import { test } from "bun:test"; import assert from "node:assert/strict"; import { OpenAiRealtimeTranscriptionClient } from "./openaiRealtimeTranscriptionClient.ts";

test("OpenAiRealtimeTranscriptionClient sendSessionUpdate uses transcription session shape", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); let outbound = null; client.send = (payload) => { outbound = payload; }; client.sessionConfig = { inputAudioFormat: "pcm16", inputTranscriptionModel: "gpt-4o-mini-transcribe", inputTranscriptionLanguage: "en", inputTranscriptionPrompt: "Prefer English." };

client.sendSessionUpdate();

assert.ok(outbound); assert.equal(outbound.type, "session.update"); assert.equal(outbound.session.type, "transcription"); assert.equal(outbound.session.audio.input.format.type, "audio/pcm"); assert.equal(outbound.session.audio.input.format.rate, 24000); assert.equal(outbound.session.audio.input.turn_detection, null); assert.deepEqual(outbound.session.audio.input.noise_reduction, { type: "near_field" }); assert.equal(outbound.session.audio.input.transcription.model, "gpt-4o-mini-transcribe"); assert.equal(outbound.session.audio.input.transcription.language, "en"); assert.equal(outbound.session.audio.input.transcription.prompt, "Prefer English."); assert.deepEqual(outbound.session.include, ["item.input_audio_transcription.logprobs"]); });

test("OpenAiRealtimeTranscriptionClient keeps gpt-4o-transcribe as input transcription model", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); let outbound = null; client.send = (payload) => { outbound = payload; }; client.sessionConfig = { inputAudioFormat: "pcm16", inputTranscriptionModel: "gpt-4o-transcribe", inputTranscriptionLanguage: "en", inputTranscriptionPrompt: "Prefer English." };

client.sendSessionUpdate();

assert.ok(outbound); assert.equal(outbound.type, "session.update"); assert.equal(outbound.session.audio.input.transcription.model, "gpt-4o-transcribe"); });

test("OpenAiRealtimeTranscriptionClient normalizes unsupported ASR model values", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); let outbound = null; client.send = (payload) => { outbound = payload; }; client.sessionConfig = { inputAudioFormat: "pcm16", inputTranscriptionModel: "not-a-real-model", inputTranscriptionLanguage: "en", inputTranscriptionPrompt: "Prefer English." };

client.sendSessionUpdate();

assert.ok(outbound); assert.equal(outbound.type, "session.update"); assert.equal(outbound.session.audio.input.transcription.model, "gpt-4o-mini-transcribe"); });

test("OpenAiRealtimeTranscriptionClient maps G.711 input formats to OpenAI media descriptors", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); let outbound = null; client.send = (payload) => { outbound = payload; }; client.sessionConfig = { inputAudioFormat: "g711_ulaw", inputTranscriptionModel: "gpt-4o-mini-transcribe" };

client.sendSessionUpdate();

assert.ok(outbound); assert.equal(outbound.type, "session.update"); assert.equal(outbound.session.audio.input.format.type, "audio/pcmu"); });

test("OpenAiRealtimeTranscriptionClient emits transcript final flag by event type", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const received = []; client.on("transcript", (payload) => { received.push(payload); });

client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.delta", delta: "hello" }) ); client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.completed", transcript: "hello there" }) );

assert.equal(received.length, 2); assert.equal(received[0]?.text, "hello"); assert.equal(received[0]?.final, false); assert.equal(received[0]?.itemId, null); assert.equal(received[0]?.previousItemId, null); assert.equal(received[1]?.text, "hello there"); assert.equal(received[1]?.final, true); assert.equal(received[1]?.itemId, null); assert.equal(received[1]?.previousItemId, null); });

test("OpenAiRealtimeTranscriptionClient carries item linkage metadata for transcript events", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const received = []; client.on("transcript", (payload) => { received.push(payload); });

client.handleIncoming( JSON.stringify({ type: "input_audio_buffer.committed", item_id: "item_002", previous_item_id: "item_001" }) ); client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.completed", item_id: "item_002", transcript: "final transcript" }) );

assert.equal(received.length, 1); assert.equal(received[0]?.final, true); assert.equal(received[0]?.itemId, "item_002"); assert.equal(received[0]?.previousItemId, "item_001"); });

test("OpenAiRealtimeTranscriptionClient completed events emit logprobs", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const received: Record<string, unknown>[] = []; client.on("transcript", (payload: Record<string, unknown>) => { received.push(payload); });

const logprobs = [ { token: "hello", logprob: -0.3, bytes: null }, { token: " there", logprob: -0.7, bytes: null } ]; client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.completed", transcript: "hello there", item_id: "item_010", logprobs }) );

assert.equal(received.length, 1); assert.equal(received[0]?.final, true); assert.deepEqual(received[0]?.logprobs, logprobs); });

test("OpenAiRealtimeTranscriptionClient delta events emit null logprobs", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const received: Record<string, unknown>[] = []; client.on("transcript", (payload: Record<string, unknown>) => { received.push(payload); });

client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.delta", delta: "partial text" }) );

assert.equal(received.length, 1); assert.equal(received[0]?.final, false); assert.equal(received[0]?.logprobs, null); });

test("OpenAiRealtimeTranscriptionClient completed events without logprobs emit null", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const received: Record<string, unknown>[] = []; client.on("transcript", (payload: Record<string, unknown>) => { received.push(payload); });

client.handleIncoming( JSON.stringify({ type: "conversation.item.input_audio_transcription.completed", transcript: "no logprobs here", item_id: "item_011" }) );

assert.equal(received.length, 1); assert.equal(received[0]?.final, true); assert.equal(received[0]?.logprobs, null); });

test("OpenAiRealtimeTranscriptionClient emits speech start and stop events", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const speechEvents: Array<Record<string, unknown>> = []; client.on("speech_started", (payload: Record<string, unknown>) => { speechEvents.push({ phase: "started", ...payload }); }); client.on("speech_stopped", (payload: Record<string, unknown>) => { speechEvents.push({ phase: "stopped", ...payload }); });

client.handleIncoming( JSON.stringify({ type: "input_audio_buffer.speech_started", audio_start_ms: 120 }) ); client.handleIncoming( JSON.stringify({ type: "input_audio_buffer.speech_stopped", audio_end_ms: 860, item_id: "item_200" }) );

assert.equal(speechEvents.length, 2); assert.deepEqual(speechEvents[0], { phase: "started", eventType: "input_audio_buffer.speech_started", audioStartMs: 120, audioEndMs: null, itemId: null }); assert.deepEqual(speechEvents[1], { phase: "stopped", eventType: "input_audio_buffer.speech_stopped", audioStartMs: null, audioEndMs: 860, itemId: "item_200" }); });

test("OpenAiRealtimeTranscriptionClient buildRealtimeUrl uses transcription intent", () => { const client = new OpenAiRealtimeTranscriptionClient({ apiKey: "test-key" }); const url = client.buildRealtimeUrl(); assert.equal(url.includes("intent=transcription"), true); assert.equal(url.includes("model="), false); });