Fixed #140

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -8,6 +8,10 @@ Modules:
 === Releases ===
 ------------------------------------------------------------------------
 
+2.10.0.pr2 (not yet released)
+
+#140: (yaml) Implement `JsonGenerator.writeFieldId(...)` for `YAMLGenerator`
+
 2.10.0.pr1 (19-Jul-2019)
 
 #50: (yaml) Empty string serialized without quotes if MINIMIZE_QUOTES is enabled

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

@@ -443,6 +443,18 @@ public final void writeFieldName(SerializableString name)
         _writeFieldName(name.getValue());
     }
 
+    @Override // override since 2.10 (method added in 2.8)
+    public void writeFieldId(long id) throws IOException {
+        // 24-Jul-2019, tatu: Should not force construction of a String here...
+        String idStr = Long.valueOf(id).toString(); // since instances for small values cached
+        if (_writeContext.writeFieldName(idStr) == JsonWriteContext.STATUS_EXPECT_VALUE) {
+            _reportError("Can not write a field id, expecting a value");
+        }
+        // to avoid quoting
+//        _writeFieldName(idStr);
+        _writeScalar(idStr, "int", STYLE_SCALAR);
+    }
+
     @Override
     public final void writeStringField(String fieldName, String value)
         throws IOException

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/ser/GeneratorWithMinimizeTest.java

@@ -1,16 +1,19 @@
 package com.fasterxml.jackson.dataformat.yaml.ser;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.*;
 
 public class GeneratorWithMinimizeTest extends ModuleTestBase
 {
-    private final static YAMLMapper MINIM_MAPPER = new YAMLMapper();
-    static {
-        MINIM_MAPPER.enable(YAMLGenerator.Feature.MINIMIZE_QUOTES);
-    }
+    private final ObjectMapper VANILLA_MAPPER = newObjectMapper();
+
+    private final YAMLMapper MINIM_MAPPER = YAMLMapper.builder()
+            .enable(YAMLGenerator.Feature.MINIMIZE_QUOTES)
+            .build();
 
     public void testDefaultSetting() {
         YAMLFactory f = new YAMLFactory();
@@ -165,4 +168,31 @@ public void testEmptyStringWithMinimizeQuotes() throws Exception
 
         assertEquals("---\nkey: \"\"", yaml);
     }
+
+    // [dataformats-text#140]
+    public void testNumberKey() throws Exception
+    {
+        // First, test with Strings that happen to look like Integer
+        final Map<String, String> stringKeyMap = Collections.singletonMap(
+                "42", "answer");
+        // Quoted in both cases
+        assertEquals("---\n\"42\": \"answer\"",
+                VANILLA_MAPPER.writeValueAsString(stringKeyMap).trim());
+        // but not if minimizing quotes
+        assertEquals("---\n\"42\": answer",
+                MINIM_MAPPER.writeValueAsString(stringKeyMap).trim());
+
+        // And then true Integer keys
+        
+        final Map<Integer, String> intKeyMap = Collections.singletonMap(
+                Integer.valueOf(42), "answer");
+
+        // by default, is quoted
+        assertEquals("---\n42: \"answer\"",
+                VANILLA_MAPPER.writeValueAsString(intKeyMap).trim());
+
+        // but not if minimizing quotes
+        assertEquals("---\n42: answer",
+                MINIM_MAPPER.writeValueAsString(intKeyMap).trim());
+    }
 }