Merge pull request #127 from robonen/stdlib-fix-reusing

refactor(core/stdlib): update state machine classes to use consistent property names and improve type safety

core/stdlib/src/patterns/behavioral/StateMachine/async.ts

@@ -1,3 +1,4 @@
+import { isString } from '../../../types';
 import { BaseStateMachine } from './base';
 import type { AsyncStateNodeConfig, ExtractStates, ExtractEvents } from './types';
 
@@ -24,33 +25,33 @@ export class AsyncStateMachine<
    * @returns The current state after processing the event
    */
   async send(event: Events): Promise<States> {
-    const stateNode = this._states[this._current];
+    const stateNode = this.states[this.currentState];
 
     if (!stateNode?.on)
-      return this._current;
+      return this.currentState;
 
     const transition = stateNode.on[event];
 
     if (transition === undefined)
-      return this._current;
+      return this.currentState;
 
     let target: string;
 
-    if (typeof transition === 'string') {
+    if (isString(transition)) {
       target = transition;
     } else {
-      if (transition.guard && !(await transition.guard(this._context)))
+      if (transition.guard && !(await transition.guard(this.context)))
-        return this._current;
+        return this.currentState;
 
-      await transition.action?.(this._context);
+      await transition.action?.(this.context);
       target = transition.target;
     }
 
-    await stateNode.exit?.(this._context);
+    await stateNode.exit?.(this.context);
-    this._current = target as States;
+    this.currentState = target as States;
-    await this._states[this._current]?.entry?.(this._context);
+    await this.states[this.currentState]?.entry?.(this.context);
 
-    return this._current;
+    return this.currentState;
   }
 
   /**
@@ -59,7 +60,7 @@ export class AsyncStateMachine<
    * @param event - Event to check
    */
   async can(event: Events): Promise<boolean> {
-    const stateNode = this._states[this._current];
+    const stateNode = this.states[this.currentState];
 
     if (!stateNode?.on)
       return false;
@@ -69,8 +70,8 @@ export class AsyncStateMachine<
     if (transition === undefined)
       return false;
 
-    if (typeof transition !== 'string' && transition.guard)
+    if (!isString(transition) && transition.guard)
-      return await transition.guard(this._context);
+      return await transition.guard(this.context);
 
     return true;
   }

core/stdlib/src/patterns/behavioral/StateMachine/base.ts

@@ -12,28 +12,25 @@ export class BaseStateMachine<
   Context,
   NodeConfig,
 > {
-  protected _current: States;
+  protected currentState: States;
-  protected _context: Context;
+  protected readonly states: Record<string, NodeConfig>;
-  protected _states: Record<string, NodeConfig>;
+
+  /** Machine context */
+  readonly context: Context;
 
   constructor(
     initial: States,
     states: Record<string, NodeConfig>,
     context: Context,
   ) {
-    this._current = initial;
+    this.currentState = initial;
-    this._context = context;
+    this.context = context;
-    this._states = states;
+    this.states = states;
   }
 
   /** Current state of the machine */
   get current(): States {
-    return this._current;
+    return this.currentState;
-  }
-
-  /** Machine context */
-  get context(): Context {
-    return this._context;
   }
 
   /**
@@ -42,6 +39,6 @@ export class BaseStateMachine<
    * @param state - State to check
    */
   matches(state: States): boolean {
-    return this._current === state;
+    return this.currentState === state;
   }
 }

core/stdlib/src/patterns/behavioral/StateMachine/sync.ts

@@ -1,3 +1,4 @@
+import { isString } from '../../../types';
 import { BaseStateMachine } from './base';
 import type { SyncStateNodeConfig, ExtractStates, ExtractEvents } from './types';
 
@@ -24,33 +25,33 @@ export class StateMachine<
    * @returns The current state after processing the event
    */
   send(event: Events): States {
-    const stateNode = this._states[this._current];
+    const stateNode = this.states[this.currentState];
 
     if (!stateNode?.on)
-      return this._current;
+      return this.currentState;
 
     const transition = stateNode.on[event];
 
     if (transition === undefined)
-      return this._current;
+      return this.currentState;
 
     let target: string;
 
-    if (typeof transition === 'string') {
+    if (isString(transition)) {
       target = transition;
     } else {
-      if (transition.guard && !transition.guard(this._context))
+      if (transition.guard && !transition.guard(this.context))
-        return this._current;
+        return this.currentState;
 
-      transition.action?.(this._context);
+      transition.action?.(this.context);
       target = transition.target;
     }
 
-    stateNode.exit?.(this._context);
+    stateNode.exit?.(this.context);
-    this._current = target as States;
+    this.currentState = target as States;
-    this._states[this._current]?.entry?.(this._context);
+    this.states[this.currentState]?.entry?.(this.context);
 
-    return this._current;
+    return this.currentState;
   }
 
   /**
@@ -59,7 +60,7 @@ export class StateMachine<
    * @param event - Event to check
    */
   can(event: Events): boolean {
-    const stateNode = this._states[this._current];
+    const stateNode = this.states[this.currentState];
 
     if (!stateNode?.on)
       return false;
@@ -69,8 +70,8 @@ export class StateMachine<
     if (transition === undefined)
       return false;
 
-    if (typeof transition !== 'string' && transition.guard)
+    if (!isString(transition) && transition.guard)
-      return transition.guard(this._context);
+      return transition.guard(this.context);
 
     return true;
   }