Edited detect to return null when detection fails rather than throwing error per #526

src/index.d.ts

@@ -74,11 +74,11 @@ declare namespace Tesseract {
     data: DetectData
   }
   interface DetectData {
-    tesseract_script_id: number
+    tesseract_script_id: number | null
-    script: string
+    script: string | null
-    script_confidence: number
+    script_confidence: number | null
-    orientation_degrees: number
+    orientation_degrees: number | null
-    orientation_confidence: number
+    orientation_confidence: number | null
   }
   interface Rectangle {
     left: number

src/worker-script/index.js

@@ -356,9 +356,15 @@ const detect = async ({ payload: { image } }, res) => {
     const results = new TessModule.OSResults();
 
     if (!api.DetectOS(results)) {
-      api.End();
       TessModule._free(ptr);
-      res.reject('Failed to detect OS');
+      
+      res.resolve({
+        tesseract_script_id: null,
+        script: null,
+        script_confidence: null,
+        orientation_degrees: null,
+        orientation_confidence: null,
+      });
     } else {
       const best = results.best_result;
       const oid = best.orientation_id;