Add CsvExporter and JsonExporter

export/csv_exporter.go

@@ -0,0 +1,37 @@
+package export
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/turbot/pipe-fittings/v2/constants"
+	"github.com/turbot/pipe-fittings/v2/querydisplay"
+	"github.com/turbot/pipe-fittings/v2/queryresult"
+)
+
+type CsvExporter struct {
+	ExporterBase
+}
+
+// Export processes the query result and writes CSV output to a file
+func (e *CsvExporter) Export(ctx context.Context, input ExportSourceData, filePath string) error {
+	result, ok := input.(*queryresult.Result[*queryresult.QueryTimingMetadata])
+	if !ok {
+		return fmt.Errorf("CsvExporter input must be a queryresult.Result")
+	}
+
+	// Generate csv output
+	jsonString, _, _ := querydisplay.BuildCSV(ctx, result)
+
+	// Write to file
+	return Write(filePath, strings.NewReader(jsonString))
+}
+
+func (e *CsvExporter) FileExtension() string {
+	return constants.CsvExtension
+}
+
+func (e *CsvExporter) Name() string {
+	return constants.OutputFormatCSV
+}

export/json_exporter.go

@@ -0,0 +1,37 @@
+package export
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/turbot/pipe-fittings/v2/constants"
+	"github.com/turbot/pipe-fittings/v2/querydisplay"
+	"github.com/turbot/pipe-fittings/v2/queryresult"
+)
+
+type JsonExporter struct {
+	ExporterBase
+}
+
+// Export processes the query result and writes JSON output to a file
+func (e *JsonExporter) Export(ctx context.Context, input ExportSourceData, filePath string) error {
+	result, ok := input.(*queryresult.Result[*queryresult.QueryTimingMetadata])
+	if !ok {
+		return fmt.Errorf("JsonExporter input must be a queryresult.Result")
+	}
+
+	// Generate JSON output
+	jsonString, _, _ := querydisplay.BuildJSON(ctx, result)
+
+	// Write to file
+	return Write(filePath, strings.NewReader(jsonString))
+}
+
+func (e *JsonExporter) FileExtension() string {
+	return constants.JsonExtension
+}
+
+func (e *JsonExporter) Name() string {
+	return constants.OutputFormatJSON
+}

querydisplay/display.go

@@ -211,7 +211,13 @@ func newJSONOutput() *jsonOutput {
 	}
 }
 
-func displayJSON[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (rowCount, rowErrors int) {
+func displayJSON[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (int, int) {
+	jsonOutput, rowCount, rowErrors := BuildJSON(ctx, result)
+	fmt.Println(jsonOutput) //nolint:forbidigo // intentional use of fmt
+	return rowCount, rowErrors
+}
+
+func BuildJSON[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (op string, rowCount, rowErrors int) {
 	jsonOutput := newJSONOutput()
 
 	// add column defs to the JSON output
@@ -244,29 +250,37 @@ func displayJSON[T queryresult.TimingContainer](ctx context.Context, result *que
 	if err != nil {
 		error_helpers.ShowError(ctx, err)
 		rowErrors++
-		return 0, rowErrors
+		return "", 0, rowErrors
 	}
 
 	// now we have iterated the rows, get the timing
 	if viper.IsSet(constants.ArgTiming) {
 		jsonOutput.Metadata = result.Timing.GetTiming()
 	}
 
-	// display the JSON
-	encoder := json.NewEncoder(os.Stdout)
+	// Encode the JSON output
+	var buf bytes.Buffer
+	encoder := json.NewEncoder(&buf)
 	encoder.SetIndent("", " ")
 	encoder.SetEscapeHTML(false)
 	if err := encoder.Encode(jsonOutput); err != nil {
 		//nolint:forbidigo // acceptable
-		fmt.Print("Error displaying result as JSON", err)
-		return 0, 0
+		fmt.Print("Error building JSON result", err)
+		return "", 0, 0
 	}
-	return count, rowErrors
+	return buf.String(), count, rowErrors
 }
 
-func displayCSV[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (rowCount, rowErrors int) {
+func displayCSV[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (int, int) {
+	csvOutput, rowCount, rowErrors := BuildCSV(ctx, result)
+	fmt.Print(csvOutput) //nolint:forbidigo // Print to stdout
+	return rowCount, rowErrors
+}
+
+func BuildCSV[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (op string, rowCount, rowErrors int) {
 
-	csvWriter := csv.NewWriter(os.Stdout)
+	var buf bytes.Buffer
+	csvWriter := csv.NewWriter(&buf)
 	csvWriter.Comma = []rune(viper.GetString(pconstants.ArgSeparator))[0]
 
 	if viper.GetBool(constants.ArgHeader) {
@@ -285,15 +299,15 @@ func displayCSV[T queryresult.TimingContainer](ctx context.Context, result *quer
 	if err != nil {
 		error_helpers.ShowError(ctx, err)
 		rowErrors++
-		return 0, rowErrors
+		return "", 0, rowErrors
 	}
 
 	csvWriter.Flush()
 	if csvWriter.Error() != nil {
-		error_helpers.ShowErrorWithMessage(ctx, csvWriter.Error(), "unable to print csv")
+		error_helpers.ShowErrorWithMessage(ctx, csvWriter.Error(), "unable to build csv")
 	}
 
-	return count, rowErrors
+	return buf.String(), count, rowErrors
 }
 
 func displayLine[T queryresult.TimingContainer](ctx context.Context, result *queryresult.Result[T]) (rowCount, rowErrors int) {

queryresult/result.go

@@ -1,17 +1,27 @@
 package queryresult
 
-import (
-	"time"
-)
+import "time"
 
 type RowResult struct {
 	Data  []interface{}
 	Error error
 }
+
 type TimingMetadata struct {
 	Duration time.Duration
 }
 
+type QueryTimingMetadata struct {
+	RowsReturned int    `json:"rows_returned"`
+	Duration     string `json:"duration_ms"`
+}
+
+// GetTiming implements TimingContainer - we implement this interface
+// to allow QueryTimingMetadata to be used to parameterize the ResultStreamer
+func (t QueryTimingMetadata) GetTiming() any {
+	return t
+}
+
 // TimingContainer is an interface that allows us to parameterize the Result struct
 // it must handle case of a query returning a stream of timing data OR a timing data struct directly
 // the GetTiming func is used to populate the timing data in the JSON output (as we cannot serialise a stream!)