extract into writeJSON

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bytes"
 	"context"
+	"encoding/csv"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -97,7 +98,7 @@ func newHandlerGetAPIV1Messages(cfg Config) http.HandlerFunc {
 			return
 		}
 
-		json.NewEncoder(w).Encode(map[string]any{"messages": messages})
+		writeJSON(w, map[string]any{"messages": messages})
 	}
 }
 
@@ -119,7 +120,7 @@ func newHandlerGetAPIV1Threads(cfg Config) http.HandlerFunc {
 			return
 		}
 
-		json.NewEncoder(w).Encode(map[string]any{"threads": threads})
+		writeJSON(w, map[string]any{"threads": threads})
 	}
 }
 
@@ -137,7 +138,7 @@ func newHandlerGetAPIV1ThreadsThread(cfg Config) http.HandlerFunc {
 			return
 		}
 
-		json.NewEncoder(w).Encode(map[string]any{"thread": map[string]any{"messages": messages}})
+		writeJSON(w, map[string]any{"thread": map[string]any{"messages": messages}})
 	}
 }
 
@@ -168,7 +169,7 @@ func handlerPostAPIV1EventsSlackInitialize(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	json.NewEncoder(w).Encode(map[string]any{"challenge": challenge.Challenge})
+	writeJSON(w, map[string]any{"challenge": challenge.Challenge})
 }
 
 func _newHandlerPostAPIV1EventsSlack(cfg Config) http.HandlerFunc {
@@ -243,3 +244,15 @@ func parseSince(s string) (time.Time, error) {
 
 	return time.Time{}, fmt.Errorf("failed to parse since=%q", s)
 }
+
+func writeJSON(w http.ResponseWriter, v interface{}) error {
+	return json.NewEncoder(w).Encode(v)
+}
+
+func writeCSV(w http.ResponseWriter, fields []string, values [][]string) error {
+	enc := csv.NewWriter(w)
+	if err := enc.Write(fields); err != nil {
+		return err
+	}
+	return enc.WriteAll(values)
+}