Update code to typescript

src/tts/espeak.ts

@@ -0,0 +1,33 @@
+import { spawn } from "node:child_process";
+import { BaseEngine, type VoiceParams } from "./BaseEngine.js";
+
+export class EspeakEngine extends BaseEngine {
+  constructor() {
+    super("espeak", "ESpeak", "wav");
+  }
+
+  override getDefaultVoice(): string {
+    return "en";
+  }
+
+  override validateVoice(_voice: string): boolean {
+    return true;
+  }
+
+  override async getSpeechFile(
+    text: string,
+    filepath: string,
+    voice: string = this.getDefaultVoice(),
+    _params: VoiceParams = {},
+  ): Promise<string> {
+    return new Promise((resolve, reject) => {
+      const proc = spawn("espeak", ["-v", voice, "-w", filepath, "--stdin"]);
+      proc.on("error", reject);
+      proc.on("close", (code) => {
+        if (code === 0) resolve(filepath);
+        else reject(new Error(`espeak exited with code ${code}`));
+      });
+      proc.stdin.end(text);
+    });
+  }
+}