Testing

testResponses

Test agent handlers without calling the LLM by providing canned responses:

ctx.useAgent({
  systemPrompt: "...",
  model: "claude-sonnet-4-5-20250929",
  tools: [...ctx.darixTools],
  testResponses: ["Hello! How can I help?"],
})
await ctx.agent.run()

Responses are consumed in order. Each string becomes the agent's text output for that turn.

TestResponseFn

For dynamic test responses, provide a function instead of an array:

testResponses: async (message, bridge) => {
  bridge.onTextStart()
  bridge.onTextDelta("Test response")
  bridge.onTextEnd()
  return "Test response"
}

The bridge parameter gives control over text-level events, letting you simulate tool calls, reasoning steps, and multi-turn interactions. Returning a string emits it as a text block automatically.

Runtime-managed lifecycle

The runtime wraps your TestResponseFn with bridge.onRunStart() / bridge.onRunEnd() and step start/end calls automatically. Do not call these yourself — only use text-level bridge methods (e.g. onTextStart, onTextDelta, onTextEnd) or tool-level methods inside the function.

Unit testing entity registration

import { createEntityRegistry } from "@durable-streams/darix-runtime"

const registry = createEntityRegistry()
registerAssistant(registry)

test("registers assistant", () => {
  const entry = registry.get("assistant")
  expect(entry).toBeDefined()
  expect(entry!.definition.handler).toBeTypeOf("function")
})

Unit testing runtime creation

test("creates runtime with types", () => {
  const runtime = createRuntimeHandler({
    baseUrl: "http://localhost:4437",
    serveEndpoint: "http://localhost:3000/webhook",
    registry,
  })
  expect(runtime.typeNames).toContain("assistant")
})

Integration testing

Integration testing with the full DARIX server is possible using the @durable-streams/server-conformance-tests package, which provides test server utilities for running against a live server instance.