Type Safe "Everything"

Transcript

1. Type Safe
   “EVERYTHING”
   @andoshin11

   4. 3. 2020

   #tsc_api_study

   

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2. Who am I ?
   Shin Ando (a.k.a Andy)
   @andoshin11
   - Freelance Full-Stack Developer
   - TypeScript / Vue.js / React / Go / Ruby / Flutter / Terraform / etc…
   - ❤ Code Generation!
   

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3. ● Powerful editor completion
   ● Easy to analyze code base using AST
   ● Type-level programming
   ● Overall durability
   ● Maintainable
   ● Scalable
   ● F**king AWESOME!!
   We all love TypeScript, eh? ❤
   

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4. However...
   

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5. Not everyone speaks TypeScript (just yet...)
   

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6. Not everyone speaks TypeScript (just yet...)
   ● Other programming languages (Go, Ruby, Python, Java, etc...)
   ● Query based languages (a.k.a Database)
   ● Statically defined specs (YAML, CSV, Markdown, Excel)
   ● etc...
   

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7. Not everyone speaks TypeScript (just yet...)
   ● Other programming languages (Go, Ruby, Python, Java, etc...)
   ● Query based languages (a.k.a Database)
   ● Statically defined specs (YAML, CSV, Markdown, Excel)
   ● etc...
   

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8. Solution (we need)
   

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9. Basic aproach
   Parser
   Transformer
   TS Compiler
   1. Parse input and tokenize into JSON
   2. Transform tokens to TypeScript AST
   3. Validate AST and emit useful code
   Outcome
   

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11. Working Projects
    

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12. ① Typing Database Schema (db-recon)
    ● db-recon ( https://github.com/andoshin11/db-recon )
    ● Generates type-safe db client for Node.js application
    ● Supports MySQL and MSSQL currently
    

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13. ① Typing Database Schema (db-recon)
    

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14. ① Typing Database Schema (db-recon)
    

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15. ① Typing Database Schema (db-recon)
    

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16. ① Typing Database Schema (db-recon)
    TODO:
    ● Create SQL-to-AST parser
    ● Get semantic diagnostics for raw SQL literal string
    ( ts-sql-plugin requires DSL )
    ● Rewrite ejs templates with TS Compiler API
    

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17. ② Typing API Request/Response (squelette)
    ● squelette ( https://github.com/andoshin11/squelette )
    ● Generates type definitions for API request/response from
    Open API spec
    ● Toolchain to build your own type-safe API client
    

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18. ② Typing API Request/Response (squelette)
    

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19. ② Typing API Request/Response (squelette)
    

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20. ② Typing API Request/Response (squelette)
    

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21. ② Typing API Request/Response (squelette)
    

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22. ② Typing API Request/Response (squelette)
    TODO:
    ● Rewrite remaining ejs templates with TS Compiler API
    ● Improve parser and AST format
    

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23. Latest addition
    

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24. Improving DX for express.js
    

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25. Remaining Pains...
    

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26. Remaining Pains...
    need manual mapping
    need to define types
    may contain typo
    

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27. Leads to fatal error in future...
    

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28. What if...
    

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29. All handlers are typed like a magic ‍♂
    

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31. Introducing...
    

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32. typed-oax
    

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33. Generate express.d.ts from Open API
    

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34. Generate express.d.ts from Open API
    

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35. Generate express.d.ts from Open API
    

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36. DEMO
    

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37. typed-oax
    TODO:
    ● Separate handler types by HTTP Method
    ● Wrap with TS Plugin?
    

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