actually do the timestamp check

Author: FGasper

internal/verifier/change_stream.go

@@ -200,7 +200,8 @@ func (verifier *Verifier) iterateChangeStream(ctx context.Context, cs *mongo.Cha
 			// Read all change events until the source reports no events.
 			// (i.e., the `getMore` call returns empty)
 			for {
-				curTs, err := extractTimestampFromResumeToken(cs.ResumeToken())
+				var curTs primitive.Timestamp
+				curTs, err = extractTimestampFromResumeToken(cs.ResumeToken())
 				if err != nil {
 					err = errors.Wrap(err, "failed to extract timestamp from change stream's resume token")
 					break
@@ -215,10 +216,9 @@ func (verifier *Verifier) iterateChangeStream(ctx context.Context, cs *mongo.Cha
 					break
 				}
 
-				var gotEvent bool
-				gotEvent, err = readAndHandleOneChangeEventBatch()
+				_, err = readAndHandleOneChangeEventBatch()
 
-				if !gotEvent || err != nil {
+				if err != nil {
 					break
 				}
 			}