Avoid log.Fatalf in connector code, return error instead

Also prefer `fmt.Sprint(x)` to `fmt.Sprintf("%v", x)`

flow/connectors/postgres/cdc.go

@@ -897,7 +897,7 @@ func (p *PostgresCDCSource) recToTablePKey(req *model.PullRecordsRequest,
 		if err != nil {
 			return nil, fmt.Errorf("error getting pkey column value: %w", err)
 		}
-		pkeyColsMerged = append(pkeyColsMerged, []byte(fmt.Sprintf("%v", pkeyColVal.Value))...)
+		pkeyColsMerged = append(pkeyColsMerged, []byte(fmt.Sprint(pkeyColVal.Value))...)
 	}
 
 	return &model.TableWithPkey{

flow/connectors/utils/avro/avro_writer.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"log"
 	"log/slog"
 	"os"
+	"sync"
 	"sync/atomic"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
@@ -186,14 +186,13 @@ func (p *peerDBOCFWriter) WriteOCF(w io.Writer) (int, error) {
 
 func (p *peerDBOCFWriter) WriteRecordsToS3(bucketName, key string, s3Creds utils.S3PeerCredentials) (*AvroFile, error) {
 	r, w := io.Pipe()
-	numRowsWritten := make(chan int, 1)
+	var writeOcfError error
+	var numRows int
+	var wg sync.WaitGroup
+	wg.Add(1)
 	go func() {
-		defer w.Close()
-		numRows, err := p.WriteOCF(w)
-		if err != nil {
-			log.Fatalf("%v", err)
-		}
-		numRowsWritten <- numRows
+		numRows, writeOcfError = p.WriteOCF(w)
+		wg.Done()
 	}()
 
 	s3svc, err := utils.CreateS3Client(s3Creds)
@@ -214,9 +213,12 @@ func (p *peerDBOCFWriter) WriteRecordsToS3(bucketName, key string, s3Creds utils
 	}
 
 	slog.Info("file uploaded to " + fmt.Sprintf("%s/%s", bucketName, key))
-
+	wg.Wait()
+	if writeOcfError != nil {
+		return nil, writeOcfError
+	}
 	return &AvroFile{
-		NumRecords:      <-numRowsWritten,
+		NumRecords:      numRows,
 		StorageLocation: AvroS3Storage,
 		FilePath:        key,
 	}, nil

flow/e2e/test_utils.go

@@ -505,12 +505,7 @@ func NewTStructuredLogger(logger slog.Logger) *TStructuredLogger {
 }
 
 func (l *TStructuredLogger) keyvalsToFields(keyvals []interface{}) slog.Attr {
-	var attrs []any
-	for i := 0; i < len(keyvals); i += 1 {
-		key := fmt.Sprintf("%v", keyvals[i])
-		attrs = append(attrs, key)
-	}
-	return slog.Group("test-log", attrs...)
+	return slog.Group("test-log", keyvals...)
 }
 
 func (l *TStructuredLogger) Debug(msg string, keyvals ...interface{}) {

flow/workflows/qrep_flow.go

@@ -236,13 +236,9 @@ func (q *QRepFlowExecution) processPartitions(
 		chunkSize = 1
 	}
 
-	batches := make([][]*protos.QRepPartition, 0)
+	batches := make([][]*protos.QRepPartition, 0, len(partitions)/chunkSize+1)
 	for i := 0; i < len(partitions); i += chunkSize {
-		end := i + chunkSize
-		if end > len(partitions) {
-			end = len(partitions)
-		}
-
+		end := min(i+chunkSize, len(partitions))
 		batches = append(batches, partitions[i:end])
 	}