... and add a field name validator

SchemaValidator/SchemaValidator.cs

@@ -36,6 +36,7 @@ public class SchemaValidator
 			new ColumnCountValidator(gameData),
 			new IconTypeValidator(gameData),
 			new NamedInnerNamedOuterValidator(gameData),
+			new FieldNameValidator(gameData),
 			new ModelIdTypeValidator(gameData),
 			new ColorTypeValidator(gameData),
 			new IconPathExistsValidator(gameData),

SchemaValidator/Validation/Validators/FieldNameValidator.cs

@@ -0,0 +1,43 @@
+using System.Text.RegularExpressions;
+using Lumina;
+using Lumina.Data.Files.Excel;
+using SchemaValidator.New;
+using SchemaValidator.Util;
+
+namespace SchemaValidator.Validation.Validators;
+
+public partial class FieldNameValidator : Validator
+{
+	public override string ValidatorName() => "FieldNameValidator";
+	private string _sheetName = "";
+	
+	[GeneratedRegex("^[a-zA-Z_][a-zA-Z0-9_]*$", RegexOptions.Compiled)]
+	private static partial Regex _nameRegex();
+
+	public override ValidationResults Validate(ExcelHeaderFile exh, Sheet sheet)
+	{
+		_sheetName = sheet.Name;
+		
+		// I just don't have the brainpower to recurse right now
+		var flat = SchemaUtil.Flatten(exh, sheet);
+		
+		var results = new ValidationResults();
+		foreach (var fieldName in flat.Select(d => d.Field.Name).Distinct())
+		{
+			if (string.IsNullOrEmpty(fieldName))
+			{
+				results.Add(ValidationResult.Error(_sheetName, ValidatorName(), "Field name is empty."));
+				continue;
+			}
+
+			if (!_nameRegex().IsMatch(fieldName))
+				results.Results.Add(ValidationResult.Error(_sheetName, ValidatorName(), $"Field name {fieldName} is not a valid name."));
+		}
+		
+		if (results.Results.Count == 0)
+			return ValidationResults.Success(sheet.Name, ValidatorName());
+		return results;
+	}
+	
+	public FieldNameValidator(GameData gameData) : base(gameData) { }
+}