refactor(skill): effectify SkillService as scoped service (#17849)

packages/opencode/package.json

@@ -95,6 +95,7 @@
     "@openrouter/ai-sdk-provider": "1.5.4",
     "@opentui/core": "0.1.87",
     "@opentui/solid": "0.1.87",
+    "@effect/platform-node": "4.0.0-beta.31",
     "@parcel/watcher": "2.5.1",
     "@pierre/diffs": "catalog:",
     "@solid-primitives/event-bus": "1.1.2",

packages/opencode/src/effect/instances.ts

@@ -9,6 +9,7 @@ import { VcsService } from "@/project/vcs"
 import { FileTimeService } from "@/file/time"
 import { FormatService } from "@/format"
 import { FileService } from "@/file"
+import { SkillService } from "@/skill/skill"
 import { Instance } from "@/project/instance"
 
 export { InstanceContext } from "./instance-context"
@@ -22,6 +23,7 @@ export type InstanceServices =
   | FileTimeService
   | FormatService
   | FileService
+  | SkillService
 
 function lookup(directory: string) {
   const project = Instance.project
@@ -35,6 +37,7 @@ function lookup(directory: string) {
     Layer.fresh(FileTimeService.layer).pipe(Layer.orDie),
     Layer.fresh(FormatService.layer),
     Layer.fresh(FileService.layer),
+    Layer.fresh(SkillService.layer),
   ).pipe(Layer.provide(ctx))
 }
 

packages/opencode/src/skill/discovery.ts

@@ -1,98 +1,118 @@
-import path from "path"
+import { NodeFileSystem, NodePath } from "@effect/platform-node"
-import { mkdir } from "fs/promises"
+import { Effect, FileSystem, Layer, Path, Schema, ServiceMap } from "effect"
-import { Log } from "../util/log"
+import { FetchHttpClient, HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
 import { Global } from "../global"
-import { Filesystem } from "../util/filesystem"
+import { Log } from "../util/log"
+import { withTransientReadRetry } from "@/util/effect-http-client"
 
-export namespace Discovery {
+class IndexSkill extends Schema.Class<IndexSkill>("IndexSkill")({
-  const log = Log.create({ service: "skill-discovery" })
+  name: Schema.String,
+  files: Schema.Array(Schema.String),
+}) {}
 
-  type Index = {
+class Index extends Schema.Class<Index>("Index")({
-    skills: Array<{
+  skills: Schema.Array(IndexSkill),
-      name: string
+}) {}
-      description: string
-      files: string[]
-    }>
-  }
 
-  export function dir() {
+const skillConcurrency = 4
-    return path.join(Global.Path.cache, "skills")
+const fileConcurrency = 8
-  }
 
-  async function get(url: string, dest: string): Promise<boolean> {
+export namespace DiscoveryService {
-    if (await Filesystem.exists(dest)) return true
+  export interface Service {
-    return fetch(url)
+    readonly pull: (url: string) => Effect.Effect<string[]>
-      .then(async (response) => {
-        if (!response.ok) {
-          log.error("failed to download", { url, status: response.status })
-          return false
-        }
-        if (response.body) await Filesystem.writeStream(dest, response.body)
-        return true
-      })
-      .catch((err) => {
-        log.error("failed to download", { url, err })
-        return false
-      })
-  }
-
-  export async function pull(url: string): Promise<string[]> {
-    const result: string[] = []
-    const base = url.endsWith("/") ? url : `${url}/`
-    const index = new URL("index.json", base).href
-    const cache = dir()
-    const host = base.slice(0, -1)
-
-    log.info("fetching index", { url: index })
-    const data = await fetch(index)
-      .then(async (response) => {
-        if (!response.ok) {
-          log.error("failed to fetch index", { url: index, status: response.status })
-          return undefined
-        }
-        return response
-          .json()
-          .then((json) => json as Index)
-          .catch((err) => {
-            log.error("failed to parse index", { url: index, err })
-            return undefined
-          })
-      })
-      .catch((err) => {
-        log.error("failed to fetch index", { url: index, err })
-        return undefined
-      })
-
-    if (!data?.skills || !Array.isArray(data.skills)) {
-      log.warn("invalid index format", { url: index })
-      return result
-    }
-
-    const list = data.skills.filter((skill) => {
-      if (!skill?.name || !Array.isArray(skill.files)) {
-        log.warn("invalid skill entry", { url: index, skill })
-        return false
-      }
-      return true
-    })
-
-    await Promise.all(
-      list.map(async (skill) => {
-        const root = path.join(cache, skill.name)
-        await Promise.all(
-          skill.files.map(async (file) => {
-            const link = new URL(file, `${host}/${skill.name}/`).href
-            const dest = path.join(root, file)
-            await mkdir(path.dirname(dest), { recursive: true })
-            await get(link, dest)
-          }),
-        )
-
-        const md = path.join(root, "SKILL.md")
-        if (await Filesystem.exists(md)) result.push(root)
-      }),
-    )
-
-    return result
   }
 }
+
+export class DiscoveryService extends ServiceMap.Service<DiscoveryService, DiscoveryService.Service>()(
+  "@opencode/SkillDiscovery",
+) {
+  static readonly layer = Layer.effect(
+    DiscoveryService,
+    Effect.gen(function* () {
+      const log = Log.create({ service: "skill-discovery" })
+      const fs = yield* FileSystem.FileSystem
+      const path = yield* Path.Path
+      const http = HttpClient.filterStatusOk(withTransientReadRetry(yield* HttpClient.HttpClient))
+      const cache = path.join(Global.Path.cache, "skills")
+
+      const download = Effect.fn("DiscoveryService.download")(function* (url: string, dest: string) {
+        if (yield* fs.exists(dest).pipe(Effect.orDie)) return true
+
+        return yield* HttpClientRequest.get(url).pipe(
+          http.execute,
+          Effect.flatMap((res) => res.arrayBuffer),
+          Effect.flatMap((body) =>
+            fs
+              .makeDirectory(path.dirname(dest), { recursive: true })
+              .pipe(Effect.flatMap(() => fs.writeFile(dest, new Uint8Array(body)))),
+          ),
+          Effect.as(true),
+          Effect.catch((err) =>
+            Effect.sync(() => {
+              log.error("failed to download", { url, err })
+              return false
+            }),
+          ),
+        )
+      })
+
+      const pull: DiscoveryService.Service["pull"] = Effect.fn("DiscoveryService.pull")(function* (url: string) {
+        const base = url.endsWith("/") ? url : `${url}/`
+        const index = new URL("index.json", base).href
+        const host = base.slice(0, -1)
+
+        log.info("fetching index", { url: index })
+
+        const data = yield* HttpClientRequest.get(index).pipe(
+          HttpClientRequest.acceptJson,
+          http.execute,
+          Effect.flatMap(HttpClientResponse.schemaBodyJson(Index)),
+          Effect.catch((err) =>
+            Effect.sync(() => {
+              log.error("failed to fetch index", { url: index, err })
+              return null
+            }),
+          ),
+        )
+
+        if (!data) return []
+
+        const list = data.skills.filter((skill) => {
+          if (!skill.files.includes("SKILL.md")) {
+            log.warn("skill entry missing SKILL.md", { url: index, skill: skill.name })
+            return false
+          }
+          return true
+        })
+
+        const dirs = yield* Effect.forEach(
+          list,
+          (skill) =>
+            Effect.gen(function* () {
+              const root = path.join(cache, skill.name)
+
+              yield* Effect.forEach(
+                skill.files,
+                (file) => download(new URL(file, `${host}/${skill.name}/`).href, path.join(root, file)),
+                { concurrency: fileConcurrency },
+              )
+
+              const md = path.join(root, "SKILL.md")
+              return (yield* fs.exists(md).pipe(Effect.orDie)) ? root : null
+            }),
+          { concurrency: skillConcurrency },
+        )
+
+        return dirs.filter((dir): dir is string => dir !== null)
+      })
+
+      return DiscoveryService.of({ pull })
+    }),
+  )
+
+  static readonly defaultLayer = DiscoveryService.layer.pipe(
+    Layer.provide(FetchHttpClient.layer),
+    Layer.provide(NodeFileSystem.layer),
+    Layer.provide(NodePath.layer),
+  )
+}

packages/opencode/src/skill/skill.ts

@@ -10,15 +10,25 @@ import { Global } from "@/global"
 import { Filesystem } from "@/util/filesystem"
 import { Flag } from "@/flag/flag"
 import { Bus } from "@/bus"
-import { Session } from "@/session"
+import { DiscoveryService } from "./discovery"
-import { Discovery } from "./discovery"
 import { Glob } from "../util/glob"
 import { pathToFileURL } from "url"
 import type { Agent } from "@/agent/agent"
 import { PermissionNext } from "@/permission/next"
+import { InstanceContext } from "@/effect/instance-context"
+import { Effect, Layer, ServiceMap } from "effect"
+import { runPromiseInstance } from "@/effect/runtime"
+
+const log = Log.create({ service: "skill" })
+
+// External skill directories to search for (project-level and global)
+// These follow the directory layout used by Claude Code and other agents.
+const EXTERNAL_DIRS = [".claude", ".agents"]
+const EXTERNAL_SKILL_PATTERN = "skills/**/SKILL.md"
+const OPENCODE_SKILL_PATTERN = "{skill,skills}/**/SKILL.md"
+const SKILL_PATTERN = "**/SKILL.md"
 
 export namespace Skill {
-  const log = Log.create({ service: "skill" })
   export const Info = z.object({
     name: z.string(),
     description: z.string(),
@@ -45,155 +55,20 @@ export namespace Skill {
     }),
   )
 
-  // External skill directories to search for (project-level and global)
-  // These follow the directory layout used by Claude Code and other agents.
-  const EXTERNAL_DIRS = [".claude", ".agents"]
-  const EXTERNAL_SKILL_PATTERN = "skills/**/SKILL.md"
-  const OPENCODE_SKILL_PATTERN = "{skill,skills}/**/SKILL.md"
-  const SKILL_PATTERN = "**/SKILL.md"
-
-  export const state = Instance.state(async () => {
-    const skills: Record<string, Info> = {}
-    const dirs = new Set<string>()
-
-    const addSkill = async (match: string) => {
-      const md = await ConfigMarkdown.parse(match).catch((err) => {
-        const message = ConfigMarkdown.FrontmatterError.isInstance(err)
-          ? err.data.message
-          : `Failed to parse skill ${match}`
-        Bus.publish(Session.Event.Error, { error: new NamedError.Unknown({ message }).toObject() })
-        log.error("failed to load skill", { skill: match, err })
-        return undefined
-      })
-
-      if (!md) return
-
-      const parsed = Info.pick({ name: true, description: true }).safeParse(md.data)
-      if (!parsed.success) return
-
-      // Warn on duplicate skill names
-      if (skills[parsed.data.name]) {
-        log.warn("duplicate skill name", {
-          name: parsed.data.name,
-          existing: skills[parsed.data.name].location,
-          duplicate: match,
-        })
-      }
-
-      dirs.add(path.dirname(match))
-
-      skills[parsed.data.name] = {
-        name: parsed.data.name,
-        description: parsed.data.description,
-        location: match,
-        content: md.content,
-      }
-    }
-
-    const scanExternal = async (root: string, scope: "global" | "project") => {
-      return Glob.scan(EXTERNAL_SKILL_PATTERN, {
-        cwd: root,
-        absolute: true,
-        include: "file",
-        dot: true,
-        symlink: true,
-      })
-        .then((matches) => Promise.all(matches.map(addSkill)))
-        .catch((error) => {
-          log.error(`failed to scan ${scope} skills`, { dir: root, error })
-        })
-    }
-
-    // Scan external skill directories (.claude/skills/, .agents/skills/, etc.)
-    // Load global (home) first, then project-level (so project-level overwrites)
-    if (!Flag.OPENCODE_DISABLE_EXTERNAL_SKILLS) {
-      for (const dir of EXTERNAL_DIRS) {
-        const root = path.join(Global.Path.home, dir)
-        if (!(await Filesystem.isDir(root))) continue
-        await scanExternal(root, "global")
-      }
-
-      for await (const root of Filesystem.up({
-        targets: EXTERNAL_DIRS,
-        start: Instance.directory,
-        stop: Instance.worktree,
-      })) {
-        await scanExternal(root, "project")
-      }
-    }
-
-    // Scan .opencode/skill/ directories
-    for (const dir of await Config.directories()) {
-      const matches = await Glob.scan(OPENCODE_SKILL_PATTERN, {
-        cwd: dir,
-        absolute: true,
-        include: "file",
-        symlink: true,
-      })
-      for (const match of matches) {
-        await addSkill(match)
-      }
-    }
-
-    // Scan additional skill paths from config
-    const config = await Config.get()
-    for (const skillPath of config.skills?.paths ?? []) {
-      const expanded = skillPath.startsWith("~/") ? path.join(os.homedir(), skillPath.slice(2)) : skillPath
-      const resolved = path.isAbsolute(expanded) ? expanded : path.join(Instance.directory, expanded)
-      if (!(await Filesystem.isDir(resolved))) {
-        log.warn("skill path not found", { path: resolved })
-        continue
-      }
-      const matches = await Glob.scan(SKILL_PATTERN, {
-        cwd: resolved,
-        absolute: true,
-        include: "file",
-        symlink: true,
-      })
-      for (const match of matches) {
-        await addSkill(match)
-      }
-    }
-
-    // Download and load skills from URLs
-    for (const url of config.skills?.urls ?? []) {
-      const list = await Discovery.pull(url)
-      for (const dir of list) {
-        dirs.add(dir)
-        const matches = await Glob.scan(SKILL_PATTERN, {
-          cwd: dir,
-          absolute: true,
-          include: "file",
-          symlink: true,
-        })
-        for (const match of matches) {
-          await addSkill(match)
-        }
-      }
-    }
-
-    return {
-      skills,
-      dirs: Array.from(dirs),
-    }
-  })
-
   export async function get(name: string) {
-    return state().then((x) => x.skills[name])
+    return runPromiseInstance(SkillService.use((s) => s.get(name)))
   }
 
   export async function all() {
-    return state().then((x) => Object.values(x.skills))
+    return runPromiseInstance(SkillService.use((s) => s.all()))
   }
 
   export async function dirs() {
-    return state().then((x) => x.dirs)
+    return runPromiseInstance(SkillService.use((s) => s.dirs()))
   }
 
   export async function available(agent?: Agent.Info) {
-    const list = await all()
+    return runPromiseInstance(SkillService.use((s) => s.available(agent)))
-    if (!agent) return list
-    return list.filter((skill) => PermissionNext.evaluate("skill", skill.name, agent.permission).action !== "deny")
   }
 
   export function fmt(list: Info[], opts: { verbose: boolean }) {
@@ -216,3 +91,177 @@ export namespace Skill {
     return ["## Available Skills", ...list.flatMap((skill) => `- **${skill.name}**: ${skill.description}`)].join("\n")
   }
 }
+
+export namespace SkillService {
+  export interface Service {
+    readonly get: (name: string) => Effect.Effect<Skill.Info | undefined>
+    readonly all: () => Effect.Effect<Skill.Info[]>
+    readonly dirs: () => Effect.Effect<string[]>
+    readonly available: (agent?: Agent.Info) => Effect.Effect<Skill.Info[]>
+  }
+}
+
+export class SkillService extends ServiceMap.Service<SkillService, SkillService.Service>()("@opencode/Skill") {
+  static readonly layer = Layer.effect(
+    SkillService,
+    Effect.gen(function* () {
+      const instance = yield* InstanceContext
+      const discovery = yield* DiscoveryService
+
+      const skills: Record<string, Skill.Info> = {}
+      const skillDirs = new Set<string>()
+      let task: Promise<void> | undefined
+
+      const addSkill = async (match: string) => {
+        const md = await ConfigMarkdown.parse(match).catch(async (err) => {
+          const message = ConfigMarkdown.FrontmatterError.isInstance(err)
+            ? err.data.message
+            : `Failed to parse skill ${match}`
+          const { Session } = await import("@/session")
+          Bus.publish(Session.Event.Error, { error: new NamedError.Unknown({ message }).toObject() })
+          log.error("failed to load skill", { skill: match, err })
+          return undefined
+        })
+
+        if (!md) return
+
+        const parsed = Skill.Info.pick({ name: true, description: true }).safeParse(md.data)
+        if (!parsed.success) return
+
+        // Warn on duplicate skill names
+        if (skills[parsed.data.name]) {
+          log.warn("duplicate skill name", {
+            name: parsed.data.name,
+            existing: skills[parsed.data.name].location,
+            duplicate: match,
+          })
+        }
+
+        skillDirs.add(path.dirname(match))
+
+        skills[parsed.data.name] = {
+          name: parsed.data.name,
+          description: parsed.data.description,
+          location: match,
+          content: md.content,
+        }
+      }
+
+      const scanExternal = async (root: string, scope: "global" | "project") => {
+        return Glob.scan(EXTERNAL_SKILL_PATTERN, {
+          cwd: root,
+          absolute: true,
+          include: "file",
+          dot: true,
+          symlink: true,
+        })
+          .then((matches) => Promise.all(matches.map(addSkill)))
+          .catch((error) => {
+            log.error(`failed to scan ${scope} skills`, { dir: root, error })
+          })
+      }
+
+      function ensureScanned() {
+        if (task) return task
+        task = (async () => {
+          // Scan external skill directories (.claude/skills/, .agents/skills/, etc.)
+          // Load global (home) first, then project-level (so project-level overwrites)
+          if (!Flag.OPENCODE_DISABLE_EXTERNAL_SKILLS) {
+            for (const dir of EXTERNAL_DIRS) {
+              const root = path.join(Global.Path.home, dir)
+              if (!(await Filesystem.isDir(root))) continue
+              await scanExternal(root, "global")
+            }
+
+            for await (const root of Filesystem.up({
+              targets: EXTERNAL_DIRS,
+              start: instance.directory,
+              stop: instance.project.worktree,
+            })) {
+              await scanExternal(root, "project")
+            }
+          }
+
+          // Scan .opencode/skill/ directories
+          for (const dir of await Config.directories()) {
+            const matches = await Glob.scan(OPENCODE_SKILL_PATTERN, {
+              cwd: dir,
+              absolute: true,
+              include: "file",
+              symlink: true,
+            })
+            for (const match of matches) {
+              await addSkill(match)
+            }
+          }
+
+          // Scan additional skill paths from config
+          const config = await Config.get()
+          for (const skillPath of config.skills?.paths ?? []) {
+            const expanded = skillPath.startsWith("~/") ? path.join(os.homedir(), skillPath.slice(2)) : skillPath
+            const resolved = path.isAbsolute(expanded) ? expanded : path.join(instance.directory, expanded)
+            if (!(await Filesystem.isDir(resolved))) {
+              log.warn("skill path not found", { path: resolved })
+              continue
+            }
+            const matches = await Glob.scan(SKILL_PATTERN, {
+              cwd: resolved,
+              absolute: true,
+              include: "file",
+              symlink: true,
+            })
+            for (const match of matches) {
+              await addSkill(match)
+            }
+          }
+
+          // Download and load skills from URLs
+          for (const url of config.skills?.urls ?? []) {
+            const list = await Effect.runPromise(discovery.pull(url))
+            for (const dir of list) {
+              skillDirs.add(dir)
+              const matches = await Glob.scan(SKILL_PATTERN, {
+                cwd: dir,
+                absolute: true,
+                include: "file",
+                symlink: true,
+              })
+              for (const match of matches) {
+                await addSkill(match)
+              }
+            }
+          }
+
+          log.info("init", { count: Object.keys(skills).length })
+        })().catch((err) => {
+          task = undefined
+          throw err
+        })
+        return task
+      }
+
+      return SkillService.of({
+        get: Effect.fn("SkillService.get")(function* (name: string) {
+          yield* Effect.promise(() => ensureScanned())
+          return skills[name]
+        }),
+        all: Effect.fn("SkillService.all")(function* () {
+          yield* Effect.promise(() => ensureScanned())
+          return Object.values(skills)
+        }),
+        dirs: Effect.fn("SkillService.dirs")(function* () {
+          yield* Effect.promise(() => ensureScanned())
+          return Array.from(skillDirs)
+        }),
+        available: Effect.fn("SkillService.available")(function* (agent?: Agent.Info) {
+          yield* Effect.promise(() => ensureScanned())
+          const list = Object.values(skills)
+          if (!agent) return list
+          return list.filter(
+            (skill) => PermissionNext.evaluate("skill", skill.name, agent.permission).action !== "deny",
+          )
+        }),
+      })
+    }),
+  ).pipe(Layer.provide(DiscoveryService.defaultLayer))
+}

packages/opencode/test/skill/discovery.test.ts

@@ -1,5 +1,7 @@
 import { describe, test, expect, beforeAll, afterAll } from "bun:test"
-import { Discovery } from "../../src/skill/discovery"
+import { Effect } from "effect"
+import { DiscoveryService } from "../../src/skill/discovery"
+import { Global } from "../../src/global"
 import { Filesystem } from "../../src/util/filesystem"
 import { rm } from "fs/promises"
 import path from "path"
@@ -9,9 +11,10 @@ let server: ReturnType<typeof Bun.serve>
 let downloadCount = 0
 
 const fixturePath = path.join(import.meta.dir, "../fixture/skills")
+const cacheDir = path.join(Global.Path.cache, "skills")
 
 beforeAll(async () => {
-  await rm(Discovery.dir(), { recursive: true, force: true })
+  await rm(cacheDir, { recursive: true, force: true })
 
   server = Bun.serve({
     port: 0,
@@ -40,22 +43,25 @@ beforeAll(async () => {
 
 afterAll(async () => {
   server?.stop()
-  await rm(Discovery.dir(), { recursive: true, force: true })
+  await rm(cacheDir, { recursive: true, force: true })
 })
 
 describe("Discovery.pull", () => {
+  const pull = (url: string) =>
+    Effect.runPromise(DiscoveryService.use((s) => s.pull(url)).pipe(Effect.provide(DiscoveryService.defaultLayer)))
+
   test("downloads skills from cloudflare url", async () => {
-    const dirs = await Discovery.pull(CLOUDFLARE_SKILLS_URL)
+    const dirs = await pull(CLOUDFLARE_SKILLS_URL)
     expect(dirs.length).toBeGreaterThan(0)
     for (const dir of dirs) {
-      expect(dir).toStartWith(Discovery.dir())
+      expect(dir).toStartWith(cacheDir)
       const md = path.join(dir, "SKILL.md")
       expect(await Filesystem.exists(md)).toBe(true)
     }
   })
 
   test("url without trailing slash works", async () => {
-    const dirs = await Discovery.pull(CLOUDFLARE_SKILLS_URL.replace(/\/$/, ""))
+    const dirs = await pull(CLOUDFLARE_SKILLS_URL.replace(/\/$/, ""))
     expect(dirs.length).toBeGreaterThan(0)
     for (const dir of dirs) {
       const md = path.join(dir, "SKILL.md")
@@ -64,18 +70,18 @@ describe("Discovery.pull", () => {
   })
 
   test("returns empty array for invalid url", async () => {
-    const dirs = await Discovery.pull(`http://localhost:${server.port}/invalid-url/`)
+    const dirs = await pull(`http://localhost:${server.port}/invalid-url/`)
     expect(dirs).toEqual([])
   })
 
   test("returns empty array for non-json response", async () => {
     // any url not explicitly handled in server returns 404 text "Not Found"
-    const dirs = await Discovery.pull(`http://localhost:${server.port}/some-other-path/`)
+    const dirs = await pull(`http://localhost:${server.port}/some-other-path/`)
     expect(dirs).toEqual([])
   })
 
   test("downloads reference files alongside SKILL.md", async () => {
-    const dirs = await Discovery.pull(CLOUDFLARE_SKILLS_URL)
+    const dirs = await pull(CLOUDFLARE_SKILLS_URL)
     // find a skill dir that should have reference files (e.g. agents-sdk)
     const agentsSdk = dirs.find((d) => d.endsWith(path.sep + "agents-sdk"))
     expect(agentsSdk).toBeDefined()
@@ -90,17 +96,17 @@ describe("Discovery.pull", () => {
 
   test("caches downloaded files on second pull", async () => {
     // clear dir and downloadCount
-    await rm(Discovery.dir(), { recursive: true, force: true })
+    await rm(cacheDir, { recursive: true, force: true })
     downloadCount = 0
 
     // first pull to populate cache
-    const first = await Discovery.pull(CLOUDFLARE_SKILLS_URL)
+    const first = await pull(CLOUDFLARE_SKILLS_URL)
     expect(first.length).toBeGreaterThan(0)
     const firstCount = downloadCount
     expect(firstCount).toBeGreaterThan(0)
 
     // second pull should return same results from cache
-    const second = await Discovery.pull(CLOUDFLARE_SKILLS_URL)
+    const second = await pull(CLOUDFLARE_SKILLS_URL)
     expect(second.length).toBe(first.length)
     expect(second.sort()).toEqual(first.sort())