wip: adding Command pattern

__tests__/behavioral/ProcessChain.spec.ts

@@ -37,14 +37,14 @@ import {
 } from 'vitest'
 
 import {
-  ProcessChain,
+  RequestChain,
 } from '@/index'
 
 type Data = {
   prop: number
 }
 
-class ProcessableChain extends ProcessChain<Data> {
+class ProcessableChain extends RequestChain<Data> {
   isProcessable(data: Data): boolean {
     return 'prop' in data
   }
@@ -54,7 +54,7 @@ class ProcessableChain extends ProcessChain<Data> {
   }
 }
 
-class UnprocessableChain extends ProcessChain<Data> {
+class UnprocessableChain extends RequestChain<Data> {
   isProcessable(data: Data): boolean {
     return !('prop' in data)
   }
@@ -64,7 +64,7 @@ class UnprocessableChain extends ProcessChain<Data> {
   }
 }
 
-describe('ProcessChain', () => {
+describe('RequestChain', () => {
   it('count the links in the chain', () => {
     const a = new ProcessableChain()
     const b = new ProcessableChain()

src/behavioral/Command.ts

@@ -0,0 +1,69 @@
+/**
+ * BSD 3-Clause License
+ *
+ * Copyright © 2023, Daniel Jonathan <daniel at cosmicmind dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS'
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES LOSS OF USE, DATA, OR PROFITS OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import {
+  Optional,
+} from '@cosmicmind/foundationjs'
+
+/**
+ * @module Command
+ */
+
+export type Command = {
+  /**
+   * Executes the method.
+   *
+   * @return {void} Returns nothing.
+   */
+  execute(): void
+}
+
+export type Operable = {
+  execute(command: Command): void
+}
+
+export class Operation implements Operable {
+  protected commands: Command[]
+
+  constructor() {
+    this.commands = []
+  }
+
+  execute(command: Command): void {
+    command.execute()
+    this.commands.push(command)
+  }
+
+  pop(): Optional<Command> {
+    return this.commands.pop()
+  }
+}

src/behavioral/ProcessChain.ts → src/behavioral/RequestChain.ts

@@ -31,20 +31,20 @@
  */
 
 /**
- * @module ProcessChain
+ * @module RequestChain
  */
 
 import {
-  Nullable,
+  Optional,
 } from '@cosmicmind/foundationjs'
 
 export type Chainable<T> = {
   /**
    * Retrieves the next value in the chain.
    *
-   * @return {Nullable<Chainable<T>>} The next value in the chain, or null if there is none.
+   * @return {Optional<Chainable<T>>} The next value in the chain, or undefined if there is none.
    */
-  get next(): Nullable<Chainable<T>>
+  get next(): Optional<Chainable<T>>
 
   /**
    * Executes the method with the given arguments.
@@ -63,20 +63,16 @@ export type Chainable<T> = {
   isProcessable(...args: T[]): void
 }
 
-export abstract class ProcessChain<T> implements Chainable<T> {
-  protected _next?: Nullable<Chainable<T>>
+export abstract class RequestChain<T> implements Chainable<T> {
+  protected _next: Optional<Chainable<T>>
 
   /**
    * Retrieves the next item in the chain.
    *
-   * @returns {Nullable<Chainable<T>>} The next item in the chain, or null if there isn't a next item.
+   * @returns {Optional<Chainable<T>>} The next item in the chain, or undefined if there isn't a next item.
    */
-  get next(): Nullable<Chainable<T>> {
-    return this._next || null
-  }
-
-  constructor() {
-    this._next = null
+  get next(): Optional<Chainable<T>> {
+    return this._next
   }
 
   /**
@@ -95,7 +91,7 @@ export abstract class ProcessChain<T> implements Chainable<T> {
    * @returns {void}
    */
   clear(): void {
-    this._next = null
+    this._next = undefined
   }
 
   /**

src/behavioral/index.ts

@@ -30,6 +30,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+export * from '@/behavioral/Observable'
 export * from '@/behavioral/Observable'
 export * from '@/behavioral/Plugin'
-export * from '@/behavioral/ProcessChain'
+export * from '@/behavioral/RequestChain'