'extends' is not compiling when used inside declaration file and importHelpers option is switched on

[Nipheris]

TypeScript Version: 2.1.4 / 2.2.0-dev.20161207

Code

interface Animal {
	type: string;
}

export declare class Pet implements Animal {
	public type: string;
	public name: string;
	constructor();
}

export declare class Dog extends Pet {
	public breed: string;
	constructor();
}

Expected behavior:
Compiles successfully.

Actual behavior:
Compilation fails with the following error:

error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.

The same source code compiles fine on TypeScript 2.1.1. Installed tslib package has version 1.2.0.

[mhegazy]

are you using --importHelpers?

[mhegazy]

never mind, saw the title :)

[mhegazy]

The error should not be shown in the .d.ts file, this a bug.

but if you have tslib installed you should not see the error anyways, is this correct?

[timocov]

Mohamed Hegazy (@mhegazy) yeah, this is correct

[PavelPZ]

I cannot run importHelpers with installed tslib.

TypeScript Version: 2.1.4 vith VS.NET

Code
export const o = { a: 1, name: "o" };
export const copy = { ...o };

tsconfig.json

{
 "compilerOptions": {
 "target": "es5",
 "module": "system",
 "importHelpers": true,
 "lib": [
 "dom",
 "es6"
 ],
 }
}

installation
I use both JSPM and NPM

jspm install tslib
npm install tslib --save

package.json

{
 "jspm": {
 "dependencies": {
 "tslib": "npm:tslib@^1.2.0",
 }
 "dependencies": {
 "tslib": "^1.2.0"
 }
}

[mhegazy]

pavelpz (@PavelPZ), the compiler uses the same module resolution strategy to resolve tslib as it does with any other module. so you will need to either 1. add "moduleResolution": "node", or 2. add a path mapping for it: "paths": { "tslib" : ["./node_modules/tslib/tslib.d.ts"] }

[PavelPZ]

Mohamed Hegazy (@mhegazy), thanks.

I am using JSPM, so I modified my tsconfig.json:

{
 "compilerOptions": {"baseUrl": ".",
 "paths": {
 "tslib": [ "jspm_packages/npm/tslib@1.2.0/tslib.d.ts" ]
 }, 

and compiler is now OK.

But there is a problem with runtime (Uncaught (in promise) Error: (SystemJS) tslib.__assign is not a function in Chrome).
tslib.js is correctly loaded, but its factory is never called.

jspm.config.js

SystemJS.config({
 paths: {
 "tslib": "jspm_packages/npm/tslib/tslib",

[mhegazy]

Fix for the original issue should be in tonight typescript@next.

[mhegazy]

pavelpz (@PavelPZ) i have not had time to look into the jspm issue yet. have you made progress past this issue, or are you still blocked on it?