Description
🔎 Search Terms
"shadowed", "shadowed variable", "generator"
🕗 Version & Regression Information
- This changed in commit or PR Move complex parameter lists of async function into downlevel generator body #56296
⏯ Playground Link
💻 Code
class X {
public static a = async (someVar: boolean = true) => {
return await X.b();
};
public static b = async () => {
return "GOOD";
};
}
declare class process {
static exit(code: number): never;
}
X.a()
.then(console.log)
.catch(() => {
console.error("BAD");
process.exit(1);
});🙁 Actual behavior
Between TS v5.4.2 and TS v5.3.3, the generated code from the above code sample changes to shadow the _a variable in the outer closure. See diff below:
var X = /** @class */ (function () {
function X() {
}
var _a;
_a = X;
- X.a = function (someVar) {
- if (someVar === void 0) { someVar = true; }
- return __awaiter(_a, void 0, void 0, function () {
- return __generator(_a, function (_b) {
- switch (_b.label) {
+ X.a = function () {
+ var args_1 = [];
+ for (var _i = 0; _i < arguments.length; _i++) {
+ args_1[_i] = arguments[_i];
+ }
+ return __awaiter(_a, __spreadArray([], args_1, true), void 0, function (someVar) {
+ if (someVar === void 0) { someVar = true; }
+ return __generator(_a, function (_a) {
+ switch (_a.label) {
case 0: return [4 /*yield*/, _a.b()];
- case 1: return [2 /*return*/, _b.sent()];
+ case 1: return [2 /*return*/, _a.sent()];
}
});
});
};
X.b = function () { return __awaiter(_a, void 0, void 0, function () {
return __generator(_a, function (_b) {
return [2 /*return*/, "GOOD"];
});
}); };
return X;
}());
X.a()
.then(console.log)
.catch(function () {
console.error("BAD");
process.exit(1);
});
Note that helpers have been omitted from this code sample.
Notice that in the context of the function, the class/function X is assigned to a variable _a in the "ambient" context of the class. In TS v5.3.3, the async state machine's state variable is declared as _b, but in TS v.5.4.2 is appears as if the context is lost when the state machine is generated, so the state is declared as _a, shadowing the earlier-declared _a.
🙂 Expected behavior
Expected that the async state machine's state variable does not shadow another variable.
Additional information about the issue
No response
This issue was found by @ipip2005.