improve error handling

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "diabloweb",
-  "version": "1.0.34",
+  "version": "1.0.35",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "diabloweb",
-  "version": "1.0.34",
+  "version": "1.0.35",
   "private": true,
   "dependencies": {
     "@babel/core": "7.4.3",

src/App.js

@@ -155,13 +155,19 @@ class App extends React.Component {
   }
 
   onError(message, stack) {
-    if (stack) {
-      mapStackTrace(stack, stack => {
-        this.setState(({error}) => !error && {error: {message, stack: stack.join("\n")}});
-      });
-    } else {
-      this.setState(({error}) => !error && {error: {message}});
-    }
+    (async () => {
+      const errorObject = {message};
+      if (this.saveName) {
+        errorObject.save = await (await this.fs).fileUrl(this.saveName);
+      }
+      if (stack) {
+        mapStackTrace(stack, stack => {
+          this.setState(({error}) => !error && {error: {...errorObject, stack: stack.join("\n")}});
+        });
+      } else {
+        this.setState(({error}) => !error && {error: errorObject});
+      }
+    })();
   }
 
   openKeyboard(rect) {
@@ -641,7 +647,7 @@ class App extends React.Component {
               <p className="header">The following error has occurred:</p>
               <p className="body">{error.message}</p>
               <p className="footer">Click to create an issue on GitHub</p>
-              {this.saveName != null && <p className="link" onClick={this.downloadSave}>Download save file</p>}
+              {error.save != null && <a href={error.save} download={this.saveName}>Download save file</a>}
             </Link>
           )}
           {!!loading && !started && !error && (

src/api/game.worker.js

@@ -20,6 +20,14 @@ let drawBelt = null;
 let is_spawn = false;
 let websocket = null;
 
+function onError(err, action="error") {
+  if (err instanceof Error) {
+    worker.postMessage({action, error: err.toString(), stack: err.stack});
+  } else {
+    worker.postMessage({action, error: err.toString()});
+  }
+}
+
 const ChunkSize = 1 << 20;
 class RemoteFile {
   constructor(url) {
@@ -27,7 +35,7 @@ class RemoteFile {
     request.open('HEAD', url, false);
     request.send();
     if (request.status < 200 || request.status >= 300) {
-      worker.postMessage({action: "error", error: `Failed to load remote file`});
+      throw Error('Failed to load remote file');
     }
     this.byteLength = parseInt(request.getResponseHeader('Content-Length'));
 
@@ -54,7 +62,7 @@ class RemoteFile {
       request.responseType = 'arraybuffer';
       request.send();
       if (request.status < 200 || request.status >= 300) {
-        worker.postMessage({action: "error", error: `Failed to load remote file`});
+        throw Error('Failed to load remote file');
       } else {
         const header = request.getResponseHeader('Content-Range');
         let m, start = 0;
@@ -75,7 +83,7 @@ class RemoteFile {
 
 const DApi = {
   exit_error(error) {
-    worker.postMessage({action: "error", error});
+    throw Error(error);
   },
 
   exit_game() {
@@ -131,10 +139,10 @@ const DApi = {
           }
         }, code => {
           if (typeof code !== "number") {
-            worker.postMessage({action: "error", error: code.toString(), stack: code.stack});
-            code = 3;
+            throw code;
+          } else {
+            call_api("SNet_WebsocketStatus", code);
           }
-          call_api("SNet_WebsocketStatus", code);
         });
       } else {
         call_api("SNet_WebsocketStatus", 0);
@@ -150,7 +158,7 @@ const DApi = {
     return websocket ? websocket.readyState !== 1 : false;
   },
 };
-
+/*
 let frameTime = 0, lastTime = 0;
 function getFPS() {
   const time = performance.now();
@@ -161,7 +169,7 @@ function getFPS() {
   lastTime = time;
   return frameTime ? 1000.0 / frameTime : 0.0;
 }
-
+*/
 const DApi_renderLegacy = {
   draw_begin() {
     renderBatch = {
@@ -281,7 +289,7 @@ function try_api(func) {
   try {
     func();
   } catch (e) {
-    worker.postMessage({action: "error", error: e.toString(), stack: e.stack});
+    onError(e);
   }
 }
 
@@ -409,7 +417,7 @@ worker.addEventListener("message", ({data}) => {
     files = data.files;
     init_game(data.mpq, data.spawn, data.offscreen).then(
       () => worker.postMessage({action: "loaded"}),
-      e => worker.postMessage({action: "failed", error: e.toString(), stack: e.stack}));
+      e => onError(e, "failed"));
     break;
   case "event":
     call_api(data.func, ...data.params);

src/api/loader.js

@@ -102,7 +102,7 @@ async function do_load_game(api, audio, mpq, spawn) {
           api.onError(data.error, data.stack);
           break;
         case "failed":
-          reject(Error(data.stack || data.error));
+          reject({message: data.error, stack: data.stack});
           break;
         case "progress":
           api.onProgress({text: data.text, loaded: data.loaded, total: data.total});

src/fs.js

@@ -93,6 +93,13 @@ export default async function create_fs(load) {
       clear: () => store.clear(),
       download: name => downloadFile(store, name),
       upload: file => uploadFile(store, files, file),
+      fileUrl: async name => {
+        const file = await store.get(name.toLowerCase());
+        if (file) {
+          const blob = new Blob([file], {type: 'binary/octet-stream'});
+          return URL.createObjectURL(blob);
+        }
+      },
     };
   } catch (e) {
     window.DownloadFile = () => console.error('IndexedDB is not supported');
@@ -104,6 +111,7 @@ export default async function create_fs(load) {
       clear: () => Promise.resolve(),
       download: () => Promise.resolve(),
       upload: () => Promise.resolve(),
+      fileUrl: () => Promise.resolve(),
     };
   }  
 }