Suggestion Backlog Slog, 10/30/2017

[RyanCavanaugh]

• Tuple types accepting incorrect data #19463 Fixed tuple length
• Switch is considered exhaustive or not based on the code after it #18882 Ignore trailing declarations when detecting final switch
• Suggestion: Noninferential type parameter usage #14829 Lower/higher-priority inference sites
• Support merging classes and modules across files #3802 Allow cross-file class/namespace merges
• Suboptimal compilation for rest parameters #19182 Move rest arg array copy to first use
• Private Member Minification Design Proposal #16037 Minify private members
• Treat assignments to properties on functions as valid declarations #15868 Allow Salsa-style property assignment declarations on functions
• Expose configuration hook for custom module resolution #18896 Allow plugins for module resolution
• Allow trailing commas in type parameter/argument lists #16152 Allow trailing commas in type parameter + argument lists
• Is it really truly wrong to have an empty array for files in the config? #12762 Allow empty file list in tsconfig

[RyanCavanaugh]

• Tuple types accepting incorrect data #19463 Fixed tuple length
  • Try it?
  • Should we make the whole thing ReadonlyArray<T> ?
    • Bigger breaking change
  • What are people using these for?
  • Only enable this behavior on --strictTuples ? --strict ?
  • Painted into a corner because non-mutating array refs are often not ReadonlyArray<T>
  • But the elements themselves should still be mutable -- FixedOrderArray<T>
  • Is there a real payoff here?
  • Find out what the heck was going on with the originating bug
• Switch is considered exhaustive or not based on the code after it #18882 Ignore trailing declarations when detecting final switch
  • Ignore SEF declarations when scanning to see if the switch is final
  • Ignore use case 2; use case 3 is compelling
  • 👍
• Suggestion: Noninferential type parameter usage #14829 Lower/higher-priority inference sites
  • Type Infer<T> that gives a priority bump
  • Type NoInfer<T> that gives a priority penalty
  • Might go along with union type inference for generics
  • Discuss more later
• Support merging classes and modules across files #3802 Allow cross-file class/namespace merges
  • Who wrote that error message?
    • A New Yorker
      • Excuse me, do you know where the library is at?
        • Here at Harvard, we do not end our sentences with prepositions
          • [punchline]
  • 👍 Accepting PRs
• Suboptimal compilation for rest parameters #19182 Move rest arg array copy to first use
  • What exactly is first use?
    • At the top level before any block or statement which consumes it
    • Or the very top if it appears in a function body
  • There's a PR to not emit it if it's unused
  • If all uses are indexed/property access expressions, then we don't need to copy the array at all
  • Note that in non-strict mode, arguments is mutable
  • Optimize where we're sure it's safe
  • 👍 Accepting PRs
• Private Member Minification Design Proposal #16037 Minify private members
  • Listed code is totally broken
  • We don't know what names are safe from subclass overwrites
  • Could we emit a config file to feed into uglify?
  • Investigate offline
• Treat assignments to properties on functions as valid declarations #15868 Allow Salsa-style property assignment declarations on functions
  • No current solutions are good
  • Long discussion about where those statements could go vs should
  • You have to put some of your cake in the fridge and eat the rest
  • At least restrict this to the same containing function
  • 👍 for function declarations, function-expr-initialized consts, 👎 for classes
• Allow trailing commas in type parameter/argument lists #16152 Allow trailing commas in type parameter + argument lists
  • AMF
• Is it really truly wrong to have an empty array for files in the config? #12762 Allow empty file list in tsconfig
  • --allowNoFiles ? 😢
  • Out of time

[masaeedu]

Looks like #18896 was missed.