fix: allow multiple plugins to "register" the same hook

Allows multiple plugins to execute the same hook(s)

README.md

@@ -1,5 +1,5 @@
 # Hijacker
-[![npm](https://img.shields.io/npm/v/hijacker.svg)](https://www.npmjs.com/package/hijacker)
+[![npm](https://img.shields.io/npm/v/@hijacker/core.svg)](https://www.npmjs.com/package/@hijacker/core)
 [![Build Status](https://github.com/travis-w/hijacker/actions/workflows/workflow.yml/badge.svg)](https://github.com/travis-w/hijacker/actions/workflows/workflow.yml)
 [![Coverage Status](https://coveralls.io/repos/github/travis-w/hijacker/badge.svg?branch=master)](https://coveralls.io/github/travis-w/hijacker?branch=master)
 

src/utils/HookManager.spec.ts

@@ -30,15 +30,6 @@ describe('HookManager', () => {
     expect(hookManager.hooks['REQUEST']).toEqual([]);
   });
 
-  it('should not allow registering hook if one with same name already exists', () => {
-    expect.assertions(1);
-
-    hookManager.registerHook('REQUEST');
-    expect(() => {
-      hookManager.registerHook('REQUEST');
-    }).toThrow('A hook already exists with that name');
-  });
-
   it('should allow registering handlers', () => {
     expect.assertions(1);
 
@@ -53,7 +44,7 @@ describe('HookManager', () => {
 
     expect(() => {
       hookManager.registerHandler('REQUEST', () => null);
-    }).toThrow('No hook with that name exists');
+    }).toThrow('Can\'t register handler for non-existant hook \'REQUEST\'');
   });
 
   it('should execute handler on value', async () => {
@@ -83,7 +74,7 @@ describe('HookManager', () => {
     expect.assertions(1);
 
     expect(hookManager.executeHook('REQUEST', () => null))
-      .rejects.toThrow('No hook with that name exists');
+      .rejects.toThrow('Can\'t execute non-existant hook \'REQUEST\'');
   });
 
   it('should execute handlers in order they were registered', async () => {
@@ -103,7 +94,7 @@ describe('HookManager', () => {
 
     expect(() => {
       hookManager.executeSyncHook('REQUEST', () => null);
-    }).toThrow('No hook with that name exists');
+    }).toThrow('Can\'t execute non-existant hook \'REQUEST\'');
   });
 
   it('should throw error when async handler registered for a sync hook', () => {

src/utils/HookManager.ts

@@ -30,18 +30,16 @@ export class HookManager {
   registerHook(hookName: string) {
     this.logger.log('DEBUG', '[HookManager]', 'registerHook');
 
-    if (hookName in this.hooks) {
-      throw new Error('A hook already exists with that name');
+    if (hookName in this.hooks === false) {
+      this.hooks[hookName] = [];
     }
-
-    this.hooks[hookName] = [];
   }
 
   registerHandler(hookName: string, handler: Handler) {
     this.logger.log('DEBUG', '[HookManager]', 'registerHandler');
 
     if (hookName in this.hooks === false) {
-      throw new Error('No hook with that name exists');
+      throw new Error(`Can't register handler for non-existant hook '${hookName}'`);
     }
 
     this.hooks[hookName].push(handler);
@@ -51,7 +49,7 @@ export class HookManager {
     this.logger.log('DEBUG', '[HookManager]', 'executeHook');
 
     if (hookName in this.hooks === false) {
-      throw new Error('No hook with that name exists');
+      throw new Error(`Can't execute non-existant hook '${hookName}'`);
     }
 
     return await this.hooks[hookName].reduce(async (acc, cur) => cur(await acc), initialVal);
@@ -61,7 +59,7 @@ export class HookManager {
     this.logger.log('DEBUG', '[HookManager]', 'executeSyncHook');
 
     if (hookName in this.hooks === false) {
-      throw new Error('No hook with that name exists');
+      throw new Error(`Can't execute non-existant hook '${hookName}'`);
     }
 
     return this.hooks[hookName].reduce((acc, cur) => {