about tree-shaking

[wdssmq]

// base.js
const str1 = "1111";

const str2 = "2222".trim();

const str3 = `3333`;

const str4 = `4444`.trim();

const $ = window.$ || unsafeWindow.$;

export { str1, str2, str3, str4, $ };

// main.js
import { str1, str2, str3, str4, $ } from "./base";

console.log(str1);

bundle：

(function () {
	'use strict';

	// base.js
	const str1 = "1111";

`4444`	.trim();

	window.$ || unsafeWindow.$;

	// main.js

	console.log(str1);

})();

如何不输出「4444 .trim();」和 window.$ || unsafeWindow.$;两行？

How to not output 「4444 .trim();」and window.$ || unsafeWindow.$;?

[dnalborczyk]

@wdssmq are you using an old version of rollup?

https://rollupjs.org/repl/?version=2.72.0&shareable=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

[dnalborczyk]

nm, your question is probably related to:

https://rollupjs.org/repl/?version=2.72.0&shareable=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

[dnalborczyk]

I'll let others chime in, but this const str4 = `4444`.trim(); appears to be a bug, or a feature request.

the second const $ = window.$ || unsafeWindow.$; looks correct as window.$ and the global unsafeWindow.$ could have potential side effects.

that said, I think I still see a bug, unless it's by design:

I believe this alone should not be tree-shaken: const $ = window.$, as a $ getter could have side effects.

https://rollupjs.org/repl/?version=2.72.0&shareable=JTdCJTIybW9kdWxlcyUyMiUzQSU1QiU3QiUyMm5hbWUlMjIlM0ElMjJtYWluLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMmNvbnN0JTIwJTI0JTIwJTNEJTIwd2luZG93LiUyNCUyMiUyQyUyMmlzRW50cnklMjIlM0F0cnVlJTdEJTVEJTJDJTIyb3B0aW9ucyUyMiUzQSU3QiUyMmZvcm1hdCUyMiUzQSUyMmVzJTIyJTJDJTIybmFtZSUyMiUzQSUyMm15QnVuZGxlJTIyJTJDJTIyYW1kJTIyJTNBJTdCJTIyaWQlMjIlM0ElMjIlMjIlN0QlMkMlMjJnbG9iYWxzJTIyJTNBJTdCJTdEJTdEJTJDJTIyZXhhbXBsZSUyMiUzQW51bGwlN0Q=

[wdssmq]

@dnalborczyk
Thanks for the reply.

Some of the older monkey scripts use jQuery, which I will gradually replace with native js, or comment out.

The other issue does look like a bug, and may need further confirmation.

[lukastaegert]

As for the window question, Rollup does not know the $ global and more importantly does not know the unsafeWindow global. Accessing a non-existing global will throw an error, so Rollup needs to keep the code. Setting treeshake.unknownGlobalSideEffects to false will probably fix this, but maybe you also need treeshake.propertyReadSideEffects, see https://rollupjs.org/guide/en/#treeshake.

As for retaining .trim(), this will be fixed by #4511