Emit the correct Alias on the key (#908) (#929)

src/emitter.cpp

@@ -504,6 +504,9 @@ void Emitter::FlowMapPrepareSimpleKeyValue(EmitterNodeType::value child) {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(lastIndent);
+    if (m_pState->HasAlias()) {
+      m_stream << " ";
+    }
     m_stream << ":";
   }
 
@@ -643,6 +646,9 @@ void Emitter::BlockMapPrepareSimpleKeyValue(EmitterNodeType::value child) {
   const std::size_t nextIndent = curIndent + m_pState->CurGroupIndent();
 
   if (!m_pState->HasBegunNode()) {
+    if (m_pState->HasAlias()) {
+      m_stream << " ";
+    }
     m_stream << ":";
   }
 
@@ -864,6 +870,8 @@ Emitter& Emitter::Write(const _Alias& alias) {
 
   StartedScalar();
 
+  m_pState->SetAlias();
+
   return *this;
 }
 

src/emitterstate.cpp

@@ -29,6 +29,7 @@ EmitterState::EmitterState()
       m_groups{},
       m_curIndent(0),
       m_hasAnchor(false),
+      m_hasAlias(false),
       m_hasTag(false),
       m_hasNonContent(false),
       m_docCount(0) {}
@@ -53,6 +54,8 @@ void EmitterState::SetLocalValue(EMITTER_MANIP value) {
 
 void EmitterState::SetAnchor() { m_hasAnchor = true; }
 
+void EmitterState::SetAlias() { m_hasAlias = true; }
+
 void EmitterState::SetTag() { m_hasTag = true; }
 
 void EmitterState::SetNonContent() { m_hasNonContent = true; }
@@ -87,6 +90,7 @@ void EmitterState::StartedNode() {
   }
 
   m_hasAnchor = false;
+  m_hasAlias = false;
   m_hasTag = false;
   m_hasNonContent = false;
 }

src/emitterstate.h

@@ -43,6 +43,7 @@ class EmitterState {
 
   // node handling
   void SetAnchor();
+  void SetAlias();
   void SetTag();
   void SetNonContent();
   void SetLongKey();
@@ -65,6 +66,7 @@ class EmitterState {
   std::size_t LastIndent() const;
   std::size_t CurIndent() const { return m_curIndent; }
   bool HasAnchor() const { return m_hasAnchor; }
+  bool HasAlias() const { return m_hasAlias; }
   bool HasTag() const { return m_hasTag; }
   bool HasBegunNode() const {
     return m_hasAnchor || m_hasTag || m_hasNonContent;
@@ -187,6 +189,7 @@ class EmitterState {
   std::vector<std::unique_ptr<Group>> m_groups;
   std::size_t m_curIndent;
   bool m_hasAnchor;
+  bool m_hasAlias;
   bool m_hasTag;
   bool m_hasNonContent;
   std::size_t m_docCount;

test/integration/emitter_test.cpp

@@ -430,6 +430,21 @@ TEST_F(EmitterTest, AliasAndAnchor) {
   ExpectEmit("- &fred\n  name: Fred\n  age: 42\n- *fred");
 }
 
+TEST_F(EmitterTest, AliasOnKey) {
+  out << BeginSeq;
+  out << Anchor("name") << "Name";
+  out << BeginMap;
+  out << Key << Alias("name") << Value << "Fred";
+  out << EndMap;
+  out << Flow << BeginMap;
+  out << Key << Alias("name") << Value << "Mike";
+  out << EndMap;
+  out << EndSeq;
+  ExpectEmit(R"(- &name Name
+- *name : Fred
+- {*name : Mike})");
+}
+
 TEST_F(EmitterTest, AliasAndAnchorWithNull) {
   out << BeginSeq;
   out << Anchor("fred") << Null;