fix(orm): fix edge case exporting json (#11134)

* fix(orm): fix edge case exporting json

* add import json test

orm/model/ormtable/auto_increment.go

@@ -213,7 +213,9 @@ func (t autoIncrementTable) ExportJSON(ctx context.Context, writer io.Writer) er
 		return err
 	}
 
+	start := true
 	if seq != 0 {
+		start = false
 		bz, err := json.Marshal(seq)
 		if err != nil {
 			return err
@@ -222,14 +224,9 @@ func (t autoIncrementTable) ExportJSON(ctx context.Context, writer io.Writer) er
 		if err != nil {
 			return err
 		}
-
-		_, err = writer.Write([]byte(",\n"))
-		if err != nil {
-			return err
-		}
 	}
 
-	return t.doExportJSON(ctx, writer)
+	return t.doExportJSON(ctx, writer, start)
 }
 
 func (t *autoIncrementTable) GetTable(message proto.Message) Table {

orm/model/ormtable/auto_increment_test.go

@@ -65,6 +65,19 @@ func runAutoIncrementScenario(t *testing.T, table ormtable.AutoIncrementTable, c
 	store2 := ormtable.WrapContextDefault(testkv.NewSplitMemBackend())
 	assert.NilError(t, table.ImportJSON(store2, bytes.NewReader(buf.Bytes())))
 	assertTablesEqual(t, table, ctx, store2)
+
+	// test edge case where we have deleted all entities but we're still exporting the sequence number
+	assert.NilError(t, table.Delete(ctx, ex1))
+	assert.NilError(t, table.Delete(ctx, ex2))
+	buf = &bytes.Buffer{}
+	assert.NilError(t, table.ExportJSON(ctx, buf))
+	assert.NilError(t, table.ValidateJSON(bytes.NewReader(buf.Bytes())))
+	golden.Assert(t, buf.String(), "trivial_auto_inc_export.golden")
+	store3 := ormtable.WrapContextDefault(testkv.NewSplitMemBackend())
+	assert.NilError(t, table.ImportJSON(store3, bytes.NewReader(buf.Bytes())))
+	ex1.Id = 0
+	assert.NilError(t, table.Insert(store3, ex1))
+	assert.Equal(t, uint64(3), ex1.Id) // should equal 3 because the sequence number 2 should have been imported from JSON
 }
 
 func TestBadJSON(t *testing.T) {

orm/model/ormtable/table_impl.go

@@ -293,10 +293,10 @@ func (t tableImpl) ExportJSON(context context.Context, writer io.Writer) error {
 		return err
 	}
 
-	return t.doExportJSON(context, writer)
+	return t.doExportJSON(context, writer, true)
 }
 
-func (t tableImpl) doExportJSON(ctx context.Context, writer io.Writer) error {
+func (t tableImpl) doExportJSON(ctx context.Context, writer io.Writer, start bool) error {
 	marshalOptions := protojson.MarshalOptions{
 		UseProtoNames: true,
 		Resolver:      t.typeResolver,
@@ -304,7 +304,6 @@ func (t tableImpl) doExportJSON(ctx context.Context, writer io.Writer) error {
 
 	var err error
 	it, _ := t.List(ctx, nil)
-	start := true
 	for {
 		found := it.Next()
 

orm/model/ormtable/testdata/test_auto_inc.golden

@@ -52,3 +52,21 @@ ITERATOR 0300 -> 0301
       PK testpb.ExampleAutoIncrementTable 2 -> {"id":2,"x":"bar","y":10}
   NEXT
   VALID false
+GET 03000001 1203666f6f1805
+    PK testpb.ExampleAutoIncrementTable 1 -> {"id":1,"x":"foo","y":5}
+ORM DELETE testpb.ExampleAutoIncrementTable {"id":1,"x":"foo","y":5}
+DEL 03000001
+DEL PK testpb.ExampleAutoIncrementTable 1 -> {"id":1}
+DEL 0301666f6f
+DEL ERR:EOF
+GET 03000002 1203626172180a
+    PK testpb.ExampleAutoIncrementTable 2 -> {"id":2,"x":"bar","y":10}
+ORM DELETE testpb.ExampleAutoIncrementTable {"id":2,"x":"bar","y":10}
+DEL 03000002
+DEL PK testpb.ExampleAutoIncrementTable 2 -> {"id":2}
+DEL 0301626172
+DEL ERR:EOF
+GET 03808002 02
+    SEQ testpb.ExampleAutoIncrementTable 2
+ITERATOR 0300 -> 0301
+  VALID false

orm/model/ormtable/testdata/trivial_auto_inc_export.golden

@@ -0,0 +1 @@
+[2]