AGENTS.md 4.4 KB

Test Fixtures Guide

Temporary Directory Fixture

The tmpdir function in fixture/fixture.ts creates temporary directories for tests with automatic cleanup.

Basic Usage

import { tmpdir } from "./fixture/fixture"

test("example", async () => {
  await using tmp = await tmpdir()
  // tmp.path is the temp directory path
  // automatically cleaned up when test ends
})

Options

  • git?: boolean - Initialize a git repo with a root commit
  • config?: Partial<Config.Info> - Write an opencode.json config file
  • init?: (dir: string) => Promise<T> - Custom setup function, returns value accessible as tmp.extra
  • dispose?: (dir: string) => Promise<T> - Custom cleanup function

Examples

Git repository:

await using tmp = await tmpdir({ git: true })

With config file:

await using tmp = await tmpdir({
  config: { model: "test/model", username: "testuser" },
})

Custom initialization (returns extra data):

await using tmp = await tmpdir<string>({
  init: async (dir) => {
    await Bun.write(path.join(dir, "file.txt"), "content")
    return "extra data"
  },
})
// Access extra data via tmp.extra
console.log(tmp.extra) // "extra data"

With cleanup:

await using tmp = await tmpdir({
  init: async (dir) => {
    const specialDir = path.join(dir, "special")
    await fs.mkdir(specialDir)
    return specialDir
  },
  dispose: async (dir) => {
    // Custom cleanup logic
    await fs.rm(path.join(dir, "special"), { recursive: true })
  },
})

Returned Object

  • path: string - Absolute path to the temp directory (realpath resolved)
  • extra: T - Value returned by the init function
  • [Symbol.asyncDispose] - Enables automatic cleanup via await using

Notes

  • Directories are created in the system temp folder with prefix opencode-test-
  • Use await using for automatic cleanup when the variable goes out of scope
  • Paths are sanitized to strip null bytes (defensive fix for CI environments)

Testing With Effects

Use testEffect(...) from test/lib/effect.ts for tests that exercise Effect services or Effect-based workflows.

Core Pattern

import { describe, expect } from "bun:test"
import { Effect, Layer } from "effect"
import { provideTmpdirInstance } from "../fixture/fixture"
import { testEffect } from "../lib/effect"

const it = testEffect(Layer.mergeAll(MyService.defaultLayer))

describe("my service", () => {
  it.live("does the thing", () =>
    provideTmpdirInstance(() =>
      Effect.gen(function* () {
        const svc = yield* MyService.Service
        const out = yield* svc.run()
        expect(out).toEqual("ok")
      }),
    ),
  )
})

it.effect vs it.live

  • Use it.effect(...) when the test should run with TestClock and TestConsole.
  • Use it.live(...) when the test depends on real time, filesystem mtimes, child processes, git, locks, or other live OS behavior.
  • Most integration-style tests in this package use it.live(...).

Effect Fixtures

Prefer the Effect-aware helpers from fixture/fixture.ts instead of building a manual runtime in each test.

  • tmpdirScoped(options?) creates a scoped temp directory and cleans it up when the Effect scope closes.
  • provideInstance(dir)(effect) is the low-level helper. It does not create a directory; it just runs an Effect with Instance.current bound to dir.
  • provideTmpdirInstance((dir) => effect, options?) is the convenience helper. It creates a temp directory, binds it as the active instance, and disposes the instance on cleanup.
  • provideTmpdirServer((input) => effect, options?) does the same, but also provides the test LLM server.

Use provideTmpdirInstance(...) by default when a test only needs one temp instance. Use tmpdirScoped() plus provideInstance(...) when a test needs multiple directories, custom setup before binding, or needs to switch instance context within one test.

Style

  • Define const it = testEffect(...) near the top of the file.
  • Keep the test body inside Effect.gen(function* () { ... }).
  • Yield services directly with yield* MyService.Service or yield* MyTool.
  • Avoid custom ManagedRuntime, attach(...), or ad hoc run(...) wrappers when testEffect(...) already provides the runtime.
  • When a test needs instance-local state, prefer provideTmpdirInstance(...) or provideInstance(...) over manual Instance.provide(...) inside Promise-style tests.