refactor: use Promise.all to await for independent promises (#373)

lib/EntityManager.ts

@@ -132,8 +132,10 @@ export class EntityManager<D extends IDatabaseDriver = IDatabaseDriver> {
    * where first element is the array of entities and the second is the count.
    */
   async findAndCount<T extends AnyEntity<T>>(entityName: EntityName<T>, where: FilterQuery<T>, populate?: string[] | boolean | FindOptions, orderBy?: QueryOrderMap, limit?: number, offset?: number): Promise<[T[], number]> {
-    const entities = await this.find(entityName, where, populate as string[], orderBy, limit, offset);
-    const count = await this.count<T>(entityName, where);
+    const [entities, count] = await Promise.all([
+      this.find(entityName, where, populate as string[], orderBy, limit, offset),
+      this.count(entityName, where),
+    ]);
 
     return [entities, count];
   }

lib/cache/FileCacheAdapter.ts

@@ -34,9 +34,12 @@ export class FileCacheAdapter implements CacheAdapter {
    * @inheritdoc
    */
   async set(name: string, data: any, origin: string): Promise<void> {
-    const path = await this.path(name);
+    const [path, hash] = await Promise.all([
+      this.path(name),
+      this.getHash(origin),
+    ]);
+
     const opts = this.pretty ? { spaces: 2 } : {};
-    const hash = await this.getHash(origin);
     await writeJSON(path, { data, origin, hash }, opts);
   }
 
@@ -47,9 +50,9 @@ export class FileCacheAdapter implements CacheAdapter {
     const path = await this.path('*');
     const files = await globby(path);
 
-    for (const file of files) {
-      await unlink(file);
-    }
+    await Promise.all(
+      files.map((file) => unlink(file)),
+    );
   }
 
   private async path(name: string): Promise<string> {

lib/schema/SchemaGenerator.ts

@@ -17,10 +17,12 @@ export class SchemaGenerator {
               private readonly config: Configuration) { }
 
   async generate(): Promise<string> {
-    let ret = await this.getDropSchemaSQL(false);
-    ret += await this.getCreateSchemaSQL(false);
+    const [dropSchema, createSchema] = await Promise.all([
+      this.getDropSchemaSQL(false),
+      this.getCreateSchemaSQL(false),
+    ]);
 
-    return this.wrapSchema(ret);
+    return this.wrapSchema(dropSchema + createSchema);
   }
 
   async createSchema(wrap = true): Promise<void> {

tests/issues/GH228.test.ts

@@ -68,8 +68,11 @@ describe('GH issue 228', () => {
       orderBy: { type: 'asc' },
       populate: true,
     });
-    expect(mock.mock.calls[0][0]).toMatch('select `e0`.* from `a` as `e0` order by `e0`.`type_id` asc');
-    expect(mock.mock.calls[1][0]).toMatch('select `e0`.* from `b` as `e0` where `e0`.`id` in (?)');
+
+    const queries: string[] = mock.mock.calls.map(c => c[0]).sort();
+    expect(queries).toHaveLength(3);
+    expect(queries[0]).toMatch('select `e0`.* from `a` as `e0` order by `e0`.`type_id` asc');
+    expect(queries[1]).toMatch('select `e0`.* from `b` as `e0` where `e0`.`id` in (?)');
   });
 
 });