YAMLGenerator(IOContext ctxt, int jsonFeatures, int yamlFeatures,
         _ioContext = ctxt;
         _formatFeatures = yamlFeatures;
         _writer = out;
+        _docVersion = version;
 
         _outputOptions = buildDumperOptions(jsonFeatures, yamlFeatures, version);
 
         _emitter = new Emitter(_writer, _outputOptions);
         // should we start output now, or try to defer?
-        _emitter.emit(new StreamStartEvent(null, null));
-        Map<String,String> noTags = Collections.emptyMap();
-
-        boolean startMarker = Feature.WRITE_DOC_START_MARKER.enabledIn(yamlFeatures);
-
-        _emitter.emit(new DocumentStartEvent(null, null, startMarker,
-                version, // for 1.10 was: ((version == null) ? null : version.getArray()),
-                noTags));
+        _emit(new StreamStartEvent(null, null));
+        _emitStartDocument();
     }
 
     protected DumperOptions buildDumperOptions(int jsonFeatures, int yamlFeatures,
@@ -479,8 +478,11 @@ public final void flush() throws IOException
     public void close() throws IOException
     {
         if (!isClosed()) {
-            _emitter.emit(new DocumentEndEvent(null, null, false));
-            _emitter.emit(new StreamEndEvent(null, null));
+            // 11-Dec-2019, tatu: Should perhaps check if content is to be auto-closed...
+            //   but need END_DOCUMENT regardless
+
+            _emitEndDocument();
+            _emit(new StreamEndEvent(null, null));
             super.close();
 
             /* 25-Nov-2008, tatus: As per [JACKSON-16] we are not to call close()
@@ -518,7 +520,7 @@ public final void writeStartArray() throws IOException
         if (anchor != null) {
             _objectId = null;
         }
-        _emitter.emit(new SequenceStartEvent(anchor, yamlTag,
+        _emit(new SequenceStartEvent(anchor, yamlTag,
                 implicit,  null, null, style));
     }
 
@@ -531,7 +533,7 @@ public final void writeEndArray() throws IOException
         // just to make sure we don't "leak" type ids
         _typeId = null;
         _writeContext = _writeContext.getParent();
-        _emitter.emit(new SequenceEndEvent(null, null));
+        _emit(new SequenceEndEvent(null, null));
     }
 
     @Override
@@ -546,7 +548,7 @@ public final void writeStartObject() throws IOException
         if (anchor != null) {
             _objectId = null;
         }
-        _emitter.emit(new MappingStartEvent(anchor, yamlTag,
+        _emit(new MappingStartEvent(anchor, yamlTag,
                 implicit, null, null, style));
     }
 
@@ -559,7 +561,7 @@ public final void writeEndObject() throws IOException
         // just to make sure we don't "leak" type ids
         _typeId = null;
         _writeContext = _writeContext.getParent();
-        _emitter.emit(new MappingEndEvent(null, null));
+        _emit(new MappingEndEvent(null, null));
     }
 
     /*
@@ -815,7 +817,7 @@ public void writeObjectRef(Object id)
     {
         _verifyValueWrite("write Object reference");
         AliasEvent evt = new AliasEvent(String.valueOf(id), null, null);
-        _emitter.emit(evt);
+        _emit(evt);
     }
 
     @Override
@@ -840,6 +842,15 @@ protected final void _verifyValueWrite(String typeMsg)
         if (status == JsonWriteContext.STATUS_EXPECT_NAME) {
             _reportError("Can not "+typeMsg+", expecting field name");
         }
+        if (_writeContext.inRoot()) {
+            // Start-doc emitted when creating generator, but otherwise need it; similarly,
+            // need matching end-document to close earlier open one
+            if (_writeContext.getCurrentIndex() > 0) {
+                _emitEndDocument();
+                _emitStartDocument();
+            }
+        }
+
     }
 
     @Override
@@ -861,7 +872,7 @@ protected void _releaseBuffers() {
 
     protected void _writeScalar(String value, String type, DumperOptions.ScalarStyle style) throws IOException
     {
-        _emitter.emit(_scalarEvent(value, style));
+        _emit(_scalarEvent(value, style));
     }
 
     private void _writeScalarBinary(Base64Variant b64variant,
@@ -874,7 +885,7 @@ private void _writeScalarBinary(Base64Variant b64variant,
         }
         final String lf = _lf();
         String encoded = _base64encode(b64variant, data, lf);
-        _emitter.emit(new ScalarEvent(null, TAG_BINARY, EXPLICIT_TAGS, encoded,
+        _emit(new ScalarEvent(null, TAG_BINARY, EXPLICIT_TAGS, encoded,
                 null, null, STYLE_BASE64));
     }
 
@@ -976,4 +987,24 @@ private boolean _valueNeedsQuoting(String name) {
     protected String _lf() {
         return _outputOptions.getLineBreak().getString();
     }
+
+    // @since 2.10.2
+    protected void _emitStartDocument() throws IOException
+    {
+        Map<String,String> noTags = Collections.emptyMap();
+        boolean startMarker = Feature.WRITE_DOC_START_MARKER.enabledIn(_formatFeatures);
+        _emit(new DocumentStartEvent(null, null, startMarker,
+                _docVersion, // for 1.10 was: ((version == null) ? null : version.getArray()),
+                noTags));
+    }
+
+    // @since 2.10.2
+    protected void _emitEndDocument() throws IOException {
+        _emit(new DocumentEndEvent(null, null, false));
+    }
+
+    // @since 2.10.2
+    protected final void _emit(Event e) throws IOException {
+        _emitter.emit(e);
+    }
 }

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/failing/MultipleDocumentsWriteTest.java → yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/MultipleDocumentsWriteTest.java

@@ -1,12 +1,11 @@
-package com.fasterxml.jackson.dataformat.yaml.failing;
+package com.fasterxml.jackson.dataformat.yaml;
 
 import java.io.StringWriter;
+import java.util.Arrays;
 import java.util.Collections;
 
 import com.fasterxml.jackson.databind.*;
 
-import com.fasterxml.jackson.dataformat.yaml.ModuleTestBase;
-
 // for [dataformats-text#163]
 public class MultipleDocumentsWriteTest extends ModuleTestBase
 {
@@ -26,25 +25,21 @@ public void testWriteMultipleDocsBeans() throws Exception
         }
         w.close();
 
-        String yaml = w.toString();
-
-        // !!! TODO: actual expected multi-doc contents:
-        assertEquals("foo", yaml);
+        String yaml = w.toString().trim();
+        assertEquals("---\nvalue: 42\n---\nvalue: 28", yaml);
     }
 
     public void testWriteMultipleDocsLists() throws Exception
     {
         ObjectMapper mapper = newObjectMapper();
         StringWriter w = new StringWriter();
         try (SequenceWriter seqW = mapper.writer().writeValues(w)) {
-            seqW.write(Collections.singleton(42));
+            seqW.write(Arrays.asList(28,12));
             seqW.write(Collections.singleton(28));
         }
         w.close();
 
-        String yaml = w.toString();
-
-        // !!! TODO: actual expected multi-doc contents:
-        assertEquals("foo", yaml);
+        String yaml = w.toString().trim();
+        assertEquals("---\n- 28\n- 12\n---\n- 28", yaml);
     }
 }

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/deser/DatabindReadTest.java

@@ -116,7 +116,6 @@ public void testUUIDs() throws Exception
     {
         UUID uuid = new UUID(0, 0);
         String yaml = MAPPER.writeValueAsString(uuid);
-
         UUID result = MAPPER.readValue(yaml, UUID.class);
 
         assertEquals(uuid, result);