Allow opening Realms with asymmetric tables

RELEASENOTES.md

@@ -6,6 +6,7 @@
 
 ### Fixed
 
+- Fixed a bug where opening a Realm that contains asymmetric tables will crash the process with an error saying `You cannot query an asymmetric class`. ([#1591](https://github.com/realm/realm-studio/issues/1591))
 - Fixed an issue where opening a synchronized Realm that is open in another process would result in an error with a message `History type not consistent`. ([#1593](https://github.com/realm/realm-studio/issues/1593))
 
 ### Internals

src/services/data-exporter/json.ts

@@ -34,7 +34,7 @@ export class JSONExportEngine implements IExportEngine {
   public export(realm: Realm, destinationPath: string) {
     const resultMap: ResultMap = realm.schema.reduce(
       (map: ResultMap, objectSchema) => {
-        if (!objectSchema.embedded) {
+        if (!objectSchema.embedded && !objectSchema.asymmetric) {
           map[objectSchema.name] = realm.objects(objectSchema.name).snapshot();
         }
         return map;

src/ui/RealmBrowser/Content/AsymmetricObjectCollection.ts

@@ -0,0 +1,94 @@
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2023 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Mock implementation of Realm.Result<T> that returns empty results. This is because an asymmetric table
+ * cannot be queried and thus we cannot obtain the results wrapping it.
+ */
+export class AsymmetricObjectCollection<T extends Realm.Object>
+  extends Array<T>
+  implements Realm.Results<T>
+{
+  public readonly type: Realm.PropertyType;
+  public readonly optional = false;
+
+  constructor(schema: Realm.ObjectSchema) {
+    super();
+    this.type = schema.name;
+  }
+
+  public toJSON(): any[] {
+    return this.toJSON();
+  }
+
+  public update(): void {
+    throw new Error('Not implemented');
+  }
+
+  public description(): string {
+    throw new Error('Not implemented');
+  }
+
+  public isValid(): boolean {
+    return true;
+  }
+
+  public isEmpty(): boolean {
+    return true;
+  }
+
+  public min(property: string): any {
+    throw new Error('Not implemented');
+  }
+
+  public max(property: string): any {
+    throw new Error('Not implemented');
+  }
+
+  public sum(property: string): any {
+    throw new Error('Not implemented');
+  }
+
+  public avg(property: string): any {
+    throw new Error('Not implemented');
+  }
+
+  public filtered(): Realm.Results<T> {
+    return this;
+  }
+
+  public sorted(): Realm.Results<T> {
+    return this;
+  }
+
+  public snapshot(): Realm.Results<T> {
+    return this;
+  }
+
+  public addListener(): void {
+    throw new Error('Not implemented');
+  }
+
+  public removeListener(): void {
+    throw new Error('Not implemented');
+  }
+
+  public removeAllListeners(): void {
+    throw new Error('Not implemented');
+  }
+}

src/ui/RealmBrowser/Content/SingleObjectCollection.ts

@@ -36,7 +36,7 @@ export class SingleObjectCollection<T extends Realm.Object>
     return this.toJSON();
   }
 
-  public update() {
+  public update(): void {
     throw new Error('Not implemented');
   }
 
@@ -80,15 +80,15 @@ export class SingleObjectCollection<T extends Realm.Object>
     return this;
   }
 
-  public addListener() {
+  public addListener(): void {
     throw new Error('Not implemented');
   }
 
-  public removeListener() {
+  public removeListener(): void {
     throw new Error('Not implemented');
   }
 
-  public removeAllListeners() {
+  public removeAllListeners(): void {
     throw new Error('Not implemented');
   }
 }

src/ui/RealmBrowser/index.tsx

@@ -50,6 +50,7 @@ import { isPrimitive } from './primitives';
 import { RealmBrowser } from './RealmBrowser';
 import * as schemaUtils from './schema-utils';
 import { SingleObjectCollection } from './Content/SingleObjectCollection';
+import { AsymmetricObjectCollection } from './Content/AsymmetricObjectCollection';
 
 // TODO: Remove this interface once the Realm.ObjectSchemaProperty
 // has a name parameter in its type definition.
@@ -637,10 +638,14 @@ class RealmBrowserContainer
 
   private getClassFocus = (className: string): IClassFocus => {
     if (this.realm) {
+      const schema = this.realm.schema.find(s => s.name === className);
+
       return {
         kind: 'class',
         className,
-        results: this.realm.objects(className),
+        results: schema?.asymmetric
+          ? new AsymmetricObjectCollection(schema)
+          : this.realm.objects(className),
         properties: this.derivePropertiesFromClassName(className),
         isEmbedded: this.isEmbeddedType(className),
       };
@@ -700,7 +705,8 @@ class RealmBrowserContainer
 
   private getSchemaLength = (name: string) => {
     if (this.realm) {
-      return this.realm.objects(name).length;
+      const schema = this.realm.schema.find(s => s.name === name);
+      return schema?.asymmetric ? 0 : this.realm.objects(name).length;
     } else {
       return 0;
     }