[SOLVED] gulp-typescript compiler throws errors on readonly modifier

gulp-typescript compiler throws errors on readonly modifier

I've just upgraded my app to use Angular 2 rc.6 and Angular Material 2 alpha 8-1. These packages rely on typescript 2 and the latter makes use of the new readonly modifier.

I use gulp-typescript to compile my .ts files and I'm now getting a lot of errors from files that use the readonly modifier. For instance, this line:

readonly change: Observable<MdButtonToggleChange>;

Throws these errors during compilation:

error TS1005: '=' expected.

error TS1005: ';' expected.

error TS1005: '(' expected.

I think this is probably because gulp-typescript internally uses typescript 1.8.10, which does not have the readonly modifier.

None of my own code uses readonly; The only files throwing errors are third-party typescript definition files (.d.ts) from Angular 2 Material packages. The files in question are all within my nodes_module/ folder, and I've tried to ignore them by having the following in tsconfig.json:

"exclude": [
  "node_modules",
  "typings"
]

The errors still show up though.

Can I solve this?
If not, is there an easy way to get the compiler to ignore .d.ts files?

Solution

One solution would be to add a TypeScript 2.0.2 RC dependency to your project (npm install typescript@rc --save-dev) and to pass it to gulp-typescript using the unofficial typescript option:

[...].pipe(ts({
    typescript: require('typescript')
}));