feat: Dynamic String Prompt for REPL

examples/repl-dynamic-prompt.ts

@@ -0,0 +1,21 @@
+import { command, program } from "../src/index.js";
+
+const app = program({
+  prompt: () => `[${new Date().toLocaleTimeString()}] > `,
+});
+
+async function rng(bounds: [number, number]) {
+  const [min, max] = bounds;
+  return Math.floor(Math.random() * (max - min + 1)) + min;
+}
+
+const dice = app.add(
+  command("roll")
+    .option("min", { default: 1 })
+    .option("max", { default: 6 })
+    .action(async (args) => {
+      console.log(await rng([args.min, args.max]));
+    }),
+);
+
+app.runOrRepl();

src/program.ts

@@ -31,7 +31,7 @@ type ProgramOptions = {
    *
    * Defaults to `> `.
    */
-  prompt?: string;
+  prompt?: string | (() => string);
 
   /**
    * Whether or not to add a global help command that displays an overview of

src/repl.ts

@@ -42,8 +42,9 @@ export class Repl {
    * @private
    */
   public async start() {
+    const { prompt } = this.program.options;
     this.server = nodeRepl.start({
-      prompt: this.program.options.prompt,
+      prompt: typeof prompt === "function" ? prompt() : prompt,
       eval: this.eval.bind(this),
       completer: this.completer.bind(this),
       ignoreUndefined: true,