Microsoft/TypeScript

Code generated for optional call could be optimized when the result is unused

Open

#38.835 aberto em 28 de mai. de 2020

Ver no GitHub
 (3 comments) (0 reactions) (0 assignees)TypeScript (6.726 forks)batch import
Effort: ModerateExperience EnhancementHelp WantedSuggestion

Métricas do repositório

Stars
 (48.455 stars)
Métricas de merge de PR
 (Mesclagem média 2d 7h) (8 fundiu PRs em 30d)

Description

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.

Guia do colaborador