Initial project import

node_modules/promise-worker-transferable/register.js

@@ -0,0 +1,90 @@
+'use strict';
+
+var isPromise = require('is-promise');
+
+function registerPromiseWorker(callback) {
+
+  function postOutgoingMessage(e, messageId, error, result) {
+    function postMessage(msg, transferList) {
+      /* istanbul ignore if */
+      if (typeof self.postMessage !== 'function') { // service worker
+        e.ports[0].postMessage(msg, transferList);
+      } else { // web worker
+        self.postMessage(msg, transferList);
+      }
+    }
+    if (error) {
+      /* istanbul ignore else */
+      if (typeof console !== 'undefined' && 'error' in console) {
+        // This is to make errors easier to debug. I think it's important
+        // enough to just leave here without giving the user an option
+        // to silence it.
+        console.error('Worker caught an error:', error);
+      }
+      postMessage([messageId, {
+        message: error.message
+      }]);
+    } else {
+      if (result instanceof MessageWithTransferList) {
+        postMessage([messageId, null, result.message], result.transferList);
+      } else {
+        postMessage([messageId, null, result]);
+      }
+    }
+  }
+
+  function tryCatchFunc(callback, message) {
+    try {
+      return {res: callback(message, withTransferList)};
+    } catch (e) {
+      return {err: e};
+    }
+  }
+
+  function withTransferList(resMessage, transferList) {
+    return new MessageWithTransferList(resMessage, transferList);
+  } 
+
+  function handleIncomingMessage(e, callback, messageId, message) {
+
+    var result = tryCatchFunc(callback, message);
+
+    if (result.err) {
+      postOutgoingMessage(e, messageId, result.err);
+    } else if (!isPromise(result.res)) {
+        postOutgoingMessage(e, messageId, null, result.res);
+    } else {
+      result.res.then(function (finalResult) {
+        postOutgoingMessage(e, messageId, null, finalResult);
+      }, function (finalError) {
+        postOutgoingMessage(e, messageId, finalError);
+      });
+    }
+  }
+
+  function onIncomingMessage(e) {
+    var payload = e.data;
+    if (!Array.isArray(payload) || payload.length !== 2) {
+      // message doens't match communication format; ignore
+      return;
+    }
+    var messageId = payload[0];
+    var message = payload[1];
+
+    if (typeof callback !== 'function') {
+      postOutgoingMessage(e, messageId, new Error(
+        'Please pass a function into register().'));
+    } else {
+      handleIncomingMessage(e, callback, messageId, message);
+    }
+  }
+
+  function MessageWithTransferList(message, transferList) {
+    this.message = message;
+    this.transferList = transferList;
+  }
+
+  self.addEventListener('message', onIncomingMessage);
+}
+
+module.exports = registerPromiseWorker;