Type Safe "Everything"

Transcript

1. Type Safe “EVERYTHING” @andoshin11
 4. 3. 2020
 #tsc_api_study


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!

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? ❤

4. However...

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

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...

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...

8. Solution (we need)

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
10. None

11. Working Projects

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

13. ① Typing Database Schema (db-recon)

14. ① Typing Database Schema (db-recon)

15. ① Typing Database Schema (db-recon)

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

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

18. ② Typing API Request/Response (squelette)

19. ② Typing API Request/Response (squelette)

20. ② Typing API Request/Response (squelette)

21. ② Typing API Request/Response (squelette)

22. ② Typing API Request/Response (squelette) TODO: • Rewrite remaining ejs

    templates with TS Compiler API • Improve parser and AST format

23. Latest addition

24. Improving DX for express.js

25. Remaining Pains...

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

    contain typo

27. Leads to fatal error in future...

28. What if...

29. All handlers are typed like a magic ‍♂

30. None

31. Introducing...

32. typed-oax

33. Generate express.d.ts from Open API

34. Generate express.d.ts from Open API

35. Generate express.d.ts from Open API

36. DEMO

37. typed-oax TODO: • Separate handler types by HTTP Method •

    Wrap with TS Plugin?