feat: add origin private file system service

src/app/services/opfs.spec.ts

@@ -0,0 +1,66 @@
+import { TestBed } from '@angular/core/testing';
+import { vi } from 'vitest';
+import { OPFS } from './opfs';
+
+describe('OPFS', () => {
+
+  let service: OPFS;
+  let dirHandleMock: Partial<FileSystemDirectoryHandle>
+  let fileHandleMock: Partial<FileSystemFileHandle>;
+  let writeable: Partial<FileSystemWritableFileStream>
+  
+  let FILENAME_MOCK: string;
+  let DIR_MOCK: string;
+  beforeEach(() => {
+    
+    FILENAME_MOCK = 'FILENAME_MOCK';
+    DIR_MOCK = 'DIR_MOCK';
+
+    writeable = {
+      write: vi.fn().mockResolvedValue(undefined),
+      close: vi.fn().mockResolvedValue(undefined)
+    };
+    fileHandleMock = {
+      createWritable: vi.fn().mockResolvedValue(writeable),
+      getFile: vi.fn().mockResolvedValue({arrayBuffer: vi.fn()}),
+    };
+    dirHandleMock = {
+      getDirectoryHandle: vi.fn().mockResolvedValue(dirHandleMock),
+      getFileHandle: vi.fn().mockResolvedValue(fileHandleMock),
+      removeEntry: vi.fn()
+    };
+    (<any>globalThis.navigator).storage = {
+      getDirectory: vi.fn().mockResolvedValue(dirHandleMock),
+      persist: vi.fn().mockResolvedValue(true),
+      persisted: vi.fn().mockResolvedValue(true),
+      estimate: vi.fn().mockResolvedValue({ usage: 100, quota: 1000 }),
+    };
+
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(OPFS);
+
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+
+  it('should get a dir handle to write a file to storage',  async() => {
+    const getDirHandlerSpy = vi.spyOn<OPFS, any>(service, 'getDirHandle');
+    const BUFFER_MOCK = new ArrayBuffer();
+    await service.writeTo(FILENAME_MOCK, DIR_MOCK, BUFFER_MOCK)
+    expect(getDirHandlerSpy).toHaveBeenCalledOnce();
+  });
+
+  it('should get a dir handle to read a file from storage', async () => {
+    const getDirHandlerSpy = vi.spyOn<OPFS, any>(service, 'getDirHandle');
+    await service.readFrom(FILENAME_MOCK, DIR_MOCK);
+    expect(getDirHandlerSpy).toHaveBeenCalledOnce();
+  });
+  
+  it('should get a dir handle to delete a file in storage', async () => {
+    const getDirHandlerSpy = vi.spyOn<OPFS, any>(service, 'getDirHandle');
+    await service.delete(FILENAME_MOCK, DIR_MOCK);
+    expect(getDirHandlerSpy).toHaveBeenCalledOnce();
+  });
+});

src/app/services/opfs.ts

@@ -0,0 +1,32 @@
+import { Injectable } from '@angular/core';
+
+@Injectable({
+  providedIn: 'root',
+})
+export class OPFS {
+
+  async writeTo(filename: string, dir: string, data: ArrayBuffer) {
+    const dirHandler = await this.getDirHandle(dir);
+    const file = await dirHandler.getFileHandle(filename, { create: true });
+    const writable = await file.createWritable();
+    await writable.write(data);
+    await writable.close();
+  }
+
+  async readFrom(filename: string, dir: string) {
+    const dirHandler = await this.getDirHandle(dir);
+    const file = await dirHandler.getFileHandle(filename);
+    const fileData = await file.getFile();
+    return await fileData.arrayBuffer();
+  }
+  
+  async delete(filename: string, dir: string) {
+    const dirHandler = await this.getDirHandle(dir);
+    await dirHandler.removeEntry(filename);
+  }
+
+  private async getDirHandle(dir: string) {
+    const root = await navigator.storage.getDirectory();
+    return await root.getDirectoryHandle(dir, { create: true });
+  }
+}