feat(providers): add streaming stt providers

test/helpers/stt-live-audio.ts

@@ -0,0 +1,77 @@
+const DEFAULT_ELEVENLABS_BASE_URL = "https://api.elevenlabs.io";
+const DEFAULT_ELEVENLABS_VOICE_ID = "pMsXgVXv3BLzUgSXRplE";
+const DEFAULT_ELEVENLABS_TTS_MODEL_ID = "eleven_multilingual_v2";
+
+export function normalizeTranscriptForMatch(value: string): string {
+  return value.toLowerCase().replace(/[^a-z0-9]+/g, "");
+}
+
+export async function waitForLiveExpectation(expectation: () => void, timeoutMs = 30_000) {
+  const started = Date.now();
+  let lastError: unknown;
+  while (Date.now() - started < timeoutMs) {
+    try {
+      expectation();
+      return;
+    } catch (error) {
+      lastError = error;
+      await new Promise((resolve) => setTimeout(resolve, 100));
+    }
+  }
+  throw lastError;
+}
+
+export async function synthesizeElevenLabsLiveSpeech(params: {
+  text: string;
+  apiKey: string;
+  outputFormat: "mp3_44100_128" | "ulaw_8000";
+  timeoutMs?: number;
+}): Promise<Buffer> {
+  const baseUrl = process.env.ELEVENLABS_BASE_URL?.trim() || DEFAULT_ELEVENLABS_BASE_URL;
+  const voiceId = process.env.ELEVENLABS_LIVE_VOICE_ID?.trim() || DEFAULT_ELEVENLABS_VOICE_ID;
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), params.timeoutMs ?? 30_000);
+  try {
+    const url = new URL(`${baseUrl.replace(/\/+$/, "")}/v1/text-to-speech/${voiceId}`);
+    url.searchParams.set("output_format", params.outputFormat);
+    const response = await fetch(url, {
+      method: "POST",
+      headers: {
+        "xi-api-key": params.apiKey,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({
+        text: params.text,
+        model_id: DEFAULT_ELEVENLABS_TTS_MODEL_ID,
+        voice_settings: {
+          stability: 0.5,
+          similarity_boost: 0.75,
+          style: 0,
+          use_speaker_boost: true,
+          speed: 1,
+        },
+      }),
+      signal: controller.signal,
+    });
+    if (!response.ok) {
+      throw new Error(`ElevenLabs live TTS failed (${response.status})`);
+    }
+    return Buffer.from(await response.arrayBuffer());
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+export async function streamAudioForLiveTest(params: {
+  audio: Buffer;
+  sendAudio: (chunk: Buffer) => void;
+  chunkSize?: number;
+  delayMs?: number;
+}) {
+  const chunkSize = params.chunkSize ?? 160;
+  const delayMs = params.delayMs ?? 5;
+  for (let offset = 0; offset < params.audio.byteLength; offset += chunkSize) {
+    params.sendAudio(params.audio.subarray(offset, offset + chunkSize));
+    await new Promise((resolve) => setTimeout(resolve, delayMs));
+  }
+}