fix(bun): ignore scanonly columns in ExcludeColumn

Bun's ExcludeColumn errors with "can't find column" for scanonly fields
because they are not in the table's writable fields. Filter the exclude
list to writable bun fields so models with scanonly buffers can insert
and update again. Add tests for the adapter and reflection.

pkg/common/adapters/database/bun.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/uptrace/bun"
+	"github.com/uptrace/bun/schema"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
 	"github.com/bitechdev/ResolveSpec/pkg/dbtrace"
@@ -1507,8 +1508,30 @@ func (b *BunInsertQuery) OnConflict(action string) common.InsertQuery {
 	return b
 }
 
+// bunWritableExcludes drops columns bun already leaves out of INSERT/UPDATE
+// (scanonly fields) or does not know, since bun's ExcludeColumn errors with
+// "can't find column" for anything that is not in the table's writable fields.
+func bunWritableExcludes(model bun.Model, columns []string) []string {
+	tm, ok := model.(interface{ Table() *schema.Table })
+	if !ok || tm.Table() == nil {
+		return columns
+	}
+	table := tm.Table()
+	writable := make(map[string]struct{}, len(table.Fields))
+	for _, f := range table.Fields {
+		writable[f.Name] = struct{}{}
+	}
+	out := make([]string, 0, len(columns))
+	for _, c := range columns {
+		if _, ok := writable[c]; ok || c == "*" {
+			out = append(out, c)
+		}
+	}
+	return out
+}
+
 func (b *BunInsertQuery) ExcludeColumn(columns ...string) common.InsertQuery {
-	if len(columns) > 0 {
+	if columns = bunWritableExcludes(b.query.GetModel(), columns); len(columns) > 0 {
 		b.query = b.query.ExcludeColumn(columns...)
 	}
 	return b
@@ -1627,7 +1650,7 @@ func (b *BunUpdateQuery) SetMap(values map[string]interface{}) common.UpdateQuer
 }
 
 func (b *BunUpdateQuery) ExcludeColumn(columns ...string) common.UpdateQuery {
-	if len(columns) > 0 {
+	if columns = bunWritableExcludes(b.query.GetModel(), columns); len(columns) > 0 {
 		b.query = b.query.ExcludeColumn(columns...)
 	}
 	return b

pkg/common/adapters/database/bun_exclude_test.go

@@ -0,0 +1,100 @@
+package database
+
+import (
+	"database/sql"
+	"strings"
+	"testing"
+
+	"github.com/uptrace/bun"
+	"github.com/uptrace/bun/dialect/pgdialect"
+
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
+)
+
+// adhocBuffer mirrors the real-world DBAdhocBuffer: scanonly fields with both
+// bun and gorm read-only tags.
+type adhocBuffer struct {
+	CQL1        string `json:"cql1,omitempty" gorm:"->" bun:",scanonly"`
+	CQL2        string `json:"cql2,omitempty" gorm:"->" bun:",scanonly"`
+	RowNumber   int64  `json:"_rownumber,omitempty" gorm:"-" bun:",scanonly"`
+	RecordError string `json:"_error,omitempty" gorm:"-" bun:",scanonly"`
+}
+
+type excludeModel struct {
+	bun.BaseModel `bun:"table:public.crmnote,alias:crmnote"`
+	ID            int    `json:"id" bun:"id,pk"`
+	Note          string `json:"note" bun:"note,type:citext,"`
+	Norm          string `json:"norm" bun:"norm,generated"`
+
+	adhocBuffer `json:",omitempty" bun:",scanonly"`
+}
+
+func newExcludeDB() *bun.DB {
+	return bun.NewDB(&sql.DB{}, pgdialect.New())
+}
+
+// TestBunExcludeColumnWithNonWritableColumns feeds the reflection output
+// straight into the adapter, as the handlers do, for insert and update.
+func TestBunExcludeColumnWithNonWritableColumns(t *testing.T) {
+	db := newExcludeDB()
+	m := &excludeModel{}
+	cols := reflection.NonWritableColumns(m)
+	if len(cols) == 0 {
+		t.Fatal("expected non-writable columns")
+	}
+
+	ins := &BunInsertQuery{query: db.NewInsert().Model(m)}
+	ins.ExcludeColumn(cols...)
+	insSQL, err := ins.query.AppendQuery(db.QueryGen(), nil)
+	if err != nil {
+		t.Fatalf("insert: %v", err)
+	}
+
+	upd := &BunUpdateQuery{query: db.NewUpdate().Model(m).Where("id = 1")}
+	upd.ExcludeColumn(cols...)
+	updSQL, err := upd.query.AppendQuery(db.QueryGen(), nil)
+	if err != nil {
+		t.Fatalf("update: %v", err)
+	}
+
+	for name, q := range map[string]string{"insert": string(insSQL), "update": string(updSQL)} {
+		for _, bad := range []string{"cql1", "cql2", "_rownumber", "_error", "norm"} {
+			if strings.Contains(q, `"`+bad+`"`) {
+				t.Errorf("%s writes non-writable column %s: %s", name, bad, q)
+			}
+		}
+		if !strings.Contains(q, `"note"`) {
+			t.Errorf("%s dropped writable column note: %s", name, q)
+		}
+	}
+}
+
+func TestBunExcludeColumnIgnoresUnknownAndKeepsWritable(t *testing.T) {
+	db := newExcludeDB()
+	m := &excludeModel{}
+
+	ins := &BunInsertQuery{query: db.NewInsert().Model(m)}
+	ins.ExcludeColumn("does_not_exist", "note")
+	q, err := ins.query.AppendQuery(db.QueryGen(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(string(q), `"note"`) {
+		t.Errorf("writable column note should have been excluded: %s", q)
+	}
+}
+
+func TestBunExcludeColumnOnlyNonWritable(t *testing.T) {
+	db := newExcludeDB()
+	ins := &BunInsertQuery{query: db.NewInsert().Model(&excludeModel{})}
+	ins.ExcludeColumn("cql1") // everything filtered out: must not error or panic
+	if _, err := ins.query.AppendQuery(db.QueryGen(), nil); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestBunExcludeColumnWithoutModel(t *testing.T) {
+	db := newExcludeDB()
+	ins := &BunInsertQuery{query: db.NewInsert()}
+	ins.ExcludeColumn("cql1") // no model yet: must not panic
+}