Type Safe "Everything"

Transcript

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


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   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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   • 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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   However...

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   Not everyone speaks TypeScript (just yet...)

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   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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   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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   Solution (we need)

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   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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    None
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    Working Projects

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    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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    ① Typing Database Schema (db-recon)

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    ① Typing Database Schema (db-recon)

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    ① Typing Database Schema (db-recon)

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    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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    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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    ② Typing API Request/Response (squelette)

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    ② Typing API Request/Response (squelette)

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    ② Typing API Request/Response (squelette)

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    ② Typing API Request/Response (squelette)

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

    templates with TS Compiler API • Improve parser and AST format
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    Latest addition

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    Improving DX for express.js

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    Remaining Pains...

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

    contain typo
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    Leads to fatal error in future...

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    What if...

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    All handlers are typed like a magic ‍♂

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    None
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    Introducing...

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    typed-oax

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    Generate express.d.ts from Open API

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    Generate express.d.ts from Open API

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    Generate express.d.ts from Open API

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    DEMO

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

    Wrap with TS Plugin?