chore: drop event hook (#3565)

## About the changes
Ref:
https://docs.getunleash.io/reference/deploy/configuring-unleash#further-customization
> **eventHook** (`function(event, data)`) - (_deprecated in Unleash 4.3_
in favor of the [Webhook addon](../addons/webhook.md)) If provided, this
function will be invoked whenever a feature is mutated. The possible
values for `event` are `'feature-created'`, `'feature-archived'` and
`'feature-revived'`. The `data` argument contains information about the
mutation. Its fields are `type` (string) - the event type (same as
`event`); `createdBy` (string) - the user who performed the mutation;
`data` - the contents of the change. The contents in `data` differs
based on the event type; For `'feature-archived'` and
`'feature-revived'`, the only field will be `name` - the name of the
feature. For `'feature-created'` the data follows a schema defined in
the code
[here](https://github.com/Unleash/unleash/blob/7b7f0b84e8cddd5880dcf29c231672113224b9a7/src/lib/schema/feature-schema.ts#L77).
See an [api here](/reference/api/legacy/unleash/admin/events).


Related to: #1265

src/lib/__snapshots__/create-config.test.ts.snap

@@ -61,7 +61,6 @@ exports[`should create default config 1`] = `
     "_maxListeners": undefined,
     Symbol(kCapture): false,
   },
-  "eventHook": undefined,
   "experimental": {
     "externalResolver": {
       "isEnabled": [Function],

src/lib/create-config.ts

@@ -45,13 +45,14 @@ import {
 import FlagResolver from './util/flag-resolver';
 import { validateOrigins } from './util/validateOrigin';
 
-const safeToUpper = (s: string) => (s ? s.toUpperCase() : s);
+const safeToUpper = (s?: string) => (s ? s.toUpperCase() : s);
 
 export function authTypeFromString(
     s?: string,
     defaultType: IAuthType = IAuthType.OPEN_SOURCE,
 ): IAuthType {
-    return IAuthType[safeToUpper(s)] || defaultType;
+    const upperS = safeToUpper(s);
+    return upperS && IAuthType[upperS] ? IAuthType[upperS] : defaultType;
 }
 
 function mergeAll<T>(objects: Partial<T>[]): T {
@@ -93,7 +94,7 @@ function loadClientCachingOptions(
 
     return mergeAll([
         defaultClientCachingOptions,
-        options.clientFeatureCaching,
+        options.clientFeatureCaching || {},
         envs,
     ]);
 }
@@ -249,7 +250,10 @@ const formatServerOptions = (
     };
 };
 
-const loadTokensFromString = (tokenString: String, tokenType: ApiTokenType) => {
+const loadTokensFromString = (
+    tokenString: String | undefined,
+    tokenType: ApiTokenType,
+) => {
     if (!tokenString) {
         return [];
     }
@@ -297,7 +301,7 @@ const loadEnvironmentEnableOverrides = () => {
 };
 
 const parseCspConfig = (
-    cspConfig: ICspDomainOptions,
+    cspConfig?: ICspDomainOptions,
 ): ICspDomainConfig | undefined => {
     if (!cspConfig) {
         return undefined;
@@ -366,12 +370,12 @@ export function createConfig(options: IUnleashOptions): IUnleashConfig {
         defaultDbOptions,
         dbPort(extraDbOptions),
         dbPort(fileDbOptions),
-        options.db,
+        options.db || {},
     ]);
 
     const session: ISessionOption = mergeAll([
         defaultSessionOption,
-        options.session,
+        options.session || {},
     ]);
 
     const logLevel =
@@ -381,12 +385,12 @@ export function createConfig(options: IUnleashOptions): IUnleashConfig {
 
     const server: IServerOption = mergeAll([
         defaultServerOption,
-        formatServerOptions(options.server),
+        formatServerOptions(options.server) || {},
     ]);
 
     const versionCheck: IVersionOption = mergeAll([
         defaultVersionOption,
-        options.versionCheck,
+        options.versionCheck || {},
     ]);
 
     const initApiTokens = loadInitApiTokens();
@@ -403,15 +407,15 @@ export function createConfig(options: IUnleashOptions): IUnleashConfig {
 
     const importSetting: IImportOption = mergeAll([
         defaultImport,
-        options.import,
+        options.import || {},
     ]);
 
     const experimental = loadExperimental(options);
     const flagResolver = new FlagResolver(experimental);
 
     const ui = loadUI(options);
 
-    const email: IEmailOption = mergeAll([defaultEmail, options.email]);
+    const email: IEmailOption = mergeAll([defaultEmail, options.email || {}]);
 
     let listen: IListeningPipe | IListeningHost;
     if (server.pipe) {
@@ -483,7 +487,6 @@ export function createConfig(options: IUnleashOptions): IUnleashConfig {
         disableLegacyFeaturesApi,
         preHook: options.preHook,
         preRouterHook: options.preRouterHook,
-        eventHook: options.eventHook,
         enterpriseVersion: options.enterpriseVersion,
         eventBus: new EventEmitter(),
         environmentEnableOverrides,

src/lib/internals.ts

@@ -1,6 +1,5 @@
 export * from './logger';
 export * from './metrics';
-export * from './event-hook';
 export * from './metric-events';
 export * from './default-custom-auth-deny-all';
 export * from './addons';

src/lib/server-impl.test.ts

@@ -93,20 +93,6 @@ test('should call preRouterHook', async () => {
     await stop();
 });
 
-test('should call eventHook', async () => {
-    let called = 0;
-    const config = createTestConfig({
-        server: { port: 0 },
-        eventHook: () => {
-            called++;
-        },
-    });
-    const { stop } = await start(config);
-    eventStore.emit('feature-created', {});
-    expect(called === 1).toBe(true);
-    await stop();
-});
-
 test('should auto-create server on start()', async () => {
     const { server, stop } = await start(
         createTestConfig({ server: { port: 0 } }),

src/lib/server-impl.ts

@@ -7,7 +7,6 @@ import { createMetricsMonitor } from './metrics';
 import { createStores } from './db';
 import { createServices, scheduleServices } from './services';
 import { createConfig } from './create-config';
-import { addEventHook } from './event-hook';
 import registerGracefulShutdown from './util/graceful-shutdown';
 import { createDb } from './db/db-pool';
 import sessionDb from './middleware/session-db';
@@ -70,9 +69,6 @@ async function createApp(
     }
     const app = await getApp(config, stores, services, unleashSession, db);
 
-    if (typeof config.eventHook === 'function') {
-        addEventHook(config.eventHook, stores.eventStore);
-    }
     await metricsMonitor.startMonitoring(
         config,
         stores,

src/lib/types/option.ts

@@ -4,8 +4,6 @@ import { ILegacyApiTokenCreate } from './models/api-token';
 import { IFlagResolver, IExperimentalOptions, IFlags } from './experimental';
 import SMTPTransport from 'nodemailer/lib/smtp-transport';
 
-export type EventHook = (eventName: string, data: object) => void;
-
 export interface ISSLOption {
     rejectUnauthorized: boolean;
     ca?: string;
@@ -112,7 +110,6 @@ export interface IUnleashOptions {
     enableOAS?: boolean;
     preHook?: Function;
     preRouterHook?: Function;
-    eventHook?: EventHook;
     enterpriseVersion?: string;
     disableLegacyFeaturesApi?: boolean;
     inlineSegmentConstraints?: boolean;
@@ -195,7 +192,6 @@ export interface IUnleashConfig {
     enableOAS: boolean;
     preHook?: Function;
     preRouterHook?: Function;
-    eventHook?: EventHook;
     enterpriseVersion?: string;
     eventBus: EventEmitter;
     disableLegacyFeaturesApi?: boolean;

src/lib/util/format-base-uri.ts

@@ -1,14 +1,14 @@
-export const formatBaseUri = (input: string): string => {
+export const formatBaseUri = (input?: string): string => {
     if (!input) return '';
     const firstChar = input[0];
     const lastChar = input[input.length - 1];
 
     if (firstChar === '/' && lastChar === '/') {
-        return input.substr(0, input.length - 1);
+        return input.substring(0, input.length - 1);
     }
 
     if (firstChar !== '/' && lastChar === '/') {
-        return `/${input.substr(0, input.length - 1)}`;
+        return `/${input.substring(0, input.length - 1)}`;
     }
 
     if (firstChar !== '/') {

src/lib/util/parseEnvVar.ts

@@ -1,4 +1,10 @@
-export function parseEnvVarNumber(envVar: string, defaultVal: number): number {
+export function parseEnvVarNumber(
+    envVar: string | undefined,
+    defaultVal: number,
+): number {
+    if (!envVar) {
+        return defaultVal;
+    }
     const parsed = Number.parseInt(envVar, 10);
 
     if (Number.isNaN(parsed)) {