JS Interop 1.0 issues

[jacob314]

Cases where Dartium doesn’t quite match Dart2JS behavior due to possibly hard to fix edge cases in facade Dartium has to maintain that Dart List is a JS Array, etc.

• js-interop:Array serialisation discrepancy between Dart interop and pure javascript #26768 JSON.stringify doesn’t return the right thing for Dart Lists
• JS interop corrupt DOM element if is used as argument in dart 1.14 and above (cross frame access issue) #25871 Bug on cross frame access.
• this value differs between dart2js and Dartium when calling a JS function. #25658 This sometimes not bound in Dartium when it is in dart2js. Might be fixed.
• [JS interop] "window." doesn't work in Dartium #24817 window. doesn't work as expected in Dartium. Hopefully small bug to fix.

Dart2JS bugs

• Support call method on @js classes without it upsetting dart2js js interop works, but analyzer doesn't like it #25321
• Type-checking of JS class interferes with subsequent type-checks  #25419 Type inference comes to the wrong conclusions after is checks on JS interop types. @johnniwinther

Missing Dartium functionality.

• Dartium JS interop patch doesn't escape dollar signs in identifiers #26718 properly escape all $ in property names passed to dartium to avoid bugs due to escaping and $.
• Dartium throws an internal error when when class with @JS annotation is private #25038 @js on a _Private class in Dartium (simple fix)

Bad error messages.

• MiniJsParser fails to compile []= operator #25053 Attempting to define an [] operator
  Attempting to extend a @js class
• fix js-interop tearoffs and optional arguments #25759 Specifying default values for optional arguments should not be allowed.
  [General Analyzer] better message when using a ctor annotation without parens

Feature work

• Provide a tool to generate JS-interop facades from TypeScript ts.d files #24874 codegen from d.ts files
• Support requiring modules via JS module systems #25059 Support JS module import.
• Expose expose js_util helper library.

Issues potentially gated on Dart 2.0

• Allow @JS on class method #24779 Issues solved if we had extension methods.
• Support rest params in package:js #24623 support rest and varargs
  Issues solved if we didn’t use _ for privates or changed conventions for underscores in named parameters.
• extend js class with js class with the new interop #25375 Extend JS class from Dart. Really gated on removing dartium dependency not so much Dart 2.0.

Exporting Dart classes to JS

We need a general high level design as well. This is simple to implement in DDC, harder in Dart2JS and painful in Dartium.

• exporting to JS might need some name mangling #24886 Support DART$ as well as JS$ to mangle Dart names.

Performance Improvements

• Faster resolution of interceptors for @JS() classes #26247 Caching interceptors for JS object classes (sra)

Issues not specific to new interop

• js-interop 0.6: getInterceptor(receiver). Returns invalid(NativeTypedData) interceptor for js object. #25785 General issue with Dart2JS determining interceptors for DOM classes based on class name (@sra).