Aggregated text delta is wrong

[mbuptivo]

Hi,
I'm having a problem with handling of 'thread.message.delta' events from openai agent. The first delta contains not only the first delta text, but accumulated text from next deltas, so then text is aggregated the result is wrong.
Ex:

DELTA 1: Hi ho <--- this should be "Hi " only
DELTA 2: how a
DELTA 3: re you
...
RESULT: Hi ho how are you...

Instead of:

DELTA 1: Hi
DELTA 2: how a
DELTA 3: re you
...
RESULT: Hi how are you...

It seems that this code for getting events:

ai-assistant-nodejs/src/agents/openai/OpenAIResponseHandler.ts

Line 23 in efc1733

for await (const event of this.assistantStream) {

Is incompatible with ".stream" method on thread runs here:

ai-assistant-nodejs/src/agents/openai/OpenAIAgent.ts

Line 105 in efc1733

const run = this.openai.beta.threads.runs.stream(this.openAiThread.id, {

As explained in this example form OpenAI: https://github.com/openai/openai-node/blob/master/examples/assistant-stream-raw.ts

	const run = this.openai.beta.threads.runs.stream(this.openAiThread.id, {
		assistant_id: this.assistant.id
	});

should instead be:

	const run = await this.openai.beta.threads.runs.create(this.openAiThread.id, {
		assistant_id: this.assistant.id,
		stream: true
	});

Notice that the returned object is of type Stream<OpenAI.Beta.Assistants.AssistantStreamEvent> instead.

If you want to use ".stream" instead, you should use ".on" events to get deltas. The advantage is that text is already aggregated and provided as "snapshot".