ReferenceError: _this is not defined, if an arrow function is a static member of a class.

[laszlopandy]

TypeScript Version: 2.4.0 / 2.4.1 / 2.5.0-dev.20170629

Code

/* TsBug.ts */
class Test {
    static member = async (x: string) => { };
}
Test.member("");

Compiled with: tsc TsBug.ts --lib es2015.promise,es5
Run with: node TsBug.js

Expected behavior:
No output.

Actual behavior:

/..<snip>../TsBug.js:39
    Test.member = function (x) { return __awaiter(_this, void 0, void 0, function () { return __generator(this, function (_a) {
                                                  ^

ReferenceError: _this is not defined
    at Function.Test.member (/..<snip>../TsBug.js:39:51)

[ikatyang]

Something wrong between v2.3.4 and v2.4.0

[jwbay]

Ref: #16120