transform-class-properties: Static arrow functions are bound to undefined rather than the class #5222
Description
When using babel-plugin-transform-class-properties, it turns out that extending the https://babeljs.io/docs/plugins/transform-class-properties/ example to include a "boundStaticFunction" fails:
class Bork {
static staticProperty = "babeliscool";
static staticFunction = function() {
return Bork.staticProperty;
}
static boundStaticFunction = () => {
return this.staticProperty
}
}
//Static function exists on the class.
console.log(Bork.staticFunction()); // > "babelIsCool"
// BUG: static functions cannot be bound to class!
let fn = Bork.boundStaticFunction
console.log(fn())
Expected behavior
Calling (Bork.boundStaticFunction)() should behave the same way as Bork.boundStaticFunction().
Babel would emit code either like
Bork.boundStaticFunction = function () {
return this.staticProperty;
}.bind(Bork);
or:
Bork.boundStaticFunction = function () {
return Bork.staticProperty;
}
Actual results
Calling (Bork.boundStaticFunction)() results in an error:
Cannot read property 'staticProperty' of undefined
Babel has output this code (literally):
Bork.boundStaticFunction = function () {
return undefined.staticProperty;
};
Related behavior
Binding an instance property in a similar fashion does work as desired.