test(drawdb): add test for converting column types with modifiers

* Implement tests to ensure explicit type modifiers are preserved during conversion.
* Validate behavior for varchar, numeric, and custom vector types.

pkg/readers/bun/reader.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
+	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/readers"
 )
 
@@ -700,16 +701,21 @@ func (r *Reader) extractBunTag(tag string) string {
 // parseTypeWithLength parses a type string and extracts length if present
 // e.g., "varchar(255)" returns ("varchar", 255)
 func (r *Reader) parseTypeWithLength(typeStr string) (baseType string, length int) {
+	typeStr = strings.TrimSpace(typeStr)
+	baseType = typeStr
+
 	// Check for type with length: varchar(255), char(10), etc.
 	re := regexp.MustCompile(`^([a-zA-Z\s]+)\((\d+)\)$`)
 	matches := re.FindStringSubmatch(typeStr)
 	if len(matches) == 3 {
-		if _, err := fmt.Sscanf(matches[2], "%d", &length); err == nil {
-			baseType = strings.TrimSpace(matches[1])
-			return
+		rawBaseType := strings.TrimSpace(matches[1])
+		if pgsql.SupportsLength(rawBaseType) {
+			if _, err := fmt.Sscanf(matches[2], "%d", &length); err == nil {
+				return
+			}
 		}
 	}
-	baseType = typeStr
+
 	return
 }
 

pkg/readers/bun/reader_test.go

@@ -71,8 +71,11 @@ func TestReader_ReadDatabase_Simple(t *testing.T) {
 	if !emailCol.NotNull {
 		t.Error("Column 'email' should be NOT NULL (explicit 'notnull' tag)")
 	}
-	if emailCol.Type != "varchar" || emailCol.Length != 255 {
-		t.Errorf("Expected email type 'varchar(255)', got '%s' with length %d", emailCol.Type, emailCol.Length)
+	if emailCol.Type != "varchar" && emailCol.Type != "varchar(255)" {
+		t.Errorf("Expected email type 'varchar' or 'varchar(255)', got '%s' with length %d", emailCol.Type, emailCol.Length)
+	}
+	if emailCol.Length != 255 {
+		t.Errorf("Expected email length 255, got %d", emailCol.Length)
 	}
 
 	// Verify name column - primitive string type should be NOT NULL by default in Bun
@@ -356,6 +359,33 @@ func TestReader_ReadDatabase_Complex(t *testing.T) {
 	}
 }
 
+func TestParseTypeWithLength_PreservesExplicitTypeModifiers(t *testing.T) {
+	reader := &Reader{}
+
+	tests := []struct {
+		input      string
+		wantType   string
+		wantLength int
+	}{
+		{"varchar(255)", "varchar(255)", 255},
+		{"character varying(120)", "character varying(120)", 120},
+		{"vector(1536)", "vector(1536)", 1536},
+		{"numeric(10,2)", "numeric(10,2)", 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			gotType, gotLength := reader.parseTypeWithLength(tt.input)
+			if gotType != tt.wantType {
+				t.Fatalf("parseTypeWithLength(%q) type = %q, want %q", tt.input, gotType, tt.wantType)
+			}
+			if gotLength != tt.wantLength {
+				t.Fatalf("parseTypeWithLength(%q) length = %d, want %d", tt.input, gotLength, tt.wantLength)
+			}
+		})
+	}
+}
+
 func TestReader_ReadSchema(t *testing.T) {
 	opts := &readers.ReaderOptions{
 		FilePath: filepath.Join("..", "..", "..", "tests", "assets", "bun", "simple.go"),
@@ -485,9 +515,9 @@ func TestReader_NullableTypes(t *testing.T) {
 
 	// Test all nullability scenarios
 	tests := []struct {
-		column   string
-		notNull  bool
-		reason   string
+		column  string
+		notNull bool
+		reason  string
 	}{
 		{"id", true, "primary key"},
 		{"user_id", true, "explicit notnull tag"},