fix(pgdialect): postgres syntax errors for slices of pointers and json arrays #877

Author: rfarrjr

dialect/pgdialect/array.go

@@ -149,6 +149,8 @@ func (d *Dialect) arrayElemAppender(typ reflect.Type) schema.AppenderFunc {
 		if typ.Elem().Kind() == reflect.Uint8 {
 			return appendBytesElemValue
 		}
+	case reflect.Ptr:
+		return schema.PtrAppender(d.arrayElemAppender(typ.Elem()))
 	}
 	return schema.Appender(d, typ)
 }

dialect/pgdialect/array_parser.go

@@ -11,15 +11,18 @@ type arrayParser struct {
 
 	elem []byte
 	err  error
+
+	isJson bool
 }
 
 func newArrayParser(b []byte) *arrayParser {
 	p := new(arrayParser)
 
-	if len(b) < 2 || b[0] != '{' || b[len(b)-1] != '}' {
+	if len(b) < 2 || (b[0] != '{' && b[0] != '[') || (b[len(b)-1] != '}' && b[len(b)-1] != ']') {
 		p.err = fmt.Errorf("pgdialect: can't parse array: %q", b)
 		return p
 	}
+	p.isJson = b[0] == '['
 
 	p.p.Reset(b[1 : len(b)-1])
 	return p
@@ -51,7 +54,7 @@ func (p *arrayParser) readNext() error {
 	}
 
 	switch ch {
-	case '}':
+	case '}', ']':
 		return io.EOF
 	case '"':
 		b, err := p.p.ReadSubstring(ch)
@@ -78,16 +81,34 @@ func (p *arrayParser) readNext() error {
 		p.elem = rng
 		return nil
 	default:
-		lit := p.p.ReadLiteral(ch)
-		if bytes.Equal(lit, []byte("NULL")) {
-			lit = nil
+		if ch == '{' && p.isJson {
+			json, err := p.p.ReadJSON()
+			if err != nil {
+				return err
+			}
+
+			for {
+				if p.p.Peek() == ',' || p.p.Peek() == ' ' {
+					p.p.Advance()
+				} else {
+					break
+				}
+			}
+
+			p.elem = json
+			return nil
+		} else {
+			lit := p.p.ReadLiteral(ch)
+			if bytes.Equal(lit, []byte("NULL")) {
+				lit = nil
+			}
+
+			if p.p.Peek() == ',' {
+				p.p.Advance()
+			}
+
+			p.elem = lit
+			return nil
 		}
-
-		if p.p.Peek() == ',' {
-			p.p.Advance()
-		}
-
-		p.elem = lit
-		return nil
 	}
 }

dialect/pgdialect/array_parser_test.go

@@ -24,6 +24,10 @@ func TestArrayParser(t *testing.T) {
 		{`{"1","2"}`, []string{"1", "2"}},
 		{`{"{1}","{2}"}`, []string{"{1}", "{2}"}},
 		{`{[1,2),[3,4)}`, []string{"[1,2)", "[3,4)"}},
+
+		{`[]`, []string{}},
+		{`[{"'\"[]"}]`, []string{`{"'\"[]"}`}},
+		{`[{"id": 1}, {"id":2, "name":"bob"}]`, []string{"{\"id\": 1}", "{\"id\":2, \"name\":\"bob\"}"}},
 	}
 
 	for i, test := range tests {

dialect/pgdialect/array_test.go

@@ -0,0 +1,54 @@
+package pgdialect
+
+import (
+	"testing"
+
+	"github.com/uptrace/bun/schema"
+)
+
+func ptr[T any](v T) *T {
+	return &v
+}
+
+func TestArrayAppend(t *testing.T) {
+	tcases := []struct {
+		input interface{}
+		out   string
+	}{
+		{
+			input: []byte{1, 2},
+			out:   `'{1,2}'`,
+		},
+		{
+			input: []*byte{ptr(byte(1)), ptr(byte(2))},
+			out:   `'{1,2}'`,
+		},
+		{
+			input: []int{1, 2},
+			out:   `'{1,2}'`,
+		},
+		{
+			input: []*int{ptr(1), ptr(2)},
+			out:   `'{1,2}'`,
+		},
+		{
+			input: []string{"foo", "bar"},
+			out:   `'{"foo","bar"}'`,
+		},
+		{
+			input: []*string{ptr("foo"), ptr("bar")},
+			out:   `'{"foo","bar"}'`,
+		},
+	}
+
+	for _, tcase := range tcases {
+		out, err := Array(tcase.input).AppendQuery(schema.NewFormatter(New()), []byte{})
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if string(out) != tcase.out {
+			t.Errorf("expected output to be %s, was %s", tcase.out, string(out))
+		}
+	}
+}

dialect/pgdialect/parser.go

@@ -105,3 +105,39 @@ func (p *pgparser) ReadRange(ch byte) ([]byte, error) {
 
 	return p.buf, nil
 }
+
+func (p *pgparser) ReadJSON() ([]byte, error) {
+	p.Unread()
+
+	c, err := p.ReadByte()
+	if err != nil {
+		return nil, err
+	}
+
+	p.buf = p.buf[:0]
+
+	depth := 0
+	for {
+		switch c {
+		case '{':
+			depth++
+		case '}':
+			depth--
+		}
+
+		p.buf = append(p.buf, c)
+
+		if depth == 0 {
+			break
+		}
+
+		next, err := p.ReadByte()
+		if err != nil {
+			return nil, err
+		}
+
+		c = next
+	}
+
+	return p.buf, nil
+}

dialect/pgdialect/sqltype.go

@@ -86,6 +86,10 @@ func fieldSQLType(field *schema.Field) string {
 }
 
 func sqlType(typ reflect.Type) string {
+	if typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+	}
+
 	switch typ {
 	case nullStringType: // typ.Kind() == reflect.Struct, test for exact match
 		return sqltype.VarChar

internal/dbtest/pg_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/uptrace/bun"
 	"github.com/uptrace/bun/dialect/pgdialect"
 	"github.com/uptrace/bun/driver/pgdriver"
+	"github.com/uptrace/bun/schema"
 )
 
 func TestPostgresArray(t *testing.T) {
@@ -25,16 +26,20 @@ func TestPostgresArray(t *testing.T) {
 		Array1 []string  `bun:",array"`
 		Array2 *[]string `bun:",array"`
 		Array3 *[]string `bun:",array"`
+		Array4 []*string `bun:",array"`
 	}
 
 	db := pg(t)
 	t.Cleanup(func() { db.Close() })
 	mustResetModel(t, ctx, db, (*Model)(nil))
 
+	str1 := "hello"
+	str2 := "world"
 	model1 := &Model{
 		ID:     123,
 		Array1: []string{"one", "two", "three"},
 		Array2: &[]string{"hello", "world"},
+		Array4: []*string{&str1, &str2},
 	}
 	_, err := db.NewInsert().Model(model1).Exec(ctx)
 	require.NoError(t, err)
@@ -56,6 +61,12 @@ func TestPostgresArray(t *testing.T) {
 		Scan(ctx, pgdialect.Array(&strs))
 	require.NoError(t, err)
 	require.Nil(t, strs)
+
+	err = db.NewSelect().Model((*Model)(nil)).
+		Column("array4").
+		Scan(ctx, pgdialect.Array(&strs))
+	require.NoError(t, err)
+	require.Equal(t, []string{"hello", "world"}, strs)
 }
 
 func TestPostgresArrayQuote(t *testing.T) {
@@ -877,3 +888,78 @@ func TestPostgresMultiRange(t *testing.T) {
 	err = db.NewSelect().Model(out).Scan(ctx)
 	require.NoError(t, err)
 }
+
+type UserID struct {
+	ID string
+}
+
+func (u UserID) AppendQuery(fmter schema.Formatter, b []byte) ([]byte, error) {
+	v := []byte(`"` + u.ID + `"`)
+	return append(b, v...), nil
+}
+
+var _ schema.QueryAppender = (*UserID)(nil)
+
+func (r *UserID) Scan(anySrc any) (err error) {
+	src, ok := anySrc.([]byte)
+	if !ok {
+		return fmt.Errorf("pgdialect: Range can't scan %T", anySrc)
+	}
+
+	r.ID = string(src)
+	return nil
+}
+
+var _ sql.Scanner = (*UserID)(nil)
+
+func TestPostgresJSONB(t *testing.T) {
+	type Item struct {
+		Name string `json:"name"`
+	}
+	type Model struct {
+		ID        int64    `bun:",pk,autoincrement"`
+		Item      Item     `bun:",type:jsonb"`
+		ItemPtr   *Item    `bun:",type:jsonb"`
+		Items     []Item   `bun:",type:jsonb"`
+		ItemsP    []*Item  `bun:",type:jsonb"`
+		TextItemA []UserID `bun:"type:text[]"`
+	}
+
+	db := pg(t)
+	t.Cleanup(func() { db.Close() })
+	mustResetModel(t, ctx, db, (*Model)(nil))
+
+	item1 := Item{Name: "one"}
+	item2 := Item{Name: "two"}
+	uid1 := UserID{ID: "1"}
+	uid2 := UserID{ID: "2"}
+	model1 := &Model{
+		ID:        123,
+		Item:      item1,
+		ItemPtr:   &item2,
+		Items:     []Item{item1, item2},
+		ItemsP:    []*Item{&item1, &item2},
+		TextItemA: []UserID{uid1, uid2},
+	}
+	_, err := db.NewInsert().Model(model1).Exec(ctx)
+	require.NoError(t, err)
+
+	model2 := new(Model)
+	err = db.NewSelect().Model(model2).Scan(ctx)
+	require.NoError(t, err)
+	require.Equal(t, model1, model2)
+
+	var items []Item
+	err = db.NewSelect().Model((*Model)(nil)).
+		Column("items").
+		Scan(ctx, pgdialect.Array(&items))
+	require.NoError(t, err)
+	require.Equal(t, []Item{item1, item2}, items)
+
+	err = db.NewSelect().Model((*Model)(nil)).
+		Column("itemsp").
+		Scan(ctx, pgdialect.Array(&items))
+	require.NoError(t, err)
+	require.Equal(t, []Item{item1, item2}, items)
+
+}