Creating a proper IncompatibleSyncedRealmError class.

docs/realm.js

@@ -87,8 +87,8 @@ class Realm {
      * `config.schemaVersion` is incremented, in which case the Realm will be automatically
      * migrated to use the new schema.
      * @param {Realm~Configuration} [config] - **Required** when first creating the Realm.
-     * @throws {Error} If anything in the provided `config` is invalid or migration from RMP
-     *   version 1 to 2 is not possible.
+     * @throws {Error} If anything in the provided `config` is invalid.
+     * @throws IncompatibleSyncedRealmError} if migration from RMP version 1 to 2 is not possible.
      */
     constructor(config) {}
 
@@ -106,8 +106,8 @@ class Realm {
      * @param {Realm~Configuration} config 
      * @param  {callback(error, realm)} - will be called when the realm is ready.
      * @param  {callback(transferred, transferable)} [progressCallback] - an optional callback for download progress notifications
-     * @throws {Error} If anything in the provided `config` is invalid  or migration from RMP
-     *   version 1 to 2 is not possible.
+     * @throws {Error} If anything in the provided `config` is invalid
+     * @throws {IncompatibleSyncedRealmError} if migration from RMP version 1 to 2 is not possible
      */
     static openAsync(config, callback, progressCallback) {}
 

docs/sync.js

@@ -132,6 +132,18 @@ class AuthError extends Error {
     get type() {}
 }
 
+/**
+ * Class that describes error in migration of a Realm from Realm Mobile Platform v1.x to v2.x
+ * @memberof Realm.Sync
+ */
+class IncompatibleSyncedRealmError extends Error {
+    /**
+     * The {Realm~Configuration} of the backed up Realm.
+     * @type {Realm~Configuration}
+     */
+    get configuration() {}
+}
+
 /**
  * Class for logging in and managing Sync users.
  * @memberof Realm.Sync

lib/errors.js

@@ -20,7 +20,7 @@
 
 function AuthError(problem) {
     const error = Error.call(this, problem.title);
-    
+
     this.name = 'AuthError';
     this.message = error.message;
     this.stack = error.stack;
@@ -32,3 +32,20 @@ AuthError.__proto__ = Error;
 AuthError.prototype.__proto__ = Error.prototype;
 
 exports['AuthError'] = AuthError;
+
+
+function IncompatibleSyncedRealmError(problem, configuration) {
+    const error = Error.call(this, problem.title);
+
+    this.name = 'IncompatibleSyncedRealmError';
+    this.message = error.message;
+    this.stack = error.stack;
+    this.configuration = configuration;
+
+    Object.assign(this, problem);
+}
+
+IncompatibleSyncedRealmError.__proto__ = Error;
+IncompatibleSyncedRealmError.prototype.__proto__ = Error.prototype;
+
+exports['IncompatibleSyncedRealmError'] = IncompatibleSyncedRealmError;

lib/extensions.js

@@ -18,6 +18,8 @@
 
 'use strict';
 
+const IncompatibleSyncedRealmError = require('./Errors').IncompatibleSyncedRealmError;
+
 let getOwnPropertyDescriptors = Object.getOwnPropertyDescriptors || function(obj) {
     return Object.getOwnPropertyNames(obj).reduce(function (descriptors, name) {
         descriptors[name] = Object.getOwnPropertyDescriptor(obj, name);
@@ -59,6 +61,9 @@ module.exports = function(realmConstructor) {
                                 //FIXME: RN hangs here. Remove when node's makeCallback alternative is implemented
                                 setTimeout(() => { resolve(syncedRealm); }, 1);
                             } catch (e) {
+                                if (e.message === 'IncompatibleSyncedRealm') {
+                                    reject(new IncompatibleSyncedRealmError(e.configuration));
+                                }
                                 reject(e);
                             }
                         }
@@ -96,6 +101,9 @@ module.exports = function(realmConstructor) {
                             //FIXME: RN hangs here. Remove when node's makeCallback alternative is implemented
                             setTimeout(() => { callback(null, syncedRealm); }, 1);
                         } catch (e) {
+                            if (e.message === 'IncompatibleSyncedRealm') {
+                                throw new IncompatibleSyncedRealmError(e.configuration);
+                            }
                             setTimeout(() => { callback(e); }, 1);
                         }
                     }

src/js_realm.hpp

@@ -271,7 +271,7 @@ public:
                     }
 
                     ObjectType object = Object::create_empty(ctx);
-                    Object::set_property(ctx, object, "message", Value::from_string(ctx, "IncompatibleSyncedRealmException"));
+                    Object::set_property(ctx, object, "message", Value::from_string(ctx, "IncompatibleSyncedRealm"));
                     Object::set_property(ctx, object, "configuration", configuration);
                     throw Exception<T>(ctx, object);
                 }

tests/js/session-tests.js

@@ -469,7 +469,7 @@ module.exports = {
                     const realm = new Realm(config);
                 }
                 catch (e) {
-                    if (e.message === 'IncompatibleSyncedRealmException') {
+                    if (e instanceof IncompatibleSyncedRealmError) {
                         const backupRealm = new Realm(e.configuration);
                         TestCase.assertNotEqual(backupRealm.objects('Person').length, 0);
                         resolve();