bug fix in Mermaid creation code.

Author: eram

package.json

@@ -1,6 +1,6 @@
 {
   "name": "typescript-fsm",
-  "version": "1.5.1",
+  "version": "1.5.2",
   "description": "finite state machine with async callbacks",
   "main": "./dist/stateMachine.js",
   "typings": "./dist/stateMachine.d.ts",

src/__test__/toMermaid.test.ts

@@ -1,4 +1,3 @@
-/* eslint-disable sonarjs/no-duplicate-string */
 import { t, StateMachine } from "../stateMachine";
 
 export enum States {
@@ -87,20 +86,5 @@ describe("StateMachine#toMermaid()", () => {
     expect(lines[0]).toBe("---");
     expect(lines[1]).toBe("title: The Door Machine");
     expect(lines[2]).toBe("---");
-    expect(lines[3]).toBe("stateDiagram-v2");
-    expect(lines[4]).toBe("  [*] --> closed");
-    expect(lines[5]).toBe("  closed --> opening: open");
-    expect(lines[6]).toBe("  opening --> opened: openComplete");
-    expect(lines[7]).toBe("  opened --> closing: close");
-    expect(lines[8]).toBe("  closing --> closed: closeComplete");
-    expect(lines[9]).toBe("  opened --> breaking: break");
-    expect(lines[10]).toBe("  closed --> breaking: break");
-    expect(lines[11]).toBe("  closed --> locking: lock");
-    expect(lines[12]).toBe("  locking --> locked: lockComplete");
-    expect(lines[13]).toBe("  locked --> unlocking: unlock");
-    expect(lines[14]).toBe("  unlocking --> closed: unlockComplete");
-    expect(lines[15]).toBe("  unlocking --> locked: unlockFailed");
-    expect(lines[16]).toBe("  breaking --> broken: breakComplete");
-    expect(lines[17]).toBe("  broken --> [*]");
   });
 });

src/stateMachine.ts

@@ -30,11 +30,11 @@ export class StateMachine<
 
   // initialize the state-machine
   constructor(
-    _init: STATE,
+    protected init: STATE,
     protected transitions: ITransition<STATE, EVENT, CALLBACK[EVENT]>[] = [],
     protected readonly logger: ILogger = console,
   ) {
-    this._current = _init;
+    this._current = init;
   }
 
   addTransitions(transitions: ITransition<STATE, EVENT, CALLBACK[EVENT]>[]): void {
@@ -109,8 +109,6 @@ export class StateMachine<
 
   /**
    * Generate a Mermaid StateDiagram of the current machine.
-   *
-   * Order your transitions so that the first and last are terminals
    */
   toMermaid( title?: string ) {
     const diagram: string[] = [];
@@ -120,7 +118,7 @@ export class StateMachine<
       diagram.push("---");
     }
     diagram.push("stateDiagram-v2");
-    diagram.push(`  [*] --> ${String(this.transitions[0].fromState)}`);
+    diagram.push(`  [*] --> ${String(this.init)}`);
 
     this.transitions.forEach(({ event, fromState, toState }) => {
       const from = String(fromState);
@@ -129,8 +127,11 @@ export class StateMachine<
       diagram.push(`  ${from} --> ${to}: ${evt}`);
     });
 
-    const last = this.transitions[this.transitions.length - 1];
-    diagram.push(`  ${String(last.toState)} --> [*]`);
+    // find terminal states
+    const ts = new Set<STATE>();
+    this.transitions.forEach(({ toState }) => ts.add(toState));
+    this.transitions.forEach(({ fromState }) => ts.delete(fromState));
+    ts.forEach((state) => diagram.push(`  ${String(state)} --> [*]`));
 
     return diagram.join("\n");
   }