Centralized some exception messaging, quality improvement.

Author: RyanLamansky

SqlServerSimulator/Parser/Expression.cs

@@ -34,14 +34,14 @@ public static Expression Parse(Simulation simulation, IEnumerator<Token> tokens,
                         {
                             case Keyword.As:
                                 if (expression is null || !tokens.TryMoveNext(out token) || token is not Name alias)
-                                    throw new SimulatedSqlException("Incorrect syntax near the keyword 'as'.", 156, 15, 1);
+                                    throw SimulatedSqlException.SyntaxErrorNear(name);
 
                                 expression = new NamedExpression(expression, alias.Value);
                                 _ = tokens.TryMoveNext(out token);
                                 return expression;
                             case Keyword.From:
                                 if (expression is null)
-                                    throw new SimulatedSqlException("Incorrect syntax near the keyword 'from'.", 156, 15, 1);
+                                    throw SimulatedSqlException.SyntaxErrorNear(name);
 
                                 return expression;
                         }

SqlServerSimulator/Parser/Selection.cs

@@ -30,7 +30,7 @@ public static Selection Parse(Simulation simulation, IEnumerator<Token> tokens,
                 case null: // "Select" with no "From".
                     return new(new(
                         columnIndexes,
-                        [[.. expressions.Select(x => x.Run(column => throw new SimulatedSqlException($"Invalid column name '{column}'.", 207, 16, 1)))]]
+                        [[.. expressions.Select(x => x.Run(column => throw SimulatedSqlException.InvalidColumnName(column)))]]
                         ));
 
                 case UnquotedString unquotedString:
@@ -41,7 +41,7 @@ public static Selection Parse(Simulation simulation, IEnumerator<Token> tokens,
                     {
                         case StringToken tableName:
                             if (!simulation.Tables.TryGetValue(tableName.Value, out var table) && !simulation.SystemTables.Value.TryGetValue(tableName.Value, out table))
-                                throw new SimulatedSqlException($"Invalid object name {tableName}.", 208, 16, 1);
+                                throw SimulatedSqlException.InvalidObjectName(tableName);
 
                             if (tokens.TryMoveNext(out token))
                             {
@@ -61,7 +61,7 @@ public static Selection Parse(Simulation simulation, IEnumerator<Token> tokens,
                                 table.Rows.Select<object?[], object?[]>(row => [..expressions.Select(x => x.Run(columnName =>
                                 {
                                     var columnIndex = table.Columns.FindIndex(column => Collation.Default.Equals(column.Name, columnName.Last()));
-                                    return columnIndex == -1 ? throw new SimulatedSqlException($"Invalid column name '{columnName}'.", 207, 16, 1) : row[columnIndex]; }))])));
+                                    return columnIndex == -1 ? throw SimulatedSqlException.InvalidColumnName(columnName) : row[columnIndex]; }))])));
                     }
 
                     throw new NotSupportedException($"Simulated selection processor expected a source table, found {token}.");

SqlServerSimulator/Parser/Tokens/Comma.cs

@@ -1,7 +1,6 @@
 namespace SqlServerSimulator.Parser.Tokens;
 
 sealed class Comma : Token
-#pragma warning restore
 {
     public override string ToString() => ",";
 }

SqlServerSimulator/SimulatedSqlException.cs

@@ -1,5 +1,5 @@
 using SqlServerSimulator.Parser;
-using System.Collections.Immutable;
+using SqlServerSimulator.Parser.Tokens;
 using System.Data.Common;
 using System.Globalization;
 
@@ -18,25 +18,25 @@ internal SimulatedSqlException(string? message)
     {
     }
 
-    internal SimulatedSqlException(string message, int number, byte @class, byte state)
+    private SimulatedSqlException(string message, int number, byte @class, byte state)
         : this(message, new SimulatedSqlError(message, number, @class, state))
     {
     }
 
-    internal SimulatedSqlException(string? message, params ReadOnlySpan<SimulatedSqlError> errors)
+    private SimulatedSqlException(string? message, params ReadOnlySpan<SimulatedSqlError> errors)
         : base(message ?? "Simulated exception with no message.")
     {
         base.HResult = unchecked((int)0x80131904);
         base.Source = "Core Microsoft SqlClient Data Provider";
 
         if (errors.Length == 0)
         {
-            this.Errors = ImmutableArray.Create([new SimulatedSqlError(base.Message, 0, 0, 0)]);
+            this.Errors = [new SimulatedSqlError(base.Message, 0, 0, 0)];
 
             return;
         }
 
-        this.Errors = ImmutableArray.Create(errors);
+        this.Errors = [.. errors];
 
         var firstError = errors[0];
 
@@ -84,5 +84,13 @@ internal SimulatedSqlException(string? message, params ReadOnlySpan<SimulatedSql
 
     public IReadOnlyList<SimulatedSqlError> Errors { get; }
 
+    internal static SimulatedSqlException InvalidColumnName(string name) => new($"Invalid column name '{name}'.", 207, 16, 1);
+
+    internal static SimulatedSqlException InvalidColumnName(IEnumerable<string> name) => InvalidColumnName(string.Join('.', name));
+
+    internal static SimulatedSqlException InvalidObjectName(StringToken name) => new($"Invalid object name {name}.", 208, 16, 1);
+
     internal static SimulatedSqlException SyntaxErrorNear(Token token) => new($"Incorrect syntax near '{token}'.", 102, 15, 1);
+
+    internal static SimulatedSqlException ThereIsAlreadyAnObject(string name) => new($"There is already an object named '{name}' in the database.", 2714, 16, 6);
 }

SqlServerSimulator/Simulation.cs

@@ -209,7 +209,7 @@ internal IEnumerable<SimulatedStatementOutcome> CreateResultSetsForCommand(Simul
                                                 break;
 
                                             if (!this.Tables.TryAdd(table.Name, table))
-                                                throw new SimulatedSqlException($"There is already an object named '{table.Name}' in the database.", 2714, 16, 6);
+                                                throw SimulatedSqlException.ThereIsAlreadyAnObject(table.Name);
 
                                             continue;
                                     }
@@ -229,7 +229,7 @@ internal IEnumerable<SimulatedStatementOutcome> CreateResultSetsForCommand(Simul
                                 break;
 
                             if (!this.Tables.TryGetValue(destinationTableToken.Value, out var destinationTable))
-                                throw new SimulatedSqlException($"Invalid object name '{destinationTableToken.Value}'.", 208, 16, 0);
+                                throw SimulatedSqlException.InvalidObjectName(destinationTableToken);
 
                             Column[] destinationColumns;
                             if ((token = tokens.RequireNext()) is OpenParentheses)
@@ -239,7 +239,7 @@ internal IEnumerable<SimulatedStatementOutcome> CreateResultSetsForCommand(Simul
                                 {
                                     var columnName = column.Value;
                                     var tableColumn = destinationTable.Columns.FirstOrDefault(c => Collation.Default.Equals(c.Name, columnName))
-                                        ?? throw new SimulatedSqlException($"Invalid column name '{columnName}'.", 207, 16, 1);
+                                        ?? throw SimulatedSqlException.InvalidColumnName(columnName);
                                     usedColumns.Add(tableColumn);
                                 }