From 9c74312402575f5e988b3355f27b43e4aab572ad Mon Sep 17 00:00:00 2001
From: mlange-42 <martin_lange_@gmx.net>
Date: Thu, 18 Apr 2024 15:10:32 +0200
Subject: [PATCH] prevent escaping special characters in JSON output

---
 CHANGELOG.md     |  1 +
 cmd/isso/main.go | 28 ++++++++++++++++------------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b12e70a..658b0b6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Other
 
 * Changed formatting functions to methods of type Solution (#13)
+* Prevent escaping special characters in JSON output (#14)
 
 ## [[v0.2.0]](https://github.com/mlange-42/isso/compare/v0.1.0...v0.2.0)
 
diff --git a/cmd/isso/main.go b/cmd/isso/main.go
index 69d9eed..b074473 100644
--- a/cmd/isso/main.go
+++ b/cmd/isso/main.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/mlange-42/isso"
 	"github.com/mlange-42/isso/fitness"
@@ -90,42 +91,45 @@ func run(file, format string, csvDelimiter string, pareto bool) (string, error)
 
 	fmt.Fprintf(os.Stderr, "Found %d solution(s)\n\n", len(solution))
 
-	output := ""
+	b := strings.Builder{}
 	switch format {
 	case "json":
-		jsData, err = json.MarshalIndent(&solution, "", "    ")
+		enc := json.NewEncoder(&b)
+		enc.SetEscapeHTML(false)
+		enc.SetIndent("", "    ")
+		err = enc.Encode(&solution)
 		if err != nil {
 			return "", err
 		}
-		output = fmt.Sprintln(string(jsData))
+		b.WriteString(fmt.Sprintln(string(jsData)))
 
 	case "table":
 		for _, sol := range solution {
-			output += fmt.Sprintln(sol.ToTable())
-			output += fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples)
-			output += fmt.Sprintln("------------------------------------------------------------")
+			b.WriteString(fmt.Sprintln(sol.ToTable()))
+			b.WriteString(fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples))
+			b.WriteString(fmt.Sprintln("------------------------------------------------------------"))
 		}
 
 	case "csv":
 		for i, sol := range solution {
-			output += fmt.Sprint(sol.ToCSV(i, csvDelimiter))
+			b.WriteString(fmt.Sprint(sol.ToCSV(i, csvDelimiter)))
 		}
 
 	case "list":
 		for _, sol := range solution {
-			output += fmt.Sprintln(sol.ToList())
-			output += fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples)
-			output += fmt.Sprintln("------------------------------------------------------------")
+			b.WriteString(fmt.Sprintln(sol.ToList()))
+			b.WriteString(fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples))
+			b.WriteString(fmt.Sprintln("------------------------------------------------------------"))
 		}
 
 	case "fitness":
 		for _, sol := range solution {
-			output += fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples)
+			b.WriteString(fmt.Sprintf("(%d trips, %d samples)\n", sol.Fitness.Trips, sol.Fitness.Samples))
 		}
 
 	default:
 		return "", fmt.Errorf("unknown format '%s'", format)
 	}
 
-	return output, nil
+	return b.String(), nil
 }