Building Custom TSLint Rules

Sample code is here: https://github.com/ashfurrow/tsnyc-tslint-rules

Transcript

1. Building Custom TSLint Rules
   Ash Furrow, Artsy
   

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2. whoami
   - Hi I’m Ash
   - Artsy
   - Canadian
   - Recovering iOS developer
   - Photography
   - Guitar
   - Likes type systems
   - Really likes developer tooling
   

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5. TSLint
   - Checks (“lints”) your code for problems
   - There are a bunch of built-in rules
   - Line length
   - Alphabetically ordered imports
   - Variable name consistency
   - Prevent unnecessary type assertions
   - etc
   - And you can build your own!
   

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6. Custom TSLint Rules
   - Rules are just code
   - Rules provide details of what’s wrong
   - Optionally, rules can fix the code automatically ✨
   - Two types of rules:
   - String-based rules
   - AST-based rules
   - So what’s an AST?
   

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7. Abstract Syntax Trees
   - Compiler data type
   - Machine-readable representation of your code
   if (user.isAdmin) {
   return "Hello, Admin."
   } else {
   return "401 lol"
   }
   if user.isAdmin
   return return
   "Hello, Admin" "401 lol"
   

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8. astexplorer.net
   

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9. Demo
   - Okay time for code now please
   

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10. Resources
    - github.com/ashfurrow/tsnyc-tslint-rules (see: STEPS.md)
    - github.com/ashfurrow/tslint-playground (more resources linked to from here)
    

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