Dependency Injection in Scala

青山エンジニア勉強交流会～Scala勉強会～ (2017/12/04)
「DIとは何か」について軽く説明した後、ScalaのDI手法を4つ(Manual DI, Cake Pattern, MacWire, Guice)紹介しました

Transcript

1. Dependency Injection in Scala גࣜձࣾϑΝϯίϛϡχέʔγϣϯζ ੴ઒ ༟थ
2. Profile • ϑΝϯίϛೖࣾ4೥໨ • Scalaྺ2೥൒͘Β͍ (લ: Java, Ruby, Perl,PHP, etc.) • nend, nex8, viidleͷ഑৴γεςϜߏஙΛ୲౰ • ࠷ۙ͸ϒϩοΫνΣʔϯͷษڧΛͨ͠Γ ੴ઒ ༟थ Yuki Ishikawa
3. Dependency Injection (DI) ͱ͸Կ͔ʁ
4. Dependency Injection (DI) ͱ͸Կ͔ʁ ίϯϙʔωϯτؒͷґଘؔ܎ΛϓϩάϥϜͷ ιʔείʔυ͔Βഉআ͠ɺ֎෦ͷઃఆϑΝΠ ϧͳͲͰ஫ೖͰ͖ΔΑ͏ʹ͢Διϑτ΢ΣΞ ύλʔϯͰ͋Δɻ WikipediaΑΓ https://ja.wikipedia.org/wiki/ґଘੑͷ஫ೖ
5. "E$POUSPMMFS "E4FSWJDF "E4FSWJDF*NQM Dependency Injection (DI) ͱ͸Կ͔ʁ .PEVMF
   *OKFDUPS AdController: ޿ࠂϦΫΤετͷϋϯυϦϯά AdService: ࠷దͳ޿ࠂͷબग़ϩδοΫ
6. Dependency Injection (DI) ͱ͸Կ͔ʁ Manual DIʹΑΔ࣮૷ྫɻDIͷํ๏͸Կछྨ΋ଘࡏ͢Δ
7. Dependency Injection (DI) ͱ͸Կ͔ʁ Manual DIʹΑΔ࣮૷ྫɻDIͷํ๏͸Կछྨ΋ଘࡏ͢Δ wiring(഑ઢ)
8. Կ͕خ͍͠ͷ?
9. Կ͕خ͍͠ͷʁ ‣ ݁߹౓ͷ௿ԼɾίϯϙʔωϯτԽͷଅਐ ‣ ୯ମςετ͕͠΍͘͢ͳΔ
10. ScalaͰDI͢Δํ๏
11. • MacWire • Guice • Spring • Scaldi • SubCut • Freestyle
 (Free Monad & Taggless Final) Pure Scala Library • Manual DI • Cake Pattern • Reader Monad • Free Monad • Tagless Final ScalaͷDIύλʔϯ
12. ͕࣌ؒ͋·Γແ͍ͷͰ • Manual DI • Cake Pattern • MacWire • Guice ͷ̐छྨΛ঺հ͠·͢ʂ
13. Manual DI (Constructor Injection) • ίϯετϥΫλҾ਺Λ࢖ͬͯख࡞ۀͰ഑ઢ • Ұ൪؆୯ʹDI͢Δํ๏
14. Manual DI (Constructor Injection) ख࡞ۀͰ഑ઢ͢Δ
15. Manual DI (Constructor Injection) ςετ͢Δͱ͖͸ܧঝͯ͠mock/stubͰ্ॻ͖͢Ε͹OK
16. Manual DI (Constructor Injection) Pros Cons • Ұ൪खܰʹ࢝ΊΒΕΔํ๏ • Compile-time DI • Pure Scala • ґଘؔ܎͕ଟ͍ͱ഑ઢ࡞ۀ͕ͭΒ͍ খن໛ͷϓϩδΣΫτͳΒManualͰे෼!!
17. Cake Pattern • ίϯετϥΫλҾ਺Λ࢖༻͠ͳ͍໘ന͍Ξϓϩʔν ‣ ࣗ෼ܕΞϊςʔγϣϯ΍ܧঝͰDI͢Δ • nendͰ࠾༻͍ͯ͠Δ • આ໌͕೉͍͠
18. Cake Pattern ίϯϙʔωϯτΛ࡞੒
19. Cake Pattern MixinͰΦϒδΣΫτΛ஫ೖ͢Δ
20. Cake Pattern Minimal Cake Pattern υϫϯΰΞΧ΢ϯτγεςϜͰ࠾༻͞Ε͍ͯΔख๏ ʢࣗ෼ܕΞϊςʔγϣϯ͕ొ৔͠ͳ͍ͷͰཧղ͠΍͍͢ʣ https://qiita.com/pab_tech/items/1c0bdbc8a61949891f1f
21. Cake Pattern Pros Cons • Compile-time DI • Pure Scala • େྔͷϘΠϥʔϓϨʔτ • ॊೈੑ͕௿͍ ‣ Component͕ΠϯελϯεΛ͔̍ͭ࣋ͯ͠ͳ͍ͷͰɺ2ͭͷಉ͡ ܕʹґଘͰ͖ͳ͍ • ύϑΥʔϚϯεɾίϯύΠϧ࣌ؒʹѱӨڹʁ(ະݕূ)
22. MacWire • Scala༻ϥΠϒϥϦ • ϚΫϩͰ഑ઢͯ͘͠ΕΔ • viidleͰ࠾༻͍ͯ͠Δ • Adam Warski͞Μ͕࡞ͬͯΔ ‣ ϒϩάͰScalaͷDIؔ࿈ͷهࣄΛެ։ͯ͠Δ ‣ ࠷ۙ͸sttpͱ͔࡞ͬͯΔ
23. MacWire wire͢Δ͚ͩͰɺ͋ͱ͸ϚΫϩ͕΍ͬͯ͘ΕΔ
24. MacWire wireSetͰෳ਺ΦϒδΣΫτͷSetԽ͕Մೳ
25. MacWire scala-commonͰλά෇͚͕Մೳ (λά෇͚ͨ͘͠ͳ͍৔߹͸Manual DIͱซ༻ͯ͠΋ྑ͍)
26. MacWire Pros Cons • ϘΠϥʔϓϨʔτ͕গͳ͍ • Compile-time DI • ϚΫϩ (ڧ͍ͯݴ͑͹)
27. Guice • Java༻DIϑϨʔϜϫʔΫ • ҆৺ͷGoogle੡ • ߴػೳͰग़དྷΔࣄ͕ଟ͍ • Runtime DI
28. Guice ஫ೖ͍ͤͨ͞ͱ͜Ζʹ @Inject Λ͚ͭΔ
29. Guice @ImplementedBy Ͱ࣮૷Λࢦఆ͢Δ or bind Ͱ഑ઢ͢Δ
30. Guice @Named, annotatedWithͰλά෇͚΋Մೳ
31. Guice @Named, annotatedWithͰλά෇͚΋Մೳ
32. Guice ProviderͰॊೈͳDI͕Մೳ
33. Guice Pros Cons • ߴػೳͰॊೈੑ͕ߴ͍ • ϘΠϥʔϓϨʔτ͕গͳ͍ • ࣮ߦ࣌ʹ഑ઢΛίϯτϩʔϧͰ͖Δ • JavaͰ࢖ͬͯͨਓʹ͸ೃછΈ΍͍͢ • Runtime DI • ֶशίετ͕ߴ͍
34. ͳʹΛ࢖͑͹ྑ͍͔ʁ
35. ԿΛ࢖͑͹ྑ͍͔ʁ ͓޷͖ͳͷΛͲ͏ͧ
36. ͓͢͢Ί • ࠷ॳ͸Manual DI͔Β࢝ΊΔͷ͕Φεεϝ • Compile-time DIΛ࢖ͬͨ΄͏͕҆શ • Guice͸ڽͬͨࣄ͕͍ͨ͠৔߹ʹ