feat: setError on attempt to set non-positive .Varchar()

internal/dbtest/query_test.go

@@ -982,6 +982,10 @@ func TestQuery(t *testing.T) {
 			// Set default VARCHAR length to 10
 			return db.NewCreateTable().Model((*Model)(nil)).Varchar(10)
 		},
+		func(db *bun.DB) schema.QueryAppender {
+			// Non-positive VARCHAR length is illegal
+			return db.NewCreateTable().Model((*Model)(nil)).Varchar(-20)
+		},
 	}
 
 	timeRE := regexp.MustCompile(`'2\d{3}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}(\.\d+)?(\+\d{2}:\d{2})?'`)

internal/dbtest/testdata/snapshots/TestQuery-mariadb-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-mysql5-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-mysql8-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-pg-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-pgx-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

internal/dbtest/testdata/snapshots/TestQuery-sqlite-157

@@ -0,0 +1 @@
+bun: illegal VARCHAR length: -20

query_table_create.go

@@ -3,6 +3,7 @@ package bun
 import (
 	"context"
 	"database/sql"
+	"fmt"
 	"sort"
 	"strconv"
 	"strings"
@@ -18,12 +19,12 @@ type CreateTableQuery struct {
 
 	temp        bool
 	ifNotExists bool
-	
+
 	// varchar changes the default length for VARCHAR columns.
 	// Because some dialects require that length is always specified for VARCHAR type,
 	// we will use the exact user-defined type if length is set explicitly, as in `bun:",type:varchar(5)"`,
 	// but assume the new default length when it's omitted, e.g. `bun:",type:varchar"`.
-	varchar     int
+	varchar int
 
 	fks         []schema.QueryWithArgs
 	partitionBy schema.QueryWithArgs
@@ -91,6 +92,9 @@ func (q *CreateTableQuery) IfNotExists() *CreateTableQuery {
 
 // Varchar sets default length for VARCHAR columns.
 func (q *CreateTableQuery) Varchar(n int) *CreateTableQuery {
+	if n <= 0 {
+		q.setErr(fmt.Errorf("bun: illegal VARCHAR length: %d", n))
+	}
 	q.varchar = n
 	return q
 }