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フロントエンドのパラダイムを参考にバックエンド開発を再考する / TypeScript による GraphQL バックエンド開発
2022年10月1日に開催された #postdev での発表です
Naoya Ito
October 01, 2022
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64 slides
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ํͷٕज़తؔ৺ࣄʹΪϟοϓ • ΞϓϦέʔγϣϯͷঢ়ଶཧϞσϧ • σβΠϯγεςϜ • ϓϦϨϯμϦϯά • ŋŋŋ ϑϩϯτΤϯυ
όοΫΤϯυ • υϝΠϯϞσϧ • ϨΠϠʔυɾΞʔΩςΫνϟ • $234 • ŋŋŋ ৫ͷٕज़࿅্͕͕Ε্͕Δ΄Ͳɺؔ৺ࣄͷΪϟοϓ͕͕͍ͬͯͬͨ -
͖͔͚ͬ • ৽نϓϩδΣΫτ্ཱ͕͕ͪΔ • ϑϩϯτΤϯυ 3FBDU3FMBZ3FDPJM Λ࠾༻ • (SBQI2-όοΫΤϯυ ŋŋŋ
Β͘ 1ZUIPOͰɺΫϥεΛଟ༻ͨ͠ΫϦʔϯΞʔΩςΫνϟ తͳઃܭͰ͖͕ͬͯͨɺࠓճͲ͏͢Δ͔ -
৽نϓϩμΫτখ͞ͳνʔϜͰີߴٞͯ͘͠࡞Γ͍ͨ • ސ٬ͷͲΜͳΛɺͲ͏ղܾ͍͔ͨ͠ ŋŋŋ σΟεΧογϣϯΛେࣄʹ͍ͨ͠ – ϑϩϯΤϯυɺόοΫΤϯυؔͳ͘ରυϝΠϯྖҬʹৄ͘͠ͳΓ͍ͨ – ͲΜͳମݧΛɺͲΜͳ 6*ͰɺͲ͏͍͏ϞσϧͰɺͲΜͳσʔλઃܭΛ࣮ͯ͠ݱ͢Δͷ͔ɻॳظ
ϑΣʔζͰશһ͕ͳΔ͓͖͍ͬͯͨ͘͘ • ૣظʹׂΛߦ͍͗͢Δͱɺؔ৺ࣄͷஅΛ༠ൃͯ͠͠·͏ -
3FBDUͰϑϩϯτΤϯυΛ։ൃ͔ͯ͠Βɺ όοΫΤϯυΛॻ͘ͱŋŋŋ • 3FBDUŋŋŋ খ͞ͳؔΛΈ߹Θͤͯએݴతʹॻ͍͍ͯ͘ • όοΫΤϯυ ŋŋŋ ΫϥεΛͨ͘͞Μॻ͍ͯɺϨΠϠʔΛލ͙ͱ %50Ͱͷ٧Ίସ͑Λߦͬ
ͯɺJOUFSGBDFͰґଘੑͷٯసΛߦͬͯŋŋŋ – ʮŋŋŋϑϩϯτΤϯυͩͱ͜͏͍͏͜ͱɺ͋Μ·ΓΒͳ͍ΑͶʯ ։ൃ࣌ͷϝϯλϧϞσϧͷΪϟοϓ͕େ͖͍ ίϯςΩετεΠονͷෛ୲େ͖͍ -
update : Msg -> Model -> ( Model, Cmd Msg
) update msg model = case msg of ToggleLike -> ( { model | photo = Maybe.map toggleLike model.photo }, Cmd.none ) UpdateComment comment -> ( { model | photo = Maybe.map (updateComment comment) model.photo }, Cmd.none ) SaveComment -> ( { model | photo = Maybe.map saveNewComment model.photo }, Cmd.none ) LoadFeed (Ok photo) -> ( { model | photo = Just photo }, Cmd.none ) LoadFeed (Err _) -> ( model, Cmd.none ) viewLikeButton : Photo -> Html Msg viewLikeButton model = let buttonClass = if model.liked then ... div [ class "like-button" ] [ i [ class "fa fa-2x", class buttonClass, onClick ToggleLike ] [] ] &MN 7JFX .PEFMΛඳըɻ Ϣʔβʔૢ࡞ʹԠͯ͡Πϕ ϯτΛૹΔͱŋŋŋ &MNϥϯλΠϜ͕ VQEBUFؔ ΛݺͿɻؔʹΠϕϯτͷछ ྨʹԠͨ͡Ϟσϧͷঢ়ଶભҠΛ هड़͓ͯ͘͠ -
3FDPJM function TextInput() { const [text, setText] = useRecoilState(textState); const
onChange = (event) => { setText(event.target.value); }; return ( <div> <input type="text" value={text} onChange={onChange} /> <br /> Echo: {text} </div> ); } -
ͨͱ͑ʮ॓ധ༧ʯΛྫʹυϝΠϯϞσϧΛվΊͯߟ͑ͯΈΔ • ͲΜͳ؍ʹͯ͠ߟ͑ͯΈΔ͖͔ – σʔλߏ – &3ਤ – Ϋϥεͷ࣮ –
ը໘ • ͍ͣΕ੩తͳߏʹযΛ͍ͯͯΔɻࢹΛม͑ͯΈ͍ͨ – ಈతͳͷŋŋŋυϝΠϯΠϕϯτঢ়ଶʹযΛͯͯΈΔͱ -
ঢ়ଶԿ͔͠ΒͷΠϕϯτΛܖػʹભҠ͢Δ ༧ྃ Ωϟϯηϧ ॓ധࡁΈ ೖྗ ݕূࡁΈ ೖྗະݕূ ࡏݿ֬อ ࡁΈ ༧Λ։࢝ͨ͠
ݕূ͕ྃͨ͠ ࡏݿΛ֬อͨ͠ ༧Λߦͬͨ Ωϟϯηϧ͞Εͨ ॓ധͨ͠ -
model -> model model -> model event &WFOU)BOEMFS 8FC"QQͳΒ SPVUFS
%#ʹอଘ͠ Ϩεϙϯε 6* event event ֎ͷੈք ֎ͷੈք ֎ͷੈք Πϕϯτ ˠϞσϧͷঢ়ଶભҠ 🤔 Ͳ͔͜Ͱݟͨͳŋŋŋ -
ϑϩϯτΤϯυͱόοΫΤϯυͷঢ়ଶཧ • ϑϩϯτΤϯυͷঢ়ଶཧ ŋŋŋ ओͳؔ৺ࣄʮΞϓϦέʔγϣϯͷঢ়ଶʯ • όοΫΤϯυͷঢ়ଶཧ ŋŋŋ ओͳؔ৺ࣄʮυϝΠϯϞσϧɺυϝΠϯΦϒδΣΫτͷঢ় ଶʯ
ཧ͍ͯ͠Δঢ়ଶͷίϯςΩετҧ͏ͷͷ ঢ়ଶཧͷϞσϧࣅͨΑ͏ʹߟ͑ΒΕΔͷͰͳ͍͔ -
͜ͷελΠϧͰΑ͘͏ͷ • type / interface • λά͖ϢχΦϯ ܕ • 3FTVMUܕ
• ΧϦʔԽ • ܕͷϒϥϯυԽ ίϯύχΦϯΦϒδΣΫτ -
5BHΤϯςΟςΟ ूϧʔτ ͷঢ়ଶભҠʹண͢Δ 7BMJEBUFE 6OWBMJEBUFE $SFBUFE ೖྗ͕͋ͬͨ ݕূͨ͠ ࡞ͨ͠ ˞͜͜Ͱͷʮ$SFBUFEʯ͋͘·ͰυϝΠϯΦϒδΣΫτ͕
l࡞ࡁΈzʹͳͬͨঢ়ଶͰ͋ͬͯɺσʔλϕʔεʹϨίʔυ ΛՃͨ͠ɺͱ͍͏ঢ়ଶͰͳ͍ -
5BHΫϥεΛ࡞Δ export class Tag { state: 'Unvalidated' | 'Validated' |
'Created', id: TagId | undefined, groupId: RestaurantGroupId, label: string, icon: TagIcon | undefined, sortOrder: number | undefined, builtin: boolean | undefined } -
export class Tag { state: 'Unvalidated' | 'Validated' | 'Created',
id: TagId | undefined, groupId: RestaurantGroupId, label: string, icon: TagIcon | undefined, sortOrder: number | undefined, builtin: boolean | undefined } ঢ়ଶભҠલʹ֬ఆ͠ͳ͍ϓϩύςΟ͕ VOEFGJOFE ʹͳͬͯ͠·͏ŋŋŋ -
interface UnvalidatedTag { kind: 'Unvalidated' groupId: string label: string icon?:
{ symbol: string; type: TagIconType; color?: string | null | undefined } | null | undefined } interface ValidatedTag { kind: 'Validated' groupId: RestaurantGroupId label: string icon: TagIcon } export interface CreatedTag { kind: 'Created' id: TagId groupId: RestaurantGroupId label: TagLabel icon: TagIcon sortOrder: number builtin: boolean } //※この型は実際には出番がないので使っていない export type Tag = UnvalidatedTag | ValidatedTag | CreatedTag ͦ͜Ͱঢ়ଶ͝ͱʹܕΛఆٛ͢Δ ঢ়ଶ͕ભҠ͢Δ υϝΠϯΠϕ ϯτ͕ൃੜ͢Δ͝ͱʹϞσϧͷ ͕֬ఆ͍ͯ͘͠ͷ͕એݴͰ͖͍ͯ Δ -
l.BLF*MMFHBM4UBUFT6OSFQSFTFOUBCMFz interface User { memberId: MemberId | undefined guestId: GuestId
| undefined } interface Member { userId: MemberId } interface Guest { guestId: GuestId } type User = Member | Guest औΓಘΔͷछྨ֤ଐੑͷੵʹͳΔ ੵ Y ɾ྆ํ VOEFGJOFE ɾ྆ํͷ͕ຒ·Δ ͱ͍͏্༷͋Γಘͳ͍ঢ়ଶ͕ੜ·ΕΔ औΓಘΔछྨ֤ଐੑͷ ্༷͋Γಘͳ͍ঢ়ଶදݱ͠ͳ͍ Ϩίʔυʮ͔ͭ "/% ʯ ϢχΦϯʮ·ͨ 03 ʯ -
ͪ͜ΒΑΓŋŋŋ export class Tag { state: 'Unvalidated' | 'Validated' |
'Created', id: TagId | undefined, groupId: RestaurantGroupId, label: string, icon: TagIcon | undefined, sortOrder: number | undefined, builtin: boolean | undefined } -
interface UnvalidatedTag { kind: 'Unvalidated' groupId: string label: string icon?:
{ symbol: string; type: TagIconType; color?: string | null | undefined } | null | undefined } interface ValidatedTag { kind: 'Validated' groupId: RestaurantGroupId label: string icon: TagIcon } export interface CreatedTag { kind: 'Created' id: TagId groupId: RestaurantGroupId label: TagLabel icon: TagIcon sortOrder: number builtin: boolean } export type Tag = UnvalidatedTag | ValidatedTag | CreatedTag ͪ͜Βͷํ͕ɺͷΈ߹Θͤύλʔϯ͕গͳ͘ݫີ -
type validateTag = (model: UnvalidatedTag) => ValidatedTag const validateTag: validateTag
= (model) => { // (省略: 値の validation ...) return { ...model, kind: 'Validated', groupId: RestaurantGroupId(model.groupId), icon: model.icon ? TagIcon(model.icon) : NoIcon(), } } ঢ়ଶΛભҠͤ͞Δεςοϓ ؔ -
ঢ়ଶΛભҠͤ͞Δεςοϓ ؔ type createTag = (model: ValidatedTag) => CreatedTag
const createTag: CreatedTag = (model) => { return { ...model, kind: 'Created', id: generateTagId(), sortOrder: getTagSortOrder({ groupId: model.groupId }), builtin: false, } } ४උ͕ͬͯॳΊ͕ͯ֬ఆ ͢ΔͷΛࣗવʹهड़Ͱ͖Δ ͳ͓ getTagSortOrder *0͕͋Δ ͨΊ %*͍ͯ͠ΔɻࠓճׂѪ -
ݸผʹఆٛͨ͠ঢ়ଶભҠͷؔΛܨ͍͛ͨ • Ͱɺܭࢉʮ్தͰࣦഊ͢ΔʯՄೳੑ͕͋Δ – ͨͱ͑υϝΠϯϞσϧͷࣄલ݅Λຬͨ͞ͳ͍Τϥʔ – 7BMJEBUJPO&SSPSŋŋŋ – .BY5BH-JNJU&YDFFEFEʜ •
ʮ్தͰࣦഊ͢Δʯ͜ͱΛܕͰએݴͰ͖ͳ͍͔ ˠ 3FTVMUܕ -
3FTVMUܕͰࣦഊͷՄೳੑͷ͋ΔܭࢉΛҰຊಓʹ߹͢Δ import { Result, ok, err } from 'neverthrow' function
itsUnder100(n: number): Result<number, Error> { return n <= 100 ? ok(n) : err(new Error('100より大きい数字です')) } function itsEven(n: number): Result<number, Error> { return n % 2 == 0 ? ok(n) : err(new Error('奇数です')) } function itsPositive(n: number): Result<number, Error> { return n > 0 ? ok(n) : err(new Error('負数です')) } const result = ok(96).andThen(itsUnder100).andThen(itsEven).andThen(itsPositive) result.match( (n) => console.log(n), (error) => { throw error } ) -
type validateTag = (model: UnvalidatedTag) => Result<ValidatedTag, ValidationError> const validateTag:
validateTag = (model) => { const groupId = RestaurantGroupId(model.groupId) const label = TagLabel(model.label) const icon = model.icon ? TagIcon(model.icon) : ok(NoIcon()) const values = Result.combine(tuple(groupId, label, icon)) return values.map(([groupId, label, icon]) => ({ ...model, kind: 'Validated', groupId, label, icon, })) } ঢ়ଶભҠͷޭ ࣦഊΛ 3FTVMUܕͰฦ͢Α͏ʹ͢Δ ͷੜʹࣦഊ͢ΔՄೳੑ͕͋ΔͷͰɺ ͜ΕΒ 3FTVMUܕΛฦ͢ -
3FTVMUܕͰঢ়ଶભҠؔΛܨ͛ͯɺϫʔΫϑϩʔ υϝΠϯϩδοΫ Λ࡞Δ type WorkFlow = (model: UnvalidatedTag) => Result<CreatedTag,
CreateTagError> export const createTagWorkFlow: WorkFlow = (model) => ok(model).andThen(validateTag).andThen(createTag) -
ϫʔΫϑϩʔͷ࢝·ΓͱऴΘΓ͕ɺ֎քͱͷ JOPVU 7BMJEBUFE5BH $SFBUFE5BH 6OWBMJEBUFE5BH 7BMJEBUFE5BH 8PSL'MPX ೖྗͷ%50
ྫ(SBQI2-*OQVU5ZQF Λ 6OWBMJEBUFE5BHʹม UBH3FQPTJUPSZͰ $SFBUFE5BHΛอଘ -
(SBQI2-SFTPMWFS3FQPTJUPSZ %# ͱϫʔΫϑϩʔΛଓ͢Δ import { saveCreatedTag } from '../../../customers/repos/tagRepository' export
const createTagMutation = mutationField('createTag', { ... resolve(_root, { input }, context) { const workflow = createTagWorkFlow() // GraphQL 入力をワークフローの入力に変換 const unvalidatedTag = toUnvalidatedTag({ ...input, groupId: context.operator.groupId, }) // ワークフローを実行し Repository パターンの関数で DB に保存 (ここも Result で繋ぐ) const result = ok(unvalidatedTag).andThen(workflow).andThen(saveCreatedTag(context)) return result.match( (tag) => ({ tag: { ...tag, id: toGlobalId('Tag', tag.id), }, }), (error) => { // ここで初めて例外をスロー (単に Nexus にエラーを伝える手段としてスローする) throw error } ) }, }) -
σʔλϑϩʔϓϩάϥϛϯά • 3FTVMUܕͰࣦഊͷ͋ΔܭࢉΛ߹͠ɺσʔλͷ௨Γಓͱͯ͠ͷܭࢉաఔΛ࡞Δ – ͦ͜ʹσʔλΛ์ΓࠐΉͱɺͦͷதΛ௨ͬͯঢ়ଶભҠͨ͠σʔλ͕ಘΒΕΔ – σʔλΛσʔλͷ··ɺͦͷՄൖੑΛԼ͛ͣʹѻ͍͍ͨɻ݁Ռ class ͷొػձ͕ͳ͍ •
ܭࢉΛҰຊಓʹ͢Δ – େҬग़͠ͳ͍ɻେҬग़͢Δͱܭࢉ͕ҰຊಓʹͳΒͳ͍ ˠྫ֎ΛΘͳ͍ – ࣦഊͷذ 3FTVMUͰ߹ ˞3FTVMUܕϞφυ – ܭࢉ͕ҰຊಓʹͳΔ σʔλෆมɻೝෛՙ͕͘ͳΔ -
ϑϩϯτΤϯυͱͷൺֱ • ࣌ܥྻʹجͮ͘ঢ়ଶભҠ σʔλϑϩʔ Λએݴతʹهड़͢Δɺͱ͍͏ߟ͑ํಉ͡ʹͳͬͨ – ܕͱখ͞ͳؔͷએݴతͳهड़ͰɺϑϩʔΛΈ্͛Δ • ҰํɺϫʔΫϑϩʔͷ࣮Λ͍ͯ͠Δͱ͖ͷײ֮ʹ·ͩڑ͕͋Δ –
υϝΠϯΠϕϯτͰঢ়ଶભҠɺͱ͍ͬͯଟ͘ͷ߹ʮ7BMJEBUFͯ͠ɺೖྗͰυϝΠϯϞσϧ Λߋ৽͢Δʯ͚ͩ • ݁ՌɺϫʔΫϑϩʔఆܕతͳهड़͕ଟ͘ͳΔ ŋŋŋ ϑϨʔϜϫʔΫԽͰ͖Δ͔ • ϑϩϯτΤϯυͦ͜Λ 3FBDU &MNͳͲͷϑϨʔϜϫʔΫ͕͍ͬͯΔ ͔ͩΒɺΠϕϯτʹର͢ΔϞ σϧͷঢ়ଶભҠͱɺͦͷঢ়ଶΛදݱ͢ΔϓϨθϯςʔγϣϯͷهड़ʹूதͰ͖Δ • ΠϕϯτͱΠϕϯτͷͭͳ͗߹Θͤ ྫ3FTVMUܕʹΑΔ߹ ΛࣗͰهड़͍ͯ͠Δͷ͕ݱঢ় -
ݱ࣌Ͱͷײ • ্༷ͳ͍ঢ়ଶΛ࡞ΒͣʹࡁΉͨΊɺݎ࿚ • ΑΓෳࡶͳϫʔΫϑϩʔΛ࣮ͨ͠߹ಉ͡ߏʹऩ·Δɻೝෛՙ͕͍ • 3FTVMUܕʹΑΓܭࢉΛܨ͛ΒΕΔΑ͏هड़͢Δྑ͍ڧ੍ྗ͕ಇ͘ – ͨͩ͠ andThen().andThen().asyncAndThen.map()
͕͢͞ʹಡΈͮΒ͍ – )BTLFMMͷ EPه๏ɺ'ͷίϯϐϡςʔγϣϯࣜʹ૬͢Δͷ͕ཉ͍͠ŋŋŋ • ͷ٧Ίସ͑ͷهड़͕ͳ͍ͷ ͱͯ خ͍͠ -
·ͱΊ • ࣌ܥྻʹجͮ͘ঢ়ଶભҠͷએݴͱϑϨʔϜϫʔΫଆʹΑΔঢ়ଶભҠɺௐఀ – ϑϩϯτΤϯυɺͦͷͨΊͷϑϨʔϜϫʔΫͷ࣮͕ॆ࣮͍ͯ͠Δ • ʮએݴతϓϩάϥϛϯάʯͷϓϥΫςΟεɺݱ࣌Ͱܦݧతʹྑ͍ͷ – όοΫΤϯυ։ൃ͜ͷߟ͑ํʹऩᏑ͍ͤͯ͘͞ͷѱ͘ͳ͍ͷͰ ˠͬͯΈͨΒײ৮
– ྲྀߦΔ͔Ͳ͏͔Θ͔Γ·ͤΜ • ϑϩϯτΤϯυ όοΫΤϯυͷύϥμΠϜΪϟοϓΛগͳ͍͖͍ͯͨ͘͠ -
ัଊ • 5ZQF4DSJQUʹΈࠐΈͷ 3FTVMUܕͳ͍ͷͰɺOFWFSUISPXΛͬͨɻଞʹ GQUTͳͲͷީิ͕͋Δ • 3FTVMUܕ XPSLGMPXͷߏ͚ͩͰͳ͋͘ΒΏΔॴͰ͏ • Ұํʮ3FTVMUܕύζϧʯʹ·Δ͕࣌͋Δŋŋŋ
• հΕͳ͔͕ͬͨ 1SPNJTF 3FTVMU"TZODʹΑͬͯ 3FTVMUԽͯ͠߹Ͱ͖Δ • %PNBJO.PEFMJOH.BEF'VODUJPOBM ʹ͍ͭͯ – ॻ੶ͷఏҊख๏ͦͷ··ͩͱτϥϯβΫγϣϯεΫϦϓτʹͳΓڽूੑ͕͘ͳΔɻ ͨͩ͠ *0͖ͪΜͱ͞Ε͍ͯΔͷͰɺΑ Γྑ͍τϥϯβΫγϣϯεΫϦϓτͩͱࢥ͏ ΤϯςΟςΟͷܕͷपΓʹυϝΠϯϩδοΫͷؔΛूΊΔ͜ͱͰͦͷղফ Ͱ͖͍ͯΔ – ͋ΒΏΔϓϩύςΟʹܕΛఆٛ͢ΔυϝΠϯϓϦϛςΟϒతͳख๏Λ࠾͍ͬͯΔ͕ɺͦ͜࠾༻͠ͳ͔ͬͨɻ7BMVF0CKFDUͷΈ /PNJOBMͳܕఆٛΛܕͷϒϥϯυԽ ˞ΦϥΠϦʔͷ 5ZQF4DSJQUຊࢀর ʹΑͬͯߦ͍ͬͯΔ – 3FQPTJUPSZඞཁͳ͍ͱॻ͔Ε͍͕ͯͨɺूΛ͔ͤͬ͘ߏ͍ͯ͠ΔͷͰैདྷ௨Γ 3FQPTJUPSZύλʔϯͰू୯ҐͰͷӬଓԽ Λߦ͍ͬͯΔɻͳ͓ɺ3FQPTJUPSZͷத 1SJTNBΛ͍ͬͯΔ • UZQFͱ JOUFSGBDFͷ͍͚ ŋŋŋ GQUTʹ฿͍ͬͯΔɻಛʹͦ͏͠ͳ͚ΕͳΒ͍ཧ༝ͳ͍ͱࢥ͏ • ͕ؔσϑΥϧτͰΧϦʔԽ͞Εͳ͍ͷํ͕ͳ͍ɻ࣌ંΧϦʔԽͨ͠ͷΛΕͯ·Δ • SFBEPOMZԣணͯ͠ɺͬͯͳ͍ɻ ͪΌΜͱݕ౼͍ͯ͠ͳ͍ -
ࢀߟจݙ • 4DPUU8MBTDIJO ʮ%PNBJO.PEFMJOH.BEF'VODUJPOBMᴷ5BDLMF4PGUXBSF$PNQMFYJUZXJUI%PNBJO%SJWFO %FTJHOBOE'ʯ • +FSFNZ'BJSCBOL ஶ ϠΪͷ͘͞ΒͪΌΜ
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