Function assistant

packages/opencode/test/acp/usage.test.ts:11–26

(
  input: Partial<UsageService.AssistantMessage> & Pick<UsageService.AssistantMessage, "cost">,
)

import { it } from "../lib/effect"

const assistant = (
  input: Partial<UsageService.AssistantMessage> & Pick<UsageService.AssistantMessage, "cost">,
): UsageService.SessionMessage => ({
  info: {
    role: "assistant",
    providerID: "anthropic",
    modelID: "claude-sonnet",
    tokens: {
      input: 10,
      output: 20,
      reasoning: 0,
      cache: { read: 0, write: 0 },
    },
    ...input,
  },
})

const user = (): UsageService.SessionMessage => ({
  info: { role: "user" },