effect-tsでキャッチ系をいろいろ試す

Posted at 2025-11-02

defectの扱いが思ったよりも複雑なため調査する
ソースコードは前回作ったものを利用する

前回

使用する関数一覧

catch
catchAll
catchAllCause
catchAllDefect
catchIf
catchSome
catchSomeCause
catchSomeDefect
catchTag
catchTags

前提となる処理

function routeFareCalculation(input: InputDataType) {
  const [start, end] = input.route
  if (start < 0) {
    const die_result = DieMessage("startの値が不正です")
    return Effect.die(die_result)
  }
  if (end < 0) {
    const die_result = DieMessage("endの値が不正です")
    return Effect.die(die_result)
  }
  if (start === 777) {
    throw 123
  }

  if (start === end) {
    const ng_result = FailMessage("開始位置と終了位置が同じです")
    return Effect.fail(ng_result)
  } else {
    const ok_result = Math.abs(start - end)
    return Effect.succeed(ok_result)
  }
}

const targetTask = () => routeFareCalculation(input)
const tryEffect = Effect.try(targetTask)

変数名	型	備考
targetTask	Effect.Effect<never, FailMessage, never> \| Effect.Effect<number, never, never>	実質的には... : Effect.Effect<number, FailMessage, never>
tryEffect	Effect.Effect<Effect.Effect<never, FailMessage, never> \| Effect.Effect<number, never, never>, Cause.UnknownException, never>	実質的には... : Effect.Effect<targetTaskの型, Cause.UnknownException, never>
defect_result	Effect.Effect<never, FailMessage, never> \| Effect.Effect<number, never, never> \| Cause.Cause<Cause.UnknownException>	実質的には... : targetTaskの型 \| Cause.Cause

tryEffect で Cause.UnknownException が生成されるので、
それをCause.Causeに詰め込むことでエラー処理とする
できるだけ処理が同じようになることを目指す

結果

関数名	引数で渡される型	備考
catch	Cause.UnknownException	Effect.cause
catchAll	E == Cause.UnknownException	Effect.cause(Effect.fail(e))
catchAllCause	Cause.Cause<E> == Cause.Cause<Cause.UnknownException>	Option.some
catchAllDefect	unknown	うまく動作するコードが書けなかった
catchIf	E == Cause.UnknownException	Effect.cause
catchSome	NoInfer<E> == Cause.UnknownException	Option.some(Effect.cause(e))
catchSomeCause	Cause.Cause<NoInfer<E>> == Cause.Cause<Cause.UnknownException>	Option.some(Effect.cause(Effect.failCause(e)))
catchSomeDefect	unknown	うまく動作するコードが書けなかった
catchTag	Extract<NoInfer<E>, { _tag: K[number] }> == Cause.UnknownException	Effect.cause
catchTags	Extract<E, { _tag: K }> == Cause.Cause<unknown>	Effect.cause

処理詳細

エラー時の動作

⭕の場合

defect: UnknownException: An unknown error occurred in Effect.try
...

✖の場合

Process exited with code 1
Uncaught FiberFailureImpl UnknownException: An unknown error occurred in Effect.try
...

OK時の動作

start: 123, end: 456, fare: 333

NG-die時の動作

die: startの値が不正です

NG-fail時の動作

fail: 開始位置と終了位置が同じです

⭕と✖

関数名	エラーの動作	OKの動作	NG-dieの動作	NG-failの動作
catch	⭕	⭕	⭕	⭕
catchAll	⭕	⭕	⭕	⭕
catchAllCause	⭕	⭕	⭕	⭕
catchAllDefect	✖	⭕	⭕	⭕
catchIf	⭕	⭕	⭕	⭕
catchSome	⭕	⭕	⭕	⭕
catchSomeCause	⭕	⭕	⭕	⭕
catchSomeDefect	✖	⭕	⭕	⭕
catchTag	⭕	⭕	⭕	⭕
catchTags	⭕	⭕	⭕	⭕

ソース全部

import { Brand, Cause, Effect, Exit, Option, Schema } from "effect"

const InputData = Schema.Struct({
  route: Schema.Tuple(Schema.Number, Schema.Number)
})
type InputDataType = typeof InputData.Type

// ---- 料金計算 ----
function routeFareCalculation(input: InputDataType) {
  const [start, end] = input.route
  if (start < 0) {
    const die_result = DieMessage("startの値が不正です")
    return Effect.die(die_result)
  }
  if (end < 0) {
    const die_result = DieMessage("endの値が不正です")
    return Effect.die(die_result)
  }
  if (start === 777) {
    throw 123
  }

  if (start === end) {
    const ng_result = FailMessage("開始位置と終了位置が同じです")
    return Effect.fail(ng_result)
  } else {
    const ok_result = Math.abs(start - end)
    return Effect.succeed(ok_result)
  }
}

// ---- OKデータ処理 ----
const RouteAndFareData = Schema.Struct({
  route: Schema.Tuple(Schema.Number, Schema.Number),
  fare: Schema.Number
})
type RouteAndFareDataType = typeof RouteAndFareData.Type

function displayRouteAndFare(routeAndFare: RouteAndFareDataType) {
  const [start, end] = routeAndFare.route
  console.log(`start: ${start}, end: ${end}, fare: ${routeAndFare.fare}`)
}

// ---- NGデータ処理 ----
type FailMessage = string & Brand.Brand<"FailMessage">
const FailMessage = Brand.nominal<FailMessage>()
function displayFail(fail: FailMessage) {
  console.log(`fail: ${fail}`)
}

type DieMessage = string & Brand.Brand<"DieMessage">
const DieMessage = Brand.nominal<DieMessage>()
function displayDie(die: DieMessage | unknown) {
  console.log(`die: ${die}`)
}

function displayDefect(defect: unknown) {
  console.log(`defect: ${defect}`)
}

const program = Effect.gen(function*() {
  // const input = InputData.make({ route: [123, 456] }) // ok
  //   const input = InputData.make({ route: [456, 123] }) // ok
  const input = InputData.make({ route: [111, 111] }) // ng fail
  // const input = InputData.make({ route: [-111, 111] }) // ng die
  // const input = InputData.make({ route: [777, 111] }) // ng throw defect

  const targetTask = () => routeFareCalculation(input)
  const tryEffect = Effect.try(targetTask)

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catch("_tag", {
  //     failure: "UnknownException",
  //     onFailure: Effect.cause
  //   })
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchAll((e) => {
  //     return Effect.cause(Effect.fail(e))
  //   })
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchAllCause(Option.some)
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchAllDefect((e) => {
  //     return Effect.cause(Effect.fail(e))
  //   })
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchIf(
  //     (error) => error._tag === "UnknownException",
  //     Effect.cause
  //   )
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchSome((e) => Option.some(Effect.cause(e)))
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchSomeCause((e) => Option.some(Effect.cause(Effect.failCause(e))))
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchSomeDefect((e) => Option.some(Effect.cause(Effect.fail(e))))
  // )

  // const defect_result = yield* tryEffect.pipe(
  //   Effect.catchTag("UnknownException", Effect.cause)
  // )

  const defect_result = yield* tryEffect.pipe(
    Effect.catchTags({ UnknownException: Effect.cause })
  )

  if (Cause.isCause(defect_result)) {
    displayDefect(defect_result)
  } else {
    const result = yield* Effect.exit(defect_result)

    if (Exit.isSuccess(result)) {
      const ok_result = result.value
      const routeAndFare = RouteAndFareData.make({
        route: input.route,
        fare: ok_result
      })
      displayRouteAndFare(routeAndFare)
    } else {
      Cause.match(result.cause, {
        onFail: (ng_result) => displayFail(ng_result),
        onEmpty: undefined,
        onDie: (die_result) => {
          displayDie(die_result)
        },
        onInterrupt: (_) => {
          throw _
        },
        onSequential: (_) => {
          throw _
        },
        onParallel: (_) => {
          throw _
        }
      })
    }
  }
})

Effect.runSync(program)

You get articles that match your needs
You can efficiently read back useful information
You can use dark theme

What you can do with signing up