Merge pull request #90 from richard-lopes-ifood/file-storage

File storage: persisting changes over restarts

package.json

@@ -69,6 +69,7 @@
     "cz-conventional-changelog": "^3.3.0",
     "husky": "^4.2.5",
     "jest": "^26.6.3",
+    "memfs": "^3.2.2",
     "mock-fs": "^4.12.0",
     "prettier": "2.0.4",
     "pretty-quick": "^2.0.1",

source/interfaces/ServerOptions.ts

@@ -3,6 +3,7 @@ import ProxyProperties from './ProxyProperties';
 import Throttling from './Throttling';
 import MethodOverride from './MethodOverride';
 import { RequestHandler } from 'express';
+import { FileStorageOptions } from '../storage';
 
 export default interface ServerOptions {
   basePath?: string;
@@ -13,4 +14,5 @@ export default interface ServerOptions {
   pagination?: PaginationProperties;
   proxies: Array<ProxyProperties>;
   throttlings: Array<Throttling>;
+  fileStorageOptions?: FileStorageOptions;
 }

source/overrides.spec.ts

@@ -1,5 +1,6 @@
 import { getMockReq, getMockRes } from '@jest-mock/express';
 import { mocked } from 'ts-jest/utils';
+import { fs as inMemoryFileSystem } from 'memfs';
 
 import { Response, RouteProperties } from './interfaces';
 
@@ -12,6 +13,7 @@ import {
 import { OverrideManager } from './overrides';
 import { RouteManager } from './routes';
 import { Middleware } from './types';
+import { FileStorage } from './storage';
 
 jest.mock('../source/prompts');
 
@@ -222,16 +224,7 @@ describe('source/override.ts', () => {
       describe('when selecting a method override', () => {
         beforeEach(() => {
           routeManager.setAll(routes);
-
-          mocked(promptRoutePath).mockImplementation(async () => ({
-            url: '/dogs',
-          }));
-          mocked(promptRouteMethodType).mockImplementation(async () => ({
-            type: 'GET',
-          }));
-          mocked(promptRouteMethodOverride).mockImplementation(async () => ({
-            name: 'Doggernaut',
-          }));
+          mockOverridePrompts('GET', '/dogs', 'Doggernaut');
         });
 
         it('prompts and changes a route method override', async () => {
@@ -357,5 +350,71 @@ describe('source/override.ts', () => {
         });
       });
     });
+
+    describe('OverrideManager with FileStorage', () => {
+      const override = {
+        routePath: '/dogs',
+        methodType: 'get',
+        name: 'Doggernaut',
+      };
+
+      function createOverrideManager(fileStorage: FileStorage<'overrides'>) {
+        const overrideManager = new OverrideManager(routeManager, fileStorage);
+        overrideManager.applyExternalOverrides();
+      }
+
+      it('loads overrides from file storage', () => {
+        const fileStorage = createFileStorage();
+        fileStorage.setItem('overrides', [override]);
+        createOverrideManager(fileStorage);
+        expect(overrideManager.getAllSelected()).toContainEqual(override);
+      });
+
+      it('persists an override to file storage', async () => {
+        const fileStorage = createFileStorage();
+        mockOverridePrompts('GET', '/dogs', 'Doggernaut');
+        createOverrideManager(fileStorage);
+        await overrideManager.choose();
+        expect(fileStorage.getItem('overrides')).toContainEqual(override);
+      });
+
+      it('properly clears and apply external (file) overrides', async () => {
+        const fileStorage = createFileStorage();
+        fileStorage.setItem('overrides', [override]);
+        const overrideManager = new OverrideManager(routeManager, fileStorage);
+        overrideManager.applyExternalOverrides();
+        expect(fileStorage.getItem('overrides')).toContainEqual(override);
+
+        fileStorage.clear();
+        expect(fileStorage.isEmpty()).toBeTruthy();
+
+        overrideManager.applyExternalOverrides();
+        expect(fileStorage.getItem('overrides')).toContainEqual(override);
+      });
+    });
   });
 });
+
+function mockOverridePrompts(
+  methodType: string,
+  routePath: string,
+  name: string
+) {
+  mocked(promptRoutePath).mockImplementation(async () => ({
+    url: routePath,
+  }));
+  mocked(promptRouteMethodType).mockImplementation(async () => ({
+    type: methodType,
+  }));
+  mocked(promptRouteMethodOverride).mockImplementation(async () => ({
+    name: name,
+  }));
+}
+
+function createFileStorage() {
+  return new FileStorage<'overrides'>({
+    enabled: true,
+    path: '/.storage',
+    fs: inMemoryFileSystem as any,
+  });
+}

source/overrides.ts

@@ -22,6 +22,7 @@ import {
   formatMethodType,
   RouteManager,
 } from './routes';
+import { FileStorage } from './storage';
 import { Middleware } from './types';
 
 const OVERRIDE_DEFAULT_OPTION = 'Default';
@@ -62,16 +63,42 @@ function findSelectedMethodOverride(method: Method) {
   return method.overrides?.find(propSatisfies(equals(true), 'selected'));
 }
 
-export class OverrideManager {
-  private routeManager: RouteManager;
+const FILE_STORAGE_KEY = 'overrides';
 
+export class OverrideManager {
   /**
    * Creates a new override manager.
    *
    * @param routeManager An instance of route manager
    */
-  constructor(routeManager: RouteManager) {
-    this.routeManager = routeManager;
+  constructor(
+    private routeManager: RouteManager,
+    private fileStorage?: FileStorage<typeof FILE_STORAGE_KEY>
+  ) {}
+
+  applyExternalOverrides() {
+    if (!this.fileStorage?.options.enabled || !this.fileStorage.isInitialized())
+      return;
+
+    if (this.fileStorage.isEmpty()) {
+      this.fileStorage?.setItem(FILE_STORAGE_KEY, this.getAllSelected());
+    } else {
+      const persistedOverrides = this.fileStorage.getItem<Override[]>(
+        FILE_STORAGE_KEY
+      );
+
+      persistedOverrides?.forEach((override) => {
+        const overridableRoutes = this.getAll();
+        const url = override.routePath;
+        const route = findRouteByUrl(overridableRoutes, url);
+        const type = override.methodType;
+        const overrides = getMethodOverridesByType(route, type.toLowerCase());
+        const name = override.name;
+        overrides.forEach((override) => {
+          override.selected = override.name === name;
+        });
+      });
+    }
   }
 
   /**
@@ -128,6 +155,8 @@ export class OverrideManager {
       override.selected = override.name === name;
     });
 
+    this.fileStorage?.setItem('overrides', this.getAllSelected());
+
     return { routePath: url, methodType: type, name };
   }
 

source/server.ts

@@ -19,6 +19,7 @@ import { ThrottlingManager } from './throttling';
 import { UIManager } from './ui';
 import { GraphQLManager } from './graphql';
 import { join } from 'path';
+import { FileStorage } from './storage';
 
 export function createServer(options = {} as ServerOptions): Server {
   const {
@@ -29,16 +30,19 @@ export function createServer(options = {} as ServerOptions): Server {
     overrides,
     proxies,
     throttlings,
+    fileStorageOptions,
   } = options;
 
+  const fileStorage = new FileStorage(fileStorageOptions);
   const routeManager = new RouteManager(overrides);
-  const overrideManager = new OverrideManager(routeManager);
+  const overrideManager = new OverrideManager(routeManager, fileStorage);
   const proxyManager = new ProxyManager(routeManager, proxies, basePath);
   const throttlingManager = new ThrottlingManager(throttlings);
   const uiManager = new UIManager(
     proxyManager,
     throttlingManager,
-    overrideManager
+    overrideManager,
+    fileStorage
   );
 
   const expressServer: express.Application = express();
@@ -121,6 +125,7 @@ export function createServer(options = {} as ServerOptions): Server {
       routeManager.setAll(routes);
       routeManager.addDocsRoute(basePath, docsRoute);
       routeManager.getAll().forEach(createRoute);
+      overrideManager.applyExternalOverrides();
     },
 
     /**
@@ -162,11 +167,20 @@ export function createServer(options = {} as ServerOptions): Server {
         );
       }
 
+      async function onResetFileStorage() {
+        fileStorage.clear();
+        uiManager.drawDashboard();
+      }
+
       inputManager.addListener('c', onConnection);
       inputManager.addListener('t', onThrottling);
       inputManager.addListener('o', onOverride);
       inputManager.addListener('p', onRouteProxy);
 
+      if (fileStorage.options.enabled) {
+        inputManager.addListener('x', onResetFileStorage);
+      }
+
       expressServer.listen(port);
     },
   };

source/storage.spec.ts

@@ -0,0 +1,63 @@
+import { FileStorage } from './storage';
+import { fs as inMemoryFileSystem, vol } from 'memfs';
+
+describe('FileStorage', () => {
+  beforeEach(() => {
+    vol.reset();
+  });
+
+  it('throws an error when file is invalid', () => {
+    inMemoryFileSystem.writeFileSync('/.storage', 'abc');
+    createFileStorage();
+    expect(() => {
+      createFileStorage().getItem('foo');
+    }).toThrow('Invalid file storage content');
+  });
+
+  it('throws an error when path is missing', () => {
+    expect(() => {
+      new FileStorage({ enabled: true });
+    }).toThrow('FileStorage path option is missing');
+  });
+
+  it('does not initializes store if disabled', () => {
+    expect(() => {
+      new FileStorage({ enabled: false, path: '/.storage' });
+      inMemoryFileSystem.readFileSync('/.storage', 'utf-8');
+    }).toThrowError("ENOENT: no such file or directory, open '/.storage'");
+  });
+
+  it('properly creates an empty storage when the storage file does not exist', () => {
+    createFileStorage();
+    expect(inMemoryFileSystem.readFileSync('/.storage', 'utf-8')).toEqual('{}');
+  });
+
+  it('properly creates a storage with the content of a existing file', () => {
+    inMemoryFileSystem.writeFileSync(
+      '/.storage',
+      '{ "foo": { "key": "value" } }'
+    );
+    createFileStorage();
+    expect(createFileStorage().getItem('foo')).toEqual({ key: 'value' });
+  });
+
+  it('sets and gets item from storage', () => {
+    expect(() => {
+      createFileStorage().setItem('foo', { key: 'value' });
+    }).not.toThrow();
+
+    expect(createFileStorage().getItem('foo')).toEqual({ key: 'value' });
+  });
+
+  it('gets an unexisting item from storage', () => {
+    expect(createFileStorage().getItem('foo')).toEqual(undefined);
+  });
+});
+
+function createFileStorage() {
+  return new FileStorage<'foo'>({
+    enabled: true,
+    path: '/.storage',
+    fs: inMemoryFileSystem as any,
+  });
+}