Improve support for roundtrip comments with model

xoofx · Jan 24, 2022 · 014e186 · 014e186
1 parent 78b028b
commit 014e186
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Showing 2 changed files with 34 additions and 5 deletions.
diff --git a/src/Tomlyn.Tests/ModelTests/ReflectionModelTests.cs b/src/Tomlyn.Tests/ModelTests/ReflectionModelTests.cs
@@ -172,6 +172,32 @@ public void TestReflectionModelWithErrors()
             StringAssert.Contains("id3", diag.Message);
         }
 
+        [Test]
+        public void TestCommentRoundtripWithModel()
+        {
+            var input = @"
+# This is comment before
+name = 1 # This is a comment
+
+# This is a comment before a table
+[table] # a comment after an table
+key = 1
+
+# A Comment before a table array
+[[array]] # a comment after a table array
+key2 = 3
+# This is a comment after a key
+";
+            StandardTests.DisplayHeader("input");
+            Console.WriteLine(input);
+            var model = Toml.ToModel(input);
+            var toml2 = Toml.FromModel(model);
+            StandardTests.DisplayHeader("toml - write back");
+            Console.WriteLine(toml2);
+
+            Assert.AreEqual(input, toml2);
+        }
+
         public class SimpleModel
         {
             public SimpleModel()

diff --git a/src/Tomlyn/Model/ModelToTomlTransform.cs b/src/Tomlyn/Model/ModelToTomlTransform.cs
@@ -220,8 +220,11 @@ private bool VisitObject(ObjectDynamicAccessor accessor, object currentObject, b
                     WriteLeadingTrivia(name);
                 }
 
-                WriteKeyValue(name, prop.Value, propToInline);
-                if (!inline)
+                var valueAccessor = WriteKeyValue(name, prop.Value, propToInline);
+
+                // Special case to not output duplicated new lines that were already handled
+                // WriteKeyValue
+                if (!inline && (valueAccessor is PrimitiveDynamicAccessor || propToInline))
                 {
                     WriteTrailingTrivia(name);
                     _writer.WriteLine();
@@ -277,10 +280,8 @@ private void VisitList(ListDynamicAccessor accessor, object currentObject, bool
         }
     }
 
-    private void WriteKeyValue(string name, object? value, bool inline)
+    private DynamicAccessor WriteKeyValue(string name, object value, bool inline)
     {
-        if (value is null) return;
-
         var accessor = _context.GetAccessor(value.GetType());
 
         switch (accessor)
@@ -348,6 +349,8 @@ private void WriteKeyValue(string name, object? value, bool inline)
             default:
                 throw new ArgumentOutOfRangeException(nameof(accessor));
         }
+
+        return accessor;
     }
 
     private TomlPropertyDisplayKind GetDisplayKind(string name)