Use format detector feature for TextViewer

QuickLook.Plugin/QuickLook.Plugin.TextViewer/Detectors/JSONDetector.cs

@@ -0,0 +1,52 @@
+// Copyright © 2017-2025 QL-Win Contributors
+//
+// This file is part of QuickLook program.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using System.Text.RegularExpressions;
+
+namespace QuickLook.Plugin.TextViewer.Detectors;
+
+public class JSONDetector : IFormatDetector
+{
+    public string Name => "JSON";
+
+    public string Extension => ".json";
+
+    public bool Detect(string text)
+    {
+        if (string.IsNullOrWhiteSpace(text)) return false;
+
+        // TODO: Use AsSpan to improve
+
+        var trimmedStart = text.TrimStart();
+
+        if (trimmedStart.StartsWith("{") || trimmedStart.StartsWith("["))
+        {
+            var trimmedEnd = text.TrimEnd();
+
+            if (trimmedEnd.EndsWith("}") || trimmedEnd.EndsWith("]"))
+            {
+                // At least one key exists
+                if (Regex.IsMatch(text, @"""[^""]+""\s*:"))
+                {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+}