fix: Destination testing memory leak (#788)

<!--
Explain what problem this PR addresses
-->

---

Author: yevgenypats

internal/memdb/memdb.go

@@ -18,7 +18,6 @@ import (
 
 // client is mostly used for testing the destination plugin.
 type client struct {
-	schema.DefaultTransformer
 	spec          specs.Destination
 	memoryDB      map[string][]arrow.Record
 	tables        map[string]*arrow.Schema
@@ -87,8 +86,10 @@ func (c *client) overwrite(table *arrow.Schema, data arrow.Record) {
 			}
 		}
 		if found {
+			tmp := c.memoryDB[tableName][i]
 			c.memoryDB[tableName] = append(c.memoryDB[tableName][:i], c.memoryDB[tableName][i+1:]...)
 			c.memoryDB[tableName] = append(c.memoryDB[tableName], data)
+			tmp.Release()
 			return
 		}
 	}
@@ -109,6 +110,11 @@ func (c *client) Migrate(_ context.Context, tables schema.Schemas) error {
 		if changes == nil {
 			continue
 		}
+		for _, t := range c.memoryDB {
+			for _, row := range t {
+				row.Release()
+			}
+		}
 		c.memoryDB[tableName] = make([]arrow.Record, 0)
 		c.tables[tableName] = table
 	}
@@ -198,6 +204,11 @@ func (*client) Metrics() destination.Metrics {
 }
 
 func (c *client) Close(context.Context) error {
+	for _, table := range c.memoryDB {
+		for _, row := range table {
+			row.Release()
+		}
+	}
 	c.memoryDB = nil
 	return nil
 }
@@ -219,6 +230,8 @@ func (c *client) deleteStaleTable(_ context.Context, table *arrow.Schema, source
 			rowSyncTime := row.Column(syncColIndex).(*array.Timestamp).Value(0).ToTime(arrow.Microsecond).UTC()
 			if !rowSyncTime.Before(syncTime) {
 				filteredTable = append(filteredTable, c.memoryDB[tableName][i])
+			} else {
+				c.memoryDB[tableName][i].Release()
 			}
 		}
 	}

plugins/destination/plugin_testing.go

@@ -14,6 +14,7 @@ import (
 	"github.com/apache/arrow/go/v12/arrow/memory"
 	"github.com/cloudquery/plugin-sdk/v2/schema"
 	"github.com/cloudquery/plugin-sdk/v2/specs"
+	"github.com/cloudquery/plugin-sdk/v2/types"
 	"github.com/rs/zerolog"
 )
 
@@ -214,8 +215,16 @@ func PluginTestSuiteRunner(t *testing.T, newPlugin NewPluginFunc, destSpec specs
 
 func sortRecordsBySyncTime(table *schema.Table, records []arrow.Record) {
 	syncTimeIndex := table.Columns.Index(schema.CqSyncTimeColumn.Name)
+	cqIDIndex := table.Columns.Index(schema.CqIDColumn.Name)
 	sort.Slice(records, func(i, j int) bool {
 		// sort by sync time, then UUID
-		return records[i].Column(syncTimeIndex).(*array.Timestamp).Value(0).ToTime(arrow.Millisecond).Before(records[j].Column(syncTimeIndex).(*array.Timestamp).Value(0).ToTime(arrow.Millisecond))
+		first := records[i].Column(syncTimeIndex).(*array.Timestamp).Value(0).ToTime(arrow.Millisecond)
+		second := records[j].Column(syncTimeIndex).(*array.Timestamp).Value(0).ToTime(arrow.Millisecond)
+		if first.Equal(second) {
+			firstUUID := records[i].Column(cqIDIndex).(*types.UUIDArray).Value(0).String()
+			secondUUID := records[j].Column(cqIDIndex).(*types.UUIDArray).Value(0).String()
+			return strings.Compare(firstUUID, secondUUID) < 0
+		}
+		return first.Before(second)
 	})
 }

plugins/destination/plugin_testing_migrate.go

@@ -42,6 +42,7 @@ func testMigration(ctx context.Context, mem memory.Allocator, _ *testing.T, p *P
 		MaxRows:    1,
 	}
 	resource1 := testdata.GenTestData(mem, source, opts)[0]
+	resource1.Retain()
 	defer resource1.Release()
 	if err := p.writeOne(ctx, sourceSpec, syncTime, resource1); err != nil {
 		return fmt.Errorf("failed to write one: %w", err)
@@ -51,6 +52,7 @@ func testMigration(ctx context.Context, mem memory.Allocator, _ *testing.T, p *P
 		return fmt.Errorf("failed to migrate existing table: %w", err)
 	}
 	resource2 := testdata.GenTestData(mem, target, opts)[0]
+	resource2.Retain()
 	defer resource2.Release()
 	if err := p.writeOne(ctx, sourceSpec, syncTime, resource2); err != nil {
 		return fmt.Errorf("failed to write one after migration: %w", err)

plugins/destination/plugin_testing_overwrite.go

@@ -42,6 +42,9 @@ func (*PluginTestSuite) destinationPluginTestWriteOverwrite(ctx context.Context,
 		MaxRows:    2,
 	}
 	resources := testdata.GenTestData(mem, schema.CQSchemaToArrow(table), opts)
+	for _, r := range resources {
+		r.Retain()
+	}
 	defer func() {
 		for _, r := range resources {
 			r.Release()
@@ -83,6 +86,7 @@ func (*PluginTestSuite) destinationPluginTestWriteOverwrite(ctx context.Context,
 		StableUUID: *u,
 	}
 	updatedResource := testdata.GenTestData(mem, schema.CQSchemaToArrow(table), opts)[0]
+	updatedResource.Retain()
 	defer updatedResource.Release()
 	// write second time
 	if err := p.writeOne(ctx, sourceSpec, secondSyncTime, updatedResource); err != nil {

plugins/destination/plugin_testing_overwrite_delete_stale.go

@@ -48,6 +48,9 @@ func (*PluginTestSuite) destinationPluginTestWriteOverwriteDeleteStale(ctx conte
 	incResources := testdata.GenTestData(mem, incTable.ToArrowSchema(), opts)
 	allResources := resources
 	allResources = append(allResources, incResources...)
+	for _, r := range allResources {
+		r.Retain()
+	}
 	defer func() {
 		for _, r := range allResources {
 			r.Release()
@@ -96,6 +99,7 @@ func (*PluginTestSuite) destinationPluginTestWriteOverwriteDeleteStale(ctx conte
 		MaxRows:    1,
 	}
 	updatedResources := testdata.GenTestData(mem, table.ToArrowSchema(), opts)[0]
+	updatedResources.Retain()
 	defer updatedResources.Release()
 
 	if err := p.writeOne(ctx, sourceSpec, secondSyncTime, updatedResources); err != nil {

plugins/destination/plugin_testing_write_append.go

@@ -40,6 +40,7 @@ func (s *PluginTestSuite) destinationPluginTestWriteAppend(ctx context.Context,
 		MaxRows:    1,
 	}
 	record1 := testdata.GenTestData(mem, table.ToArrowSchema(), opts)[0]
+	record1.Retain()
 	defer record1.Release()
 	if err := p.writeOne(ctx, specSource, syncTime, record1); err != nil {
 		return fmt.Errorf("failed to write one second time: %w", err)
@@ -48,6 +49,7 @@ func (s *PluginTestSuite) destinationPluginTestWriteAppend(ctx context.Context,
 	secondSyncTime := syncTime.Add(10 * time.Second).UTC()
 	opts.SyncTime = secondSyncTime
 	record2 := testdata.GenTestData(mem, table.ToArrowSchema(), opts)[0]
+	record2.Retain()
 	defer record2.Release()
 
 	if !s.tests.SkipSecondAppend {