NestJSのDIコンテナで作るクリーンなレイヤー境界

NestJS Meetup Online #2 にて発表した内容です。

https://nest-jp.connpass.com/event/244015/

1. גࣜձࣾΧέϋγɹ໦ଜ
   জ޺
   /FTU+4ͷ%*ίϯςφͰ࡞ΔΫϦʔϯͳϨ ΠϠʔڥք /FTU+4
   NFFUVQ
   0OMJOF
   ɹ
   
2. ࢹௌऀ૚ɾಡऀ૚ͷ૝ఆ w ҎԼͷ͍ͣΕ͔ʹ֘౰
   w /FTU+4Ͱ8FCΞϓϦέʔγϣϯΛ૊Μͩ͜ͱ͕͋Δ
   w /FTU+4ͷ1SPWJEFS.PEVMFΛ৮ͬͨ͜ͱ͕͋Δ
   w ΦϒδΣΫτࢦ޲Ͱͷઃܭɾ։ൃܦݧ͕͋Δ
3. ࣗݾ঺հ w גࣜձࣾΧέϋγ
   d
   w ҩྍ඼ൃ஫ɾ؅ཧ࠷దԽྖҬͷ৽نࣄۀͷ্ཱͪ͛Λ୲౰த
   w ιϑτ΢ΣΞΤϯδχΞ
   
   σʔλΤϯδχΞ
   
   ΞʔΩςΫτ
   w Χέϋγͱ5ZQF4DSJQU
   w גࣜձࣾΧέϋγ
   Y
   5ZQF4DSJQU
   "EWFOU
   $BMFOEBS
   
   w ͳͥόοΫΤϯυ5ZQF4DSJQU͔ʁٕज़બఆഎܠͱ࣮ફྫΛ঺հ͠·͢
   ໦ଜ
   জ޺ ͖ΉΒ
   ͖͋ͻΖ ˞
   ܦྺͷৄࡉ͸/FTU+4
   .FFUVQ
   0OMJOFͷΠϕϯτϖʔδʹهࡌ͍ͯ͠·͢
4. 5XJUUFS
   IUUQTUXJUUFSDPNLJNVUZBN
   .FEJVN
   IUUQTLJNVUZBNNFEJVNDPN
   4QFBLFS%FDL
   IUUQTTQFBLFSEFDLDPNLJNVUZBN
   (JUIVC
   IUUQTHJUIVCDPNLJNVUZBN 'PMMPX
   .F
5. ΞδΣϯμ  ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ͑ํ
    /FTU+4ͷ%*ίϯςφͷ࢓૊Έ
    ϨΠϠʔڥքΛߏ੒͢Δ औΓѻΘͳ͍͜ͱ w ΫϦʔϯΞʔΩςΫνϟͷਂ͍આ໌
   w υϝΠϯϞσϦϯάͷ࢓ํ ηΫγϣϯ
6. ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ ͑ํ ηΫγϣϯ
7. w ΫϦʔϯΞʔΩςΫνϟͰ༗໊ͳਤͰ͢ɻ
   w ͜ΕΒͷಉ৺ԁͷ಺ଆʹ͍͘΄Ͳιϑτ΢ΣΞͱ ্ͯ͠ҐϞδϡʔϧʹͳΔ͜ͱ͕ࣔ͞Ε͍ͯ·͢ɻ
   w υϝΠϯۦಈઃܭͷจ຺ͩͱɺ&OUJUJFT͸ศ্ٓυ ϝΠϯϞσϧͱදݱ͢Δ৔߹͕͋Γ·͢ɻ
   w ಉ৺ԁͷ࿮ΛϨΠϠʔڥքͱݺͼ·͢ɻ
   w ಉ৺ԁͷ࿮Λԣஅ͢Δʮˠʯ͸ґଘؔ܎Ͱ͢ɻ ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ͑ํ ΫϦʔϯΞʔΩςΫνϟ IUUQTCMPHDMFBODPEFSDPNVODMFCPCUIFDMFBOBSDIJUFDUVSFIUNM
8. ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ͑ํ ґଘؔ܎ٯసͷݪଇ %FQFOEFODZ
   *OWFSTJPO
   1SJODJQMF l
   ্ҐϞδϡʔϧ͸͍͔ͳΔ΋ͷ΋ԼҐϞδϡʔϧ ͔Β࣋ͪࠐΜͰ͸ͳΒͳ͍ɻ૒ํͱ΋ந৅ʢྫͱ͠ ͯΠϯλʔϑΣʔεʣʹґଘ͢Δ΂͖Ͱ͋Δɻz
   ˞
   l
   ந৅͸ৄࡉʹґଘͯ͠͸ͳΒͳ͍ɻৄࡉʢ۩৅త ͳ࣮૷಺༰ʣ͕ந৅ʹґଘ͢Δ΂͖Ͱ͋Δɻz
   ˞
   ґଘؔ܎ٯసύλʔϯͰ͸ɺΠϯλʔϑΣʔεΛ஥հ ͤ͞Δ͜ͱͰ্ҐϞδϡʔϧͷґଘΛճආ͍ͯ͠· ͢ɻ ,MPES
   
   ౤ߘऀࣗ਎ʹΑΔஶ࡞෺
   $$
   දࣔܧঝ
   
   IUUQTDPNNPOTXJLJNFEJBPSHXJOEFYQIQ DVSJEʹΑΔ ,MPES
   
   ౤ߘऀࣗ਎ʹΑΔஶ࡞෺
   $$
   දࣔܧঝ
   
   IUUQTDPNNPOTXJLJNFEJBPSHXJOEFYQIQ DVSJEʹΑΔ ӈ্ը૾
   ӈԼը૾
   ˞ IUUQTKBXJLJQFEJBPSHXJLJґଘੑٯసͷݪଇ ैདྷͷϨΠϠʔύλʔϯ ґଘؔ܎ٯసύλʔϯ
9. w ґଘؔ܎ٯసͷݪଇʹैͬͨઃܭΛ͢Δͱɺ࠷ऴ తʹΠϯλʔϑΣʔεͷ࣮૷Λඥ෇͚Δඞཁ͕ग़ͯ ͖·͢ɻͦ͜Ͱɺґଘੑͷ஫ೖ %* Λߦ͍·͢ɻ
   w ্ͷίʔυ͸ɺίϯετϥΫλͰґଘੑΛ஫ೖ͢ ΔྫͰ͢ ίϯετϥΫλ%* ɻ
   w %*ͱ͸ɺґଘؔ܎ΛΫϥεؔ਺ͷ֎͔Β౉͢͜ͱ Ͱ͢ɻ
   w ͳ͓ɺԼͷίʔυ͸ɺ.FDIBOJTN಺෦Ͱ1PMJDZͷ ۩৅Ϋϥε͕ґଘͯ͠ɺґଘੑͷz஫ೖzʹ͸ͳͬͯ ͍·ͤΜɻ ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ͑ํ ґଘੑͷ஫ೖ %FQFOEFODZ
   *OKFDUJPO export class MechanismService { constructor(private policyService: IPolicyService) { } // ུ } export class MechanismService { private policyService: IPolicyService = new PolicyService( ) // ུ }
10. w %*Λ࢖ͬͨΫϥεઃܭΛਐΊΔͱɺґଘؔ܎Λղ ܾ͢ΔӈͷΑ͏ͳίʔυ͕ੜ·Ε·͢ɻ
    w Ϋϥε͕গͳ͍͏ͪ͸໰୊ʹͳΓ·ͤΜ͕ɺ૿͑ ͖ͯͨ࣌͸ෆཁͳෳࡶੑΛੜΉ৔߹͕͋Γ·͢ɻ
    w %*ίϯςφ͸ӈͷίʔυΛॻ͔ͣʹґଘؔ܎ͷϏ δωεϩδοΫͷ֎ଆͰ؅ཧ͢Δ͜ͱ͕Ͱ͖· ͢ɻ
    w ͦͯ͠ɺ%*ίϯςφ͸/FTU+4ͷओཁͳػೳͷͭ Ͱ͢ɻ ΫϦʔϯͳϨΠϠʔڥքΛ૊ΉͨΊͷߟ͑ํ %*ίϯςφ͸ԿΛղܾ͢Δ͔ʁ new UtilityService ( new MechanismService ( new PolicyService( ) ) )
11. /FTU+4ͷ%*ίϯςφͷ࢓૊Έ ηΫγϣϯ
12. w ·ͣ͸؆୯ͳྫ͔Βɻ
    w $BUT4FSWJDFͷґଘؔ܎͸ɺ!.PEVMFΛӈͷΑ͏ ʹఆٛ͢Ε͹%*Ͱ͖·͢ɻ
    w ͜ͷྫ͸ɺ$BUT4FSWJDFzΫϥεzΛ$BUT$POUSPMMFS ͰίϯετϥΫλ%*͍ͯ͠·͢ɻ /FTU+4ͷ%*ίϯςφͷ࢓૊Έ 1SPWJEFS @Controlle r class CatsService { } @Controller("cats") class CatsController { constructor(private catsService: CatsService) { } // ུ } @Module( { controllers: [CatsController] , providers: [CatsService] , } ) export class AppModule {}
13. w ΠϯλʔϑΣʔεͷ৔߹͸ɺ޻෉͕ඞཁͰ͢ɻ
    w +BWB4DSJQU͸ΠϯλʔϑΣʔεΛαϙʔτͯ͠ ͍ͳ͍ͨΊɺ5ZQF4DSJQUΛ+BWB4DSJQUʹίϯ ύΠϧ͢ΔͱɺΠϯλʔϑΣʔεͷఆٛ͸ফࣦ ͠·͢ɻ
    w τʔΫϯ ྫͰ͸$"54@4&37*$&@50,&/ Ͱ /FTU+4ͷ*OKFDUFSͰࣝผՄೳͳঢ়ଶʹ͢Δඞཁ͕ ͋Γ·͢ɻ /FTU+4ͷ%*ίϯςφͷ࢓૊Έ 1SPWJEFS interface ICatsService { } class CatsService implements ICatsService { } const CATS_SERVICE_TOKEN = "CATS_SERVICE_TOKEN" ; class CatsController { constructor ( @Inject(CATS_SERVICE_TOKEN ) private catsService: ICatsServic e ) { } // ུ } export const CatServiceProvider: Provider = { provide: CAT_SERVICE_TOKEN , useClass: CatsService , } ; @Module( { controllers: [CatsController] , providers: [CatServiceProvider] , } ) export class AppModule { }
14. /FTU+4ͷ%*ίϯςφͷ࢓૊Έ !.PEVMFͱ͸Կ͔ʁ .PEVMF
    # .PEVMF
    " FYQPSUT JNQPSUT JNQPSUT 1SPWJEFS 1SPWJEFS $POUSPMMFS QSPWJEFST /FTU+4ͷΠϯδΣΫλʹΑͬͯΠϯελϯ εԽ͞Εɺগͳ͘ͱ΋Ϟδϡʔϧ಺Ͱڞ༗ ͞ΕΔ DPOUSPMMFST .PEVMF಺ͷΠϯελϯεԽ͢Δඞཁ͕͋Δ $POUSPMMFSҰཡ JNQPSUT ͜ͷϞδϡʔϧʹFYQPSU͢ΔผͷϞδϡʔ ϧͷҰཡ FYQPSUT ผͷϞδϡʔϧͰ͜ͷϞδϡʔϧΛJNQPSU ͢ΔͨΊͷɺެ։͢ΔϓϩόΠμٴͼτʔ ΫϯͷϦετ
15. ϨΠϠʔڥքΛߏ੒͢Δ ηΫγϣϯ
16. ϨΠϠʔڥքΛߏ੒͢Δ IUUQTCMPHDMFBODPEFSDPNVODMFCPCUIFDMFBOBSDIJUFDUVSFIUNM ߏ੒͢ΔΫϥεਤ
17. ϨΠϠʔڥքΛߏ੒͢Δ ߏ੒͢ΔΫϥεਤ w ֤ϨΠϠʔຖ EPNBJOVTF$BTF QSJNBSZ"EBQUPSTFDPOEBSZ"EBQUPS ʹͦΕͧ Ε.PEVMFΛ࡞੒͠·͢
    w ͦΕΒΛ࠷ऴతʹ.PEVMFΛଋͶ·͢ɻ
    w <ิ଍>
    QSJNBSZͱTFDPOEBSZͱ͸ʁ
    w ΫϦʔϯΞʔΩςΫνϟͷલਐͱͳͬͨ 1PSUT"EBQUPSTΞʔΩςΫνϟͷ༻ޠͰ ͢ɻ
    w QSJNBSZ͸ʮۦಈ͢ΔʯΞμϓλ
    w TFDPOEBSZ͸ʮۦಈ͞ΕΔʯΞμϓλ
18. w 3FQPTJUPSZ΍3FRVFTUFS͸*'ͷΈͰ͢ɻ
    w ۩ମతͳ࣮૷Λ͢ΔͱΞμϓλ૚ٴͼͦΕΑ Γ΋֎ͷԁʹґଘͯ͠͠·͏ͨΊͰ͢ɻ
    w Ұ൪্ҐϞδϡʔϧʹͳΔͨΊz஫ೖz͢Δґଘ͸ ͳ͍ͨΊɺ.PEVMF͸͋Γ·ͤΜɻ
    w ͳ͓ɺτʔΫϯ͸Ϣʔεέʔε૚ͷ࣮૷Ͱ࢖͏ͨ Ίɺ͜͜ʹ഑ஔ͍ͯ͠·͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ υϝΠϯ૚ EPNBJO export type Cat = Readonly< { id: CatId ; name: CatName ; age: CatAge ; }> ; export const CAT_REPOSITORY_TOKEN = 'CAT_REPOSITORY_TOKEN' ; export interface ICatRepository { store(cat: Cat): Promise<void> ; } export const CAT_REQUESTER_TOKEN = 'CAT_REQUESTER_TOKEN' ; export interface ICatRequester { get(catId: CatId): Promise<Cat | undefined> ; }
19. w ʮೣΛड͚औΔʯͱ͍͏ϢʔεέʔεΛ૝ఆͨ͠ ࣮૷Ͱ͢ɻ
    w 6TF$BTF͸*'Ͱɺͦͷ࣮૷Ϋϥε͸ *OUFSBDUPS Ͱ͢ɻ
    w *OUFSBDUPSͰ͸υϝΠϯ૚Ͱఆٛͨ͠*'Λίϯε τϥΫλͷҾ਺ʹఆ͍ٛͯ͠·͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ Ϣʔεέʔε૚ 6TF$BTF export interface UseCase<In, Out> { run(input: In): Promise<Out> ; } export type Input = Readonly< { catId: CatId ; }> ; export type Output = Omit<Cat, 'id'> ; export type ReceiveCatUseCase = UseCase<Input, Output> ; export const RECEIVE_CAT_USECASE_TOKEN = 'RECEIVE_CAT_USECASE_TOKEN' ; @Injectable( ) export class ReceiveCatInteractor implements ReceiveCatUseCase { constructor ( @Inject(CAT_REPOSITORY_TOKEN ) private catRepository: ICatRepository , @Inject(CAT_REQUESTER_TOKEN ) private catRequester: ICatRequester , ) { } async run({ catId }: Input): Promise<Output> { const cat = await this.catRequester.get(catId); // ུ } }
20. ϨΠϠʔڥքΛߏ੒͢Δ Ϣʔεέʔε૚ 6TF$BTF w ηΧϯμϦʔΞμϓλͷΫϥε ྘ Λ࣮૷ͱͯ͠ ࠾༻͢Δ͜ͱʹ͢Δ৔߹͸ɺηΧϯμϦΞμϓλ ͷ.PEVMFΛJNQPSU͠·͢ɻ
    w ͜ΕΛ౿·͑ͯ࣍ͷϖʔδͰ͸.PEVMFΛ࡞੒͠ ·͢ɻ
21. w ηΧϯμϦʔΞμϓλͷ.PEVMF ޙड़ ΛJNQPSU ͍ͯ͠·͢
    w ϢʔεέʔεΛଞͷ.PEVMFͰར༻Ͱ͖ΔΑ͏ʹ ϓϩόΠμΛFYQPSU͍ͯ͠·͢
    w ϓϥΠϚϦΞμϓλͷ.PEVMF ޙड़ ͰJNQPSU ͠·͢ɻ
    w <ิ଍>
    6TF$BTF.PEVMF͸ΠϯλʔϑΣʔεΞμ ϓλʹґଘ͍ͯ͠·͕͢ɺϩδοΫ͕ґଘ͍ͯ͠ ΔΘ͚Ͱ͸͋Γ·ͤΜɻ ϨΠϠʔڥքΛߏ੒͢Δ Ϣʔεέʔε૚ 6TF$BTF export const ReceiveCatUseCaseProvider: Provider = { provide: RECEIVE_CAT_USECASE_TOKEN , useClass: ReceiveCatInteractor , } ; @Module( { imports: [AdaptorMemoryStoreModule, AdaptorPetShopApiModule] , providers: [ReceiveCatUseCaseProvider] , exports: [ReceiveCatUseCaseProvider] , } ) export class UseCaseModule { }
22. w υϝΠϯ૚ͷϦϙδτϦͷ*'Λ࣮૷͍ͯ͠·͢ɻ
    w ϦϙδτϦͷϓϩόΠμΛଞͷ.PEVMFͰ׆༻Ͱ ͖ΔΑ͏ʹFYQPSU͍ͯ͠·͢ɻ
    w Ϣʔεέʔεͷ.PEVMFͰJNQPSU͠·͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ ΠϯλʔϑΣʔεΞμϓλ૚ 4FDPOEBSZ
    "EBQUPS @Injectable( ) export class CatRepository implements ICatRepository { store(cat: Cat): Promise<void> { // ུ } } export const CatRepositoryProvider: Provider = { provide: CAT_REPOSITORY_TOKEN , useClass: CatRepository , } ; @Module( { providers: [CatRepositoryProvider] , exports: [CatRepositoryProvider] , } ) export class AdaptorMemoryStoreModule { }
23. w $BU$POUSPMMFSͷ࣮૷Ͱ͢ɻ
    w 6TF$BTF͸*'ͱ1SFTFOUFSͷΫϥεΛίϯετ ϥΫλͰఆ͍ٛͯ͠·͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ ΠϯλʔϑΣʔεΞμϓλ૚ 1SJNBSZ
    "EBQUPS @Injector( ) export class CatPresenter { } @Controller('/cat' ) export class CatController { constructor ( @Inject(RECEIVE_CAT_USECASE_TOKEN ) private receiveCatUseCase: ReceiveCatUseCase , private catPresenter: CatPresenter , ) { } @Put(':id' ) async receive(@Param('id') id: string): Promise<CatViewModel> { // ུ } }
24. ϨΠϠʔڥքΛߏ੒͢Δ ΠϯλʔϑΣʔεΞμϓλ૚ 1SJNBSZ
    "EBQUPS w $POUSPMMFS ੨ ͷґଘؔ܎Λղܾ͢ΔͨΊʹɺ *OUFSBDUPSͷϓϩόΠμʔΛؚΉϢʔεέʔεͷ .PEVMF͕ඞཁʹͳΓ·͢ɻ
    w ·ͨɺ͜ͷྫͰ͸1SFTFOUFSͷґଘؔ܎΋ղܾ͢ Δඞཁ͕͋Γ·͢ɻ
    w ͜ΕΛ౿·͑ͯ࣍ͷϖʔδͰ͸.PEVMFΛ࡞੒͠ ·͢ɻ
25. w Ϣʔεέʔεͷ.PEVMFΛJNQPSUͯ͠ɺ $POUSPMMFSͷίϯετϥΫλ%*͍ͯ͠·͢ɻ
    w DPOUSPMMFSTʹίϯτϩʔϥʔͷࢦఆΛ͍ͯ͠· ͢ɻ
    w 1SFTFOUFSΫϥεΛQSPWJEFSTʹࢦఆ͍͠·͢ɻ
    w <ิ଍>
    ͜͜Ͱ͸Ϣʔεέʔεͷ*'ʹґଘ͍ͯ͠· ͕͢ɺϢʔεέʔεͷ*'Λ੾Βͣʹ۩৅Ϋϥεͷ ࢦఆͰ΋໰୊͋Γ·ͤΜɻ
    w *'ʹґଘ͍ͤͯ͞Δͷ͸$POUSPMMFSͷςελ ϏϦςΟΛ޲্ͤ͞ΔͨΊͰ͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ ΠϯλʔϑΣʔεΞμϓλ૚ 1SJNBSZ
    "EBQUPS @Module( { imports: [UseCaseModule] , controllers: [CatController] , providers: [CatPresenter] , } ) export class AdaptorWebApiModule { }
26. w ࠷ऴతʹ"QQ.PEVMFͰࠓ·Ͱ࡞੒ͨ͠.PEVMF ΛJNQPSU͠·͢
    w ηΧϯμϦʔΞμϓλ͸6TF$BTF.PEVMFͰ JNQPSU͞Ε͍ͯΔͨΊ͜͜Ͱ͸ෆཁͰ͢ɻ
    w "QQ.PEVMFΛ/FTU'BDUPSZDSFBUFʹ౉ͯ͠׬ ੒Ͱ͢ɻ ϨΠϠʔڥքΛߏ੒͢Δ "QQ.PEVMF @Module( { imports: [UseCaseModule, AdaptorWebApiModule] , } ) export class AppModule { } export async function main() { const app = await NestFactory.create(AppModule) ; await app.listen(80, '0.0.0.0') ; }
27. ࠷ޙʹ
28. ࠷ޙʹ w ΫϦʔϯͳϨΠϠʔڥքΛ࡞ΔͨΊʹɺґଘؔ܎ٯసͷݪଇΛ׆༻͠ґଘؔ܎Λ஫ೖ͠·͢ɻ
    w %*ίϯςφΛ࢖͏ͱɺ࣮૷ͱઃఆΛ෼͚ͯґଘؔ܎ͷ഑ઢ͕Ͱ͖·͢ɻ
    w /FTU+4ͷ.PEVMFTΛ࢖͑͹ґଘؔ܎ͷ஫ೖͷ෼ׂ౷࣏͕ՄೳͰ͢ɻ
    w ࠓճ͸ϨΠϠʔผʹ഑ઢͷ෼ׂ౷࣏Λ͠·ͨ͠ɻ
    w αϯϓϧίʔυ͸ҎԼ
    w IUUQTHJUIVCDPNLJNVUZBNOFTUKTDMFBOBSDIJUFDUVSFUSFF ·ͱΊ
29. ࠷ޙʹ w ૊Έํͷߟ͑ํ͸ಉ͡Ͱ͕͢ɺ͜͜Ͱઆ໌ͨ͠ͷ͸ύλʔϯͰ͢ɻ
    w ϓϩδΣΫτͷঢ়گ΍ϓϩμΫτͷಛ௃ʹΑͬͯͲ͏͍͏ߏ੒ʹ͢Δ͔͸ݕ౼͠·͠ΐ͏ɻ
    w ͨͩ͠ɺߏ੒Λ૊Ή্Ͱͷߟ͑ํ͸ಉ͡Ͱ͢ɻ
    w lΞʔΩςΫνϟͷϧʔϧ͸ͲΕ΋ಉ͡Ͱ͋Δʂz
    ˞ ஫ҙॻ͖ ˞
    3PCFSU
    $
    .BSUJO
    
    ʰ$MFBO
    "SDIJUFDUVSF
    ୡਓʹֶͿιϑτ΢ΣΞͷߏ଄ͱઃܭʱ
    ʮংจʯΑΓ
30. ࠷ޙʹ 8F
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