Format multi-column ORDER BY and add tests

Introduce a FormattedScriptGenerator and OrderByCollector to improve formatting of multi-column ORDER BY clauses (split into indented, multi-line lists). Update SqlFormatter to reuse the new generator and produce the formatted script. Add three new command tests in Tests.cs (single, multiple, and multiple with DESC/ASC) and corresponding verified output files. Also update readme snippet anchor line numbers to match the new test locations.

Author: SimonCropp

readme.md

@@ -65,7 +65,7 @@ await Verify(connection)
     // include only tables and views
     .SchemaIncludes(DbObjects.Tables | DbObjects.Views);
 ```
-<sup><a href='/src/Tests/Tests.cs#L393-L399' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaInclude' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L423-L429' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaInclude' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Available values:
@@ -103,7 +103,7 @@ await Verify(connection)
         _ => _ is TableViewBase ||
              _.Name == "MyTrigger");
 ```
-<sup><a href='/src/Tests/Tests.cs#L418-L426' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaFilter' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L448-L456' title='Snippet source file'>snippet source</a> | <a href='#snippet-SchemaFilter' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -125,7 +125,7 @@ command.CommandText = "select Value from MyTable";
 var value = await command.ExecuteScalarAsync();
 await Verify(value!);
 ```
-<sup><a href='/src/Tests/Tests.cs#L202-L212' title='Snippet source file'>snippet source</a> | <a href='#snippet-Recording' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L232-L242' title='Snippet source file'>snippet source</a> | <a href='#snippet-Recording' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Will result in the following verified file:
@@ -180,7 +180,7 @@ await Verify(
         sqlEntries = entries
     });
 ```
-<sup><a href='/src/Tests/Tests.cs#L279-L309' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingSpecific' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L309-L339' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingSpecific' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -208,7 +208,7 @@ var sqlErrorsViaType = entries
     .Select(_ => _.Data)
     .OfType<ErrorEntry>();
 ```
-<sup><a href='/src/Tests/Tests.cs#L335-L354' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingReadingResults' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/Tests.cs#L365-L384' title='Snippet source file'>snippet source</a> | <a href='#snippet-RecordingReadingResults' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 

src/Tests/Tests.CommandOrderByMultipleColumns.verified.txt

@@ -0,0 +1,9 @@
+{
+  Text:
+select   Id,
+         Name
+from     MyTable
+order by Name,
+         Id,
+  HasTransaction: false
+}

src/Tests/Tests.CommandOrderByMultipleColumnsDesc.verified.txt

@@ -0,0 +1,9 @@
+{
+  Text:
+select   Id,
+         Name
+from     MyTable
+order by Name desc,
+         Id asc,
+  HasTransaction: false
+}

src/Tests/Tests.CommandOrderBySingleColumn.verified.txt

@@ -0,0 +1,7 @@
+{
+  Text:
+select   Value
+from     MyTable
+order by Value,
+  HasTransaction: false
+}

src/Tests/Tests.cs

@@ -164,6 +164,36 @@ public async Task CommandFull()
         await Verify(command);
     }
 
+    [Test]
+    public async Task CommandOrderBySingleColumn()
+    {
+        var command = new SqlCommand
+        {
+            CommandText = "select Value from MyTable order by Value"
+        };
+        await Verify(command);
+    }
+
+    [Test]
+    public async Task CommandOrderByMultipleColumns()
+    {
+        var command = new SqlCommand
+        {
+            CommandText = "select Id, Name from MyTable order by Name, Id"
+        };
+        await Verify(command);
+    }
+
+    [Test]
+    public async Task CommandOrderByMultipleColumnsDesc()
+    {
+        var command = new SqlCommand
+        {
+            CommandText = "select Id, Name from MyTable order by Name desc, Id asc"
+        };
+        await Verify(command);
+    }
+
     [Test]
     public async Task Exception()
     {

src/Verify.SqlServer/FormattedScriptGenerator.cs

@@ -0,0 +1,55 @@
+class FormattedScriptGenerator
+{
+    readonly Sql170ScriptGenerator generator = new(
+        new()
+        {
+            SqlVersion = SqlVersion.Sql170,
+            KeywordCasing = KeywordCasing.Lowercase,
+            IndentationSize = 2,
+            AlignClauseBodies = true
+        });
+
+    public string GenerateScript(TSqlFragment fragment)
+    {
+        generator.GenerateScript(fragment, out var script);
+
+        var collector = new OrderByCollector();
+        fragment.Accept(collector);
+
+        foreach (var orderBy in collector.Clauses)
+        {
+            if (orderBy.OrderByElements.Count <= 1)
+            {
+                continue;
+            }
+
+            var elements = new List<string>(orderBy.OrderByElements.Count);
+            foreach (var element in orderBy.OrderByElements)
+            {
+                generator.GenerateScript(element, out var text);
+                elements.Add(text);
+            }
+
+            var singleLine = "order by " + string.Join(", ", elements);
+
+            var pos = script.IndexOf(singleLine, StringComparison.Ordinal);
+            if (pos == -1)
+            {
+                continue;
+            }
+
+            var lineStart = script.LastIndexOf('\n', pos) + 1;
+            var indent = new string(' ', pos - lineStart + "order by ".Length);
+
+            var multiLine = "order by " + string.Join(",\n" + indent, elements);
+
+#if NET48
+            script = script.Substring(0, pos) + multiLine + script.Substring(pos + singleLine.Length);
+#else
+            script = string.Concat(script.AsSpan(0, pos), multiLine, script.AsSpan(pos + singleLine.Length));
+#endif
+        }
+
+        return script;
+    }
+}

src/Verify.SqlServer/OrderByCollector.cs

@@ -0,0 +1,7 @@
+class OrderByCollector : TSqlFragmentVisitor
+{
+    public List<OrderByClause> Clauses { get; } = [];
+
+    public override void Visit(OrderByClause node) =>
+        Clauses.Add(node);
+}

src/Verify.SqlServer/SqlFormatter.cs

@@ -1,5 +1,7 @@
 static class SqlFormatter
 {
+    static readonly FormattedScriptGenerator generator = new();
+
     public static StringBuilder Format(string input)
     {
         var parser = new TSql170Parser(false);
@@ -23,24 +25,12 @@ Failed to parse sql.
         var visitor = new RemoveSquareBracketVisitor();
         fragment.Accept(visitor);
 
-        var generator = new Sql170ScriptGenerator(
-            new()
-            {
-                SqlVersion = SqlVersion.Sql170,
-                KeywordCasing = KeywordCasing.Lowercase,
-                IndentationSize = 2,
-                AlignClauseBodies = true
-            });
-
-        var builder = new StringBuilder();
-        using (var writer = new StringWriter(builder, CultureInfo.InvariantCulture))
-        {
-            generator.GenerateScript(fragment, writer);
-        }
+        var script = generator.GenerateScript(fragment);
 
+        var builder = new StringBuilder(script);
         builder.TrimEnd();
         // ReSharper disable once UseIndexFromEndExpression
-        if (builder[builder.Length -1] == ';')
+        if (builder[builder.Length - 1] == ';')
         {
             builder.Length--;
         }