Microsoft/TypeScript
Vedi su GitHubCode generated for optional call could be optimized when the result is unused
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#38.835 aperta il 28 mag 2020
Effort: ModerateExperience EnhancementHelp WantedSuggestion
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Descrizione
The generated code for optional chaining is a little verbose when the "return" value of the expression is not being used. For example, when simply calling a function:
maybe.close?.()
Here is a more complete example.
The second example generates:
(_c = (_b = perhaps.maybe) === null || _b === void 0 ? void 0 : _b.close) === null || _c === void 0 ? void 0 : _c.call(_b);
But could be optimized to:
(_b = perhaps.maybe) !== null && _b !== void 0 && (_c = _b.close) !== null && _c !== void 0 && _c.call(_b);
It's not a huge difference, but it saves 8 characters for each link in the chain.
While the spec says something like: "the expression short-circuits with a return value of undefined", when the return value is meaningless, then only the "short-circuit" part is important.