From ad9aafa084a5bafada7fc06f02d75d5eb48ce0f2 Mon Sep 17 00:00:00 2001
From: petruki <31597636+petruki@users.noreply.github.com>
Date: Tue, 23 May 2023 18:12:47 -0700
Subject: [PATCH] Closes #11 - Added Snapshot Auto Update scheduler

---
 README.md                            |  7 ++-
 snapshot/dev_v2.json                 | 26 +++++++++++
 src/lib/utils/snapshotAutoUpdater.ts | 15 ++++++
 src/switcher-client.ts               | 70 ++++++++++++++++++----------
 src/types/index.d.ts                 |  1 +
 test/playground/index.ts             | 21 ++++++++-
 test/switcher-snapshot.test.ts       | 42 +++++++++++++++--
 test/switcher-watch-snapshot.test.ts |  3 +-
 8 files changed, 151 insertions(+), 34 deletions(-)
 create mode 100644 snapshot/dev_v2.json
 create mode 100644 src/lib/utils/snapshotAutoUpdater.ts

diff --git a/README.md b/README.md
index d6ff0dc..2b43795 100644
--- a/README.md
+++ b/README.md
@@ -63,11 +63,12 @@ You can also activate features such as offline and silent mode:
 const offline = true;
 const logger = true;
 const snapshotLocation = './snapshot/';
+const snapshotAutoUpdateInterval = 3000;
 const silentMode = true;
 const retryAfter = '5m';
 
 Switcher.buildContext({ url, apiKey, domain, component, environment }, {
-    offline, logger, snapshotLocation, silentMode, retryAfter
+    offline, logger, snapshotLocation, snapshotAutoUpdateInterval, silentMode, retryAfter
 });
 
 const switcher = Switcher.factory();
@@ -76,6 +77,7 @@ const switcher = Switcher.factory();
 - **offline**: If activated, the client will only fetch the configuration inside your snapshot file. The default value is 'false'.
 - **logger**: If activated, it is possible to retrieve the last results from a given Switcher key using Switcher.getLogger('KEY')
 - **snapshotLocation**: Location of snapshot files. The default value is './snapshot/'.
+- **snapshotAutoUpdateInterval**: Enable Snapshot Auto Update given an interval in ms (default: 0 disabled).
 - **silentMode**: If activated, all connectivity issues will be ignored and the client will automatically fetch the configuration into your snapshot file.
 - **retryAfter** : Time given to the module to re-establish connectivity with the API - e.g. 5s (s: seconds - m: minutes - h: hours).
 - **regexMaxBlackList**: Number of entries cached when REGEX Strategy fails to perform (reDOS safe) - default: 50
@@ -165,7 +167,8 @@ Switcher.checkSwitchers(['FEATURE01', 'FEATURE02'])
 
 ## Loading Snapshot from the API
 This step is optional if you want to load a copy of the configuration that can be used to eliminate latency when offline mode is activated.<br>
-Activate watchSnapshot optionally passing true in the arguments.
+Activate watchSnapshot optionally passing true in the arguments.<br>
+Auto load Snapshot from API passing true as second argument.
 
 ```ts
 Switcher.loadSnapshot();
diff --git a/snapshot/dev_v2.json b/snapshot/dev_v2.json
new file mode 100644
index 0000000..17dd1d2
--- /dev/null
+++ b/snapshot/dev_v2.json
@@ -0,0 +1,26 @@
+{
+    "data": {
+        "domain": {
+            "name": "Business",
+            "description": "Business description",
+            "version": 1588557288040,
+            "activated": true,
+            "group": [
+                {
+                    "name": "Rollout 2030",
+                    "description": "Changes that will be applied during the rollout",
+                    "activated": true,
+                    "config": [
+                        {
+                            "key": "FF2FOR2030",
+                            "description": "Feature Flag",
+                            "activated": true,
+                            "strategies": [],
+                            "components": []
+                        }
+                    ]
+                }
+            ]
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/lib/utils/snapshotAutoUpdater.ts b/src/lib/utils/snapshotAutoUpdater.ts
new file mode 100644
index 0000000..f00d725
--- /dev/null
+++ b/src/lib/utils/snapshotAutoUpdater.ts
@@ -0,0 +1,15 @@
+export default class SnapshotAutoUpdater {
+  static _worker: number | undefined;
+
+  static schedule(interval: number, checkSnapshot: () => void) {
+    if (this._worker) {
+      this.terminate();
+    }
+
+    this._worker = setInterval(() => checkSnapshot(), interval);
+  }
+
+  static terminate() {
+    clearInterval(this._worker);
+  }
+}
diff --git a/src/switcher-client.ts b/src/switcher-client.ts
index f27d9ae..5fd19f8 100644
--- a/src/switcher-client.ts
+++ b/src/switcher-client.ts
@@ -3,6 +3,7 @@ import Bypasser from './lib/bypasser/index.ts';
 import ExecutionLogger from './lib/utils/executionLogger.ts';
 import DateMoment from './lib/utils/datemoment.ts';
 import TimedMatch from './lib/utils/timed-match/index.ts';
+import SnapshotAutoUpdater from './lib/utils/snapshotAutoUpdater.ts';
 import { checkSwitchers, loadDomain, validateSnapshot } from './lib/snapshot.ts';
 import * as services from './lib/remote.ts';
 import checkCriteriaOffline from './lib/resolver.ts';
@@ -56,27 +57,22 @@ export class Switcher {
     this._context.environment = context.environment || DEFAULT_ENVIRONMENT;
 
     // Default values
-    this._options = {};
-    this._options.offline = DEFAULT_OFFLINE;
-    this._options.snapshotLocation = DEFAULT_SNAPSHOT_LOCATION;
-    this._options.logger = DEFAULT_LOGGER;
+    this._options = {
+      snapshotAutoUpdateInterval: 0,
+      snapshotLocation: options?.snapshotLocation || DEFAULT_SNAPSHOT_LOCATION,
+      offline: options?.offline != undefined ? options.offline : DEFAULT_OFFLINE,
+      logger: options?.logger != undefined ? options.logger : DEFAULT_LOGGER,
+    };
 
     if (options) {
-      if ('offline' in options) {
-        this._options.offline = options.offline;
-      }
-
-      if ('snapshotLocation' in options) {
-        this._options.snapshotLocation = options.snapshotLocation;
-      }
-
       if ('silentMode' in options) {
         this._options.silentMode = options.silentMode;
         this.loadSnapshot();
       }
 
-      if ('logger' in options) {
-        this._options.logger = options.logger;
+      if ('snapshotAutoUpdateInterval' in options) {
+        this._options.snapshotAutoUpdateInterval = options.snapshotAutoUpdateInterval;
+        this.scheduleSnapshotAutoUpdate();
       }
 
       if ('retryAfter' in options) {
@@ -113,17 +109,17 @@ export class Switcher {
         Date.now() > (Switcher._context.exp * 1000)
       ) {
         await Switcher._auth();
+      }
 
-        const result = await validateSnapshot(
-          Switcher._context,
-          Switcher._options.snapshotLocation,
-          Switcher._snapshot.data.domain.version,
-        );
+      const result = await validateSnapshot(
+        Switcher._context,
+        Switcher._options.snapshotLocation,
+        Switcher._snapshot.data.domain.version,
+      );
 
-        if (result) {
-          Switcher.loadSnapshot();
-          return true;
-        }
+      if (result) {
+        Switcher.loadSnapshot();
+        return true;
       }
     }
 
@@ -135,14 +131,14 @@ export class Switcher {
    *
    * @param watchSnapshot enable watchSnapshot when true
    */
-  static async loadSnapshot(watchSnapshot?: boolean) {
+  static async loadSnapshot(watchSnapshot?: boolean, fecthOnline?: boolean) {
     Switcher._snapshot = loadDomain(
       Switcher._options.snapshotLocation || '',
       Switcher._context.environment,
     );
     if (
       Switcher._snapshot?.data.domain.version == 0 &&
-      !Switcher._options.offline
+      (fecthOnline || !Switcher._options.offline)
     ) {
       await Switcher.checkSnapshot();
     }
@@ -195,6 +191,30 @@ export class Switcher {
     }
   }
 
+  /**
+   * Schedule Snapshot auto update.
+   * It can also be configured using SwitcherOptions 'snapshotAutoUpdateInterval' when
+   * building context
+   *
+   * @param interval in ms
+   */
+  static scheduleSnapshotAutoUpdate(interval?: number) {
+    if (interval) {
+      Switcher._options.snapshotAutoUpdateInterval = interval;
+    }
+
+    if (Switcher._options.snapshotAutoUpdateInterval && Switcher._options.snapshotAutoUpdateInterval > 0) {
+      SnapshotAutoUpdater.schedule(Switcher._options.snapshotAutoUpdateInterval, this.checkSnapshot);
+    }
+  }
+
+  /**
+   * Terminates Snapshot Auto Update
+   */
+  static terminateSnapshotAutoUpdate() {
+    SnapshotAutoUpdater.terminate();
+  }
+
   /**
    * Verifies if switchers are properly configured
    *
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index 3b1998c..c82fb94 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -26,6 +26,7 @@ export interface SwitcherOptions {
   offline?: boolean;
   logger?: boolean;
   snapshotLocation?: string;
+  snapshotAutoUpdateInterval?: number;
   silentMode?: boolean;
   retryAfter?: string;
   regexMaxBlackList?: number;
diff --git a/test/playground/index.ts b/test/playground/index.ts
index 2539276..0958bf3 100644
--- a/test/playground/index.ts
+++ b/test/playground/index.ts
@@ -15,7 +15,9 @@ let switcher;
  */
 function setupSwitcher(offline: boolean) {
     Switcher.buildContext({ url, apiKey, domain, component, environment }, { offline, logger: true });
-    Switcher.loadSnapshot();
+    Switcher.loadSnapshot()
+        .then(() => console.log('Snapshot loaded'))
+        .catch(() => console.log('Failed to load Snapshot'));
 }
 
 // Requires online API
@@ -110,4 +112,19 @@ const testWatchSnapshot = () => {
         (err: any) => console.log(err));
 };
 
-testSimpleAPICall(true);
\ No newline at end of file
+// Requires online API
+const testSnapshotAutoUpdate = () => {
+    Switcher.buildContext({ url, apiKey, domain, component, environment }, 
+        { offline: true, logger: true, snapshotAutoUpdateInterval: 3000 });
+
+    Switcher.loadSnapshot();
+    const switcher = Switcher.factory();
+
+    setInterval(async () => {
+        const time = Date.now();
+        await switcher.isItOn(SWITCHER_KEY, [checkValue('user_1')]);
+        console.log(Switcher.getLogger(SWITCHER_KEY), `executed in ${Date.now() - time}ms`);
+    }, 2000);
+};
+
+testSnapshotAutoUpdate();
\ No newline at end of file
diff --git a/test/switcher-snapshot.test.ts b/test/switcher-snapshot.test.ts
index ae0d512..b2a98a2 100644
--- a/test/switcher-snapshot.test.ts
+++ b/test/switcher-snapshot.test.ts
@@ -2,7 +2,7 @@ import { describe, it, afterAll, beforeEach } from 'https://deno.land/std@0.188.
 import { assertRejects, assertFalse, assertExists } from 'https://deno.land/std@0.188.0/testing/asserts.ts';
 import { delay } from 'https://deno.land/std@0.177.0/async/delay.ts';
 import { existsSync } from 'https://deno.land/std@0.110.0/fs/mod.ts';
-import { given, givenError, tearDown, generateAuth, generateStatus, assertTrue } from './helper/utils.ts';
+import { given, givenError, tearDown, generateAuth, generateStatus, assertTrue, WaitSafe } from './helper/utils.ts';
 
 import { Switcher } from '../mod.ts';
 import { SwitcherContext } from '../src/types/index.d.ts';
@@ -16,6 +16,9 @@ describe('E2E test - Switcher offline - Snapshot:', function () {
   const dataBuffer = Deno.readTextFileSync('./snapshot/dev.json');
   const dataJSON = dataBuffer.toString();
 
+  const dataBufferV2 = Deno.readTextFileSync('./snapshot/dev_v2.json');
+  const dataJSONV2 = dataBufferV2.toString();
+
   beforeEach(function() {
     Switcher.unloadSnapshot();
     
@@ -42,7 +45,7 @@ describe('E2E test - Switcher offline - Snapshot:', function () {
   });
 
   it('should NOT update snapshot - Too many requests at checkSnapshotVersion', testSettings, async function () {
-    //give
+    //given
     given('POST@/criteria/auth', generateAuth(token, 5));
     given('GET@/criteria/snapshot_check/:version', null, 429);
     
@@ -73,7 +76,7 @@ describe('E2E test - Switcher offline - Snapshot:', function () {
   it('should update snapshot', testSettings, async function () {
     await delay(2000);
 
-    //give
+    //given
     given('POST@/criteria/auth', generateAuth(token, 5));
     given('GET@/criteria/snapshot_check/:version', generateStatus(false));
     given('POST@/graphql', JSON.parse(dataJSON));
@@ -91,6 +94,39 @@ describe('E2E test - Switcher offline - Snapshot:', function () {
     Switcher.unloadSnapshot();
   });
 
+  it('should auto update snapshot every 1000ms', testSettings, async function () {
+    await delay(3000);
+
+    //given
+    given('POST@/criteria/auth', generateAuth(token, 5));
+    given('GET@/criteria/snapshot_check/:version', generateStatus(false));
+    given('POST@/graphql', JSON.parse(dataJSON));
+
+    //test
+    Switcher.buildContext(contextSettings, {
+      snapshotLocation: 'generated-snapshots/',
+      offline: true,
+      snapshotAutoUpdateInterval: 500
+    });
+
+    //optional (already set in the buildContext)
+    Switcher.scheduleSnapshotAutoUpdate(1000);
+    
+    await Switcher.loadSnapshot(false, true);
+    
+    const switcher = Switcher.factory();
+    assertFalse(await switcher.isItOn('FF2FOR2030'));
+    
+    //given new version
+    given('POST@/graphql', JSON.parse(dataJSONV2));
+
+    WaitSafe.limit(2000);
+    await WaitSafe.wait();
+    assertTrue(await switcher.isItOn('FF2FOR2030'));
+
+    Switcher.terminateSnapshotAutoUpdate();
+  });
+
   it('should NOT update snapshot', testSettings, async function () {
     await delay(2000);
 
diff --git a/test/switcher-watch-snapshot.test.ts b/test/switcher-watch-snapshot.test.ts
index d95a284..945d437 100644
--- a/test/switcher-watch-snapshot.test.ts
+++ b/test/switcher-watch-snapshot.test.ts
@@ -2,10 +2,9 @@
 import { describe, it, afterAll, beforeEach } from 'https://deno.land/std@0.188.0/testing/bdd.ts';
 import { assertEquals, assertFalse } from 'https://deno.land/std@0.188.0/testing/asserts.ts';
 import { existsSync } from 'https://deno.land/std@0.110.0/fs/mod.ts';
-import { assertTrue } from './helper/utils.ts';
+import { assertTrue, WaitSafe } from './helper/utils.ts';
 
 import { Switcher } from '../mod.ts';
-import { WaitSafe } from './helper/utils.ts';
 
 const updateSwitcher = (status: boolean) => {
   const dataBuffer = Deno.readTextFileSync('./snapshot/dev.json');