Streams

You can handle streams in Evalite by returning any async iterable (including a ReadableStream) from your task. This means you can test functions like the AI SDK streamText function easily:

import { evalite } from "evalite";
import { streamText } from "ai";
import { openai } from "@ai-sdk/openai";
import { Factuality } from "autoevals";

evalite("My Eval", {
  data: async () => {
    return [{ input: "What is the capital of France?", expected: "Paris" }];
  },
  task: async (input) => {
    const result = await streamText({
      model: openai("your-model"),
      system: `Answer the question concisely.`,
      prompt: input,
    });

    return result.textStream;
  },
  scorers: [Factuality],
});