Microsoft/TypeScript
在 GitHub 查看No compile error thrown when `this` referenced before call to `super` completes
Open
#8,060 创建于 2016年4月13日
Effort: DifficultHelp WantedSuggestion
描述
TypeScript Version:
1.8.9
Code JSFiddle: https://jsfiddle.net/kitsonk/fs9t96ep/ TS Playground: http://goo.gl/X7cgvV
class A {
constructor(fn: () => void) {
fn.call(this);
}
foo: string = 'foo';
}
class B extends A {
constructor() {
super(() => {
console.log(this);
});
}
bar: string = 'bar';
}
const b = new B();
Expected behavior:
Typescript should guard against the use of this as the call to super has not completed. Thus it should not compile.
Actual behavior:
Typescript compiles this successfully. It works fine when the target is set to es5 but breaks the browser when target is set to es6.
Error is: VM89:55 Uncaught ReferenceError: this is not defined