refactor: rename Extractor Exec method

internal/app/etl/extractors/main.go

@@ -3,12 +3,14 @@ package extractors
 import (
 	"context"
 	"errors"
+	"fmt"
 	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
 
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/config"
+	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/convert"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/custom_errors"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/etl"
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
@@ -57,7 +59,7 @@ func Consume(
 				return
 			}
 
-			rowsReadResult, err := extractor.Exec(
+			rowsReadResult, err := extractor.ProcessPartition(
 				ctx,
 				tableInfo,
 				columns,
@@ -99,3 +101,30 @@ func Consume(
 		}
 	}
 }
+
+func errorFromLastRow(
+	lastRow models.UnknownRowValues,
+	indexPrimaryKey int,
+	partition models.Partition,
+	previousError error,
+) error {
+	lastIdRawValue := lastRow[indexPrimaryKey]
+
+	lastId, ok := convert.ToInt64(lastIdRawValue)
+	if !ok {
+		currentPartition := partition
+		currentPartition.RetryCounter = 3
+		return &custom_errors.ExtractorError{
+			Partition: currentPartition,
+			HasLastId: true,
+			Msg:       fmt.Sprintf("Couldn't cast last id value as int: %s", previousError.Error()),
+		}
+	}
+
+	return &custom_errors.ExtractorError{
+		Partition: partition,
+		HasLastId: true,
+		LastId:    lastId,
+		Msg:       previousError.Error(),
+	}
+}