feat(caching): add caching for GET, POST, DELETE, and PUT requests

package.json

@@ -37,6 +37,7 @@
     "@types/form-data": "^2.2.1",
     "@types/node-fetch": "^2.3.2",
     "form-data": "^2.3.3",
+    "lru-cache": "^5.1.1",
     "node-fetch": "^2.3.0"
   },
   "husky": {

src/__tests__/client.test.ts

@@ -1,5 +1,6 @@
 // We use the real `Response` constructor from the actual node-fetch module
 const { Response } = require.requireActual('node-fetch');
+
 // And then mock `fetch` going forward using `Response` with mock data
 jest.mock('node-fetch', () =>
   jest.fn(() =>
@@ -14,21 +15,23 @@ const fetch = require.requireMock('node-fetch');
 import { Client } from '../client';
 import FormData from 'form-data';
 import createForm from '../helpers/createForm';
+import * as cache from '../cache';
 
 beforeEach(() => {
   fetch.mockReset();
+  jest.clearAllMocks();
 });
 
 test('Client instantiates with access token', () => {
-  const client = new Client({ access_token: 'abc123' });
-  expect(client.access_token).toBe('abc123');
+  const client = new Client({ access_token: 'abc1234' });
+  expect(client.access_token).toBe('abc1234');
   expect(client.client_id).toBeUndefined();
   expect(client.anonymous).toBe(false);
 });
 
 test('Client instantiates with client ID', () => {
-  const client = new Client({ client_id: 'abc123' });
-  expect(client.client_id).toBe('abc123');
+  const client = new Client({ client_id: 'abc12345' });
+  expect(client.client_id).toBe('abc12345');
   expect(client.access_token).toBeUndefined();
   expect(client.anonymous).toBe(true);
 });
@@ -57,11 +60,11 @@ test('requests are decorated with an access token', async () => {
 test('requests are decorated with a client ID', async () => {
   fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
   const client = new Client({ client_id: 'abc123' });
-  await client.request('https://www.blah.com', {
+  await client.request('https://www.blahs.com', {
     method: 'GET',
   });
   expect(fetch).toHaveBeenCalledTimes(1);
-  expect(fetch).toHaveBeenCalledWith('https://www.blah.com', {
+  expect(fetch).toHaveBeenCalledWith('https://www.blahs.com', {
     headers: {
       Authorization: 'Client-ID abc123',
     },
@@ -119,12 +122,74 @@ test('post() has correct headers and passed in form data reference', async () =>
   });
 });
 
+test('calls cacheGet when calling request', async () => {
+  fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
+  const client = new Client({ access_token: 'abc123' });
+  const params = {
+    image: 'R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7',
+    type: 'base64',
+  };
+
+  const cacheGetSpy = jest.spyOn(cache, 'cacheGet');
+
+  const form = createForm(params);
+
+  await client.post('https://www.abc.com', form);
+  expect(cacheGetSpy).toHaveBeenCalledTimes(1);
+});
+
+test('calls cacheSet when calling request', async () => {
+  fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
+  const client = new Client({ access_token: 'abc123' });
+  const params = {
+    image: 'R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7',
+    type: 'base64',
+  };
+
+  const cacheSetSpy = jest.spyOn(cache, 'cacheSet');
+
+  const form = createForm(params);
+
+  await client.post('https://www.abc.com', form);
+  expect(cacheSetSpy).toHaveBeenCalledTimes(1);
+});
+
+test('fetches from the cache on subsequent post requests', async () => {
+  fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
+  const client = new Client({ access_token: 'abc123' });
+  const params = {
+    image: 'R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7',
+    type: 'base64',
+  };
+
+  const cacheSetSpy = jest.spyOn(cache, 'cacheSet');
+
+  const form = createForm(params);
+
+  await client.post('https://www.abc.com', form);
+  await client.post('https://www.abc.com', form);
+  await client.post('https://www.abc.com', form);
+
+  expect(cacheSetSpy).toHaveBeenCalledTimes(1);
+});
+
+test('fetches from the cache on subsequent get requests', async () => {
+  fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
+  const client = new Client({ access_token: 'abc123' });
+  const cacheSetSpy = jest.spyOn(cache, 'cacheSet');
+  await client.get('https://www.txyz.com');
+  await client.get('https://www.txyz.com');
+  await client.get('https://www.txyz.com');
+
+  expect(cacheSetSpy).toHaveBeenCalledTimes(1);
+});
+
 test('get() has correct headers', async () => {
   fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
   const client = new Client({ access_token: 'abc123' });
-  await client.get('https://www.blah.com');
+  await client.get('https://www.xyz.com');
   expect(fetch).toHaveBeenCalledTimes(1);
-  expect(fetch).toHaveBeenCalledWith('https://www.blah.com', {
+  expect(fetch).toHaveBeenCalledWith('https://www.xyz.com', {
     headers: {
       Authorization: 'Bearer abc123',
     },
@@ -135,9 +200,9 @@ test('get() has correct headers', async () => {
 test('delete() has correct headers', async () => {
   fetch.mockReturnValue(Promise.resolve(new Response('{"success": true}')));
   const client = new Client({ access_token: 'abc123' });
-  await client.delete('https://www.blah.com');
+  await client.delete('https://www.mlop.com');
   expect(fetch).toHaveBeenCalledTimes(1);
-  expect(fetch).toHaveBeenCalledWith('https://www.blah.com', {
+  expect(fetch).toHaveBeenCalledWith('https://www.mlop.com', {
     headers: {
       Authorization: 'Bearer abc123',
     },

src/cache/index.ts

@@ -0,0 +1,24 @@
+import { ImgurApiResponse, AuthenticationRequiredResponse } from '../responses';
+
+const LRU = require('lru-cache');
+
+const options = {
+  length: function(n: number, key: any) {
+    return n * 2 + key.length;
+  },
+  maxAge: 1000 * 30 * 30,
+};
+
+export const cache = new LRU(options);
+
+export const cacheGet = (key: string) => {
+  return cache.get(key) || false;
+};
+
+export const cacheSet = (
+  key: string,
+  res: Promise<ImgurApiResponse | AuthenticationRequiredResponse>,
+) => {
+  cache.set(key, JSON.stringify(res));
+  return res;
+};

src/client.ts

@@ -1,7 +1,8 @@
 import fetch, { RequestInit } from 'node-fetch';
 import FormData from 'form-data';
 import createForm from './helpers/createForm';
-
+import { hashUrl } from './helpers/hashUrl';
+import { cacheGet, cacheSet } from './cache';
 export interface ClientOptions {
   access_token?: string;
   client_id?: string;
@@ -13,6 +14,8 @@ export type PostOrPutData =
     }
   | FormData;
 
+export type FormDataString = string;
+
 export class Client {
   public readonly access_token: string | undefined;
   public readonly client_id: string | undefined;
@@ -50,8 +53,24 @@ export class Client {
     };
 
     try {
+      const params = Object.entries(headers)
+        .map((key: any, val: any) => {
+          return `${encodeURIComponent(key)}=${encodeURIComponent(val)}`;
+        })
+        .join('&');
+      const hashKey = hashUrl(`${endpoint}${params}`);
+      const cacheData = cacheGet(hashKey);
+
+      if (cacheData) {
+        return cacheData;
+      }
+
       const response = await fetch(endpoint, { ...options, headers });
-      return response.json();
+      const json = await response.json();
+
+      cacheSet(hashKey, json);
+
+      return json;
     } catch (err) {
       return Promise.reject(new Error(err.message));
     }
@@ -93,7 +112,6 @@ export class Client {
     } else {
       form = createForm(params);
     }
-
     return this.request(endpoint, {
       method: 'POST',
       headers: form.getHeaders(),
@@ -108,9 +126,10 @@ export class Client {
    * @returns A JSON response object
    */
   get(endpoint: string): Promise<any> {
-    return this.request(endpoint, {
+    const res = this.request(endpoint, {
       method: 'GET',
     });
+    return res;
   }
 
   /**

src/helpers/hashUrl.ts

@@ -0,0 +1,16 @@
+export const hashUrl = function(str: string, seed: number = 0) {
+  let h1 = 0xdeadbeef ^ seed;
+  let h2 = 0x41c6ce57 ^ seed;
+  for (let i = 0, ch; i < str.length; i++) {
+    ch = str.charCodeAt(i);
+    h1 = Math.imul(h1 ^ ch, 2654435761);
+    h2 = Math.imul(h2 ^ ch, 1597334677);
+  }
+  h1 =
+    Math.imul(h1 ^ (h1 >>> 16), 2246822507) ^
+    Math.imul(h2 ^ (h2 >>> 13), 3266489909);
+  h2 =
+    Math.imul(h2 ^ (h2 >>> 16), 2246822507) ^
+    Math.imul(h1 ^ (h1 >>> 13), 3266489909);
+  return (4294967296 * (2097151 & h2) + (h1 >>> 0)).toString();
+};

yarn.lock

@@ -2025,7 +2025,7 @@ debug@^4.0.0, debug@^4.0.1, debug@^4.1.0, debug@^4.1.1:
   dependencies:
     ms "^2.1.1"
 
-debuglog@*, debuglog@^1.0.1:
+debuglog@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/debuglog/-/debuglog-1.0.1.tgz#aa24ffb9ac3df9a2351837cfb2d279360cd78492"
   integrity sha1-qiT/uaw9+aI1GDfPstJ5NgzXhJI=
@@ -3369,7 +3369,7 @@ import-local@^2.0.0:
     pkg-dir "^3.0.0"
     resolve-cwd "^2.0.0"
 
-imurmurhash@*, imurmurhash@^0.1.4:
+imurmurhash@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/imurmurhash/-/imurmurhash-0.1.4.tgz#9218b9b2b928a238b13dc4fb6b6d576f231453ea"
   integrity sha1-khi5srkoojixPcT7a21XbyMUU+o=
@@ -4466,7 +4466,7 @@ libnpm@^2.0.1:
     read-package-json "^2.0.13"
     stringify-package "^1.0.0"
 
-libnpmaccess@*, libnpmaccess@^3.0.1:
+libnpmaccess@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/libnpmaccess/-/libnpmaccess-3.0.1.tgz#5b3a9de621f293d425191aa2e779102f84167fa8"
   integrity sha512-RlZ7PNarCBt+XbnP7R6PoVgOq9t+kou5rvhaInoNibhPO7eMlRfS0B8yjatgn2yaHIwWNyoJDolC/6Lc5L/IQA==
@@ -4495,7 +4495,7 @@ libnpmhook@^5.0.2:
     get-stream "^4.0.0"
     npm-registry-fetch "^3.8.0"
 
-libnpmorg@*, libnpmorg@^1.0.0:
+libnpmorg@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/libnpmorg/-/libnpmorg-1.0.0.tgz#979b868c48ba28c5820e3bb9d9e73c883c16a232"
   integrity sha512-o+4eVJBoDGMgRwh2lJY0a8pRV2c/tQM/SxlqXezjcAg26Qe9jigYVs+Xk0vvlYDWCDhP0g74J8UwWeAgsB7gGw==
@@ -4520,7 +4520,7 @@ libnpmpublish@^1.1.0:
     semver "^5.5.1"
     ssri "^6.0.1"
 
-libnpmsearch@*, libnpmsearch@^2.0.0:
+libnpmsearch@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/libnpmsearch/-/libnpmsearch-2.0.1.tgz#eccc73a8fbf267d765d18082b85daa2512501f96"
   integrity sha512-K0yXyut9MHHCAH+DOiglQCpmBKPZXSUu76+BE2maSEfQN15OwNaA/Aiioe9lRFlVFOr7WcuJCY+VSl+gLi9NTA==
@@ -4529,7 +4529,7 @@ libnpmsearch@*, libnpmsearch@^2.0.0:
     get-stream "^4.0.0"
     npm-registry-fetch "^3.8.0"
 
-libnpmteam@*, libnpmteam@^1.0.1:
+libnpmteam@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/libnpmteam/-/libnpmteam-1.0.1.tgz#ff704b1b6c06ea674b3b1101ac3e305f5114f213"
   integrity sha512-gDdrflKFCX7TNwOMX1snWojCoDE5LoRWcfOC0C/fqF7mBq8Uz9zWAX4B2RllYETNO7pBupBaSyBDkTAC15cAMg==
@@ -4675,11 +4675,6 @@ lockfile@^1.0.4:
   dependencies:
     signal-exit "^3.0.2"
 
-lodash._baseindexof@*:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/lodash._baseindexof/-/lodash._baseindexof-3.1.0.tgz#fe52b53a1c6761e42618d654e4a25789ed61822c"
-  integrity sha1-/lK1OhxnYeQmGNZU5KJXie1hgiw=
-
 lodash._baseuniq@~4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash._baseuniq/-/lodash._baseuniq-4.6.0.tgz#0ebb44e456814af7905c6212fa2c9b2d51b841e8"
@@ -4688,33 +4683,11 @@ lodash._baseuniq@~4.6.0:
     lodash._createset "~4.0.0"
     lodash._root "~3.0.0"
 
-lodash._bindcallback@*:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/lodash._bindcallback/-/lodash._bindcallback-3.0.1.tgz#e531c27644cf8b57a99e17ed95b35c748789392e"
-  integrity sha1-5THCdkTPi1epnhftlbNcdIeJOS4=
-
-lodash._cacheindexof@*:
-  version "3.0.2"
-  resolved "https://registry.yarnpkg.com/lodash._cacheindexof/-/lodash._cacheindexof-3.0.2.tgz#3dc69ac82498d2ee5e3ce56091bafd2adc7bde92"
-  integrity sha1-PcaayCSY0u5ePOVgkbr9Ktx73pI=
-
-lodash._createcache@*:
-  version "3.1.2"
-  resolved "https://registry.yarnpkg.com/lodash._createcache/-/lodash._createcache-3.1.2.tgz#56d6a064017625e79ebca6b8018e17440bdcf093"
-  integrity sha1-VtagZAF2JeeevKa4AY4XRAvc8JM=
-  dependencies:
-    lodash._getnative "^3.0.0"
-
 lodash._createset@~4.0.0:
   version "4.0.3"
   resolved "https://registry.yarnpkg.com/lodash._createset/-/lodash._createset-4.0.3.tgz#0f4659fbb09d75194fa9e2b88a6644d363c9fe26"
   integrity sha1-D0ZZ+7CddRlPqeK4imZE02PJ/iY=
 
-lodash._getnative@*, lodash._getnative@^3.0.0:
-  version "3.9.1"
-  resolved "https://registry.yarnpkg.com/lodash._getnative/-/lodash._getnative-3.9.1.tgz#570bc7dede46d61cdcde687d65d3eecbaa3aaff5"
-  integrity sha1-VwvH3t5G1hzc3mh9ZdPuy6o6r/U=
-
 lodash._reinterpolate@~3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/lodash._reinterpolate/-/lodash._reinterpolate-3.0.0.tgz#0ccf2d89166af03b3663c796538b75ac6e114d9d"
@@ -4760,11 +4733,6 @@ lodash.map@^4.5.1:
   resolved "https://registry.yarnpkg.com/lodash.map/-/lodash.map-4.6.0.tgz#771ec7839e3473d9c4cde28b19394c3562f4f6d3"
   integrity sha1-dx7Hg540c9nEzeKLGTlMNWL09tM=
 
-lodash.restparam@*:
-  version "3.6.1"
-  resolved "https://registry.yarnpkg.com/lodash.restparam/-/lodash.restparam-3.6.1.tgz#936a4e309ef330a7645ed4145986c85ae5b20805"
-  integrity sha1-k2pOMJ7zMKdkXtQUWYbIWuWyCAU=
-
 lodash.set@^4.3.2:
   version "4.3.2"
   resolved "https://registry.yarnpkg.com/lodash.set/-/lodash.set-4.3.2.tgz#d8757b1da807dde24816b0d6a84bea1a76230b23"
@@ -5476,7 +5444,7 @@ npm-pick-manifest@^2.2.3:
     npm-package-arg "^6.0.0"
     semver "^5.4.1"
 
-npm-profile@*, npm-profile@^4.0.1:
+npm-profile@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/npm-profile/-/npm-profile-4.0.1.tgz#d350f7a5e6b60691c7168fbb8392c3603583f5aa"
   integrity sha512-NQ1I/1Q7YRtHZXkcuU1/IyHeLy6pd+ScKg4+DQHdfsm769TGq6HPrkbuNJVJS4zwE+0mvvmeULzQdWn2L2EsVA==
@@ -6420,7 +6388,7 @@ readable-stream@~1.1.10:
     isarray "0.0.1"
     string_decoder "~0.10.x"
 
-readdir-scoped-modules@*, readdir-scoped-modules@^1.0.0:
+readdir-scoped-modules@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/readdir-scoped-modules/-/readdir-scoped-modules-1.0.2.tgz#9fafa37d286be5d92cbaebdee030dc9b5f406747"
   integrity sha1-n6+jfShr5dksuuve4DDcm19AZ0c=