Suggestion Backlog Slog, 9/26/2016

[RyanCavanaugh]

• Handling input file extensions other than .ts, .js, .tsx, and .jsx #10939 Other file extensions
  • Simple implementation
  • Is completely divorcing the file kind from its extension actually a good idea?
  • Affects module resolution, of course
  • 👍 for 'preserve-js'
  • 👎 overall
• tsc CLI: allow boolean options to have explicit false value #10967 Explicit false values on commandline
  • 👍
• Add "related spans" to diagnostic messages #10489 Related spans in diagnostic messages
  • More examples of how this would be useful
  • How would this be handled in the commandline?
• Add compiler option to parse in strict mode #10758 Option to parse in strict mode
  • Problem: Our services file had a strict-mode reserved identifier, which we didn't catch
  • Add a flag to parse all files in strict mode
  • 👍
  • --alwaysStrict, also emits "use strict"; in files which require it
  • Accepting PRs
• Ability to skip elements in tuple type annotation #2671 Ability to skip elements in tuple type annotation
  • Useful for destructuring
  • 👎
• Suggestion: use :{type} to omit formal parameter when declare function interface or something else #10984 Skip parameter names in positions
  • Just use a, b, c, d, e ?
  • Unclear from inspection what this really does
  • 👎
• Interactive init #10964 Interactive init
  • Everyone in the room hates npm's interactive init
  • Putting more things with comments in tsconfig.json would be better
  • Asking people questions they don't understand is a big turn-off
  • 👎
• strictNullChecks mode - variable initial value is ignored in the control flow #10640 Initializer not tracked in strictNullChecks
  • Treat this as if it were a set of following property assignments?
  • Performance problem if we treat all types a union of themselves and their un-undefined counterparts
  • It is weird this doen't behave the same as its expanded counterpart
  • Design limitation
  • Will think about some more
• Optimize tsc --w using the CoS builder #10879 Make 'watch' use new faster compile-on-save code
  • Move code from server to tsc that can do this correctly for isolated modules
  • 👍
• unknown: less-permissive alternative to any #10715 unknown type
  • What's the difference between this and {} | null | undefined ?
  • What's the intended semantics?
  • What's an error here but not for any?
  • Why is it legal to pass this to Array.isArray... but not Array#concat, presumably?
  • A type that expands through type guards and property access
  • Should this just be what we do with any?
  • Could be represented with the mix of known properties and any's behavior
    • Except also not assignable to anything
  • Revisit
• Do not emit files with no statments #10908 Emit with no-statement file in AMD and outfile
  • Not safe when file goes from 1 -> 0 statements
  • Just rename to .d.ts
  • 👎
• --strictNullChecks does not gaurd against optional arguments assignment #9450 strictNullChecks does not guard against optional arguments
  • Unrelated to parameter bivariance
  • Burdened by bad definition files written when we didn't enforce this correctly
  • Revisit
• Covariance / Contravariance Annotations #1394 Co/contra-variance annotations
  • Coming up for Promises more
  • Should look into this
• Support Custom JSX Pragma #9582 Custom JSX factory
  • jsxFactory: sure
  • Accepting PRs