typescript 为什么任何导入都修复了 --isolatedModules 错误？
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Why is --isolatedModules error fixed by any import?
提问by Svish
In a create-react-app typescript project, I tried to write this just to test some stuff quickly:
在 create-react-app 打字稿项目中，我试图写这个只是为了快速测试一些东西：
// experiment.test.ts
it('experiment', () => {
console.log('test');
});
But it gives me the following error, with a red squiggly beneath it:
但它给了我以下错误，下面有一个红色的波浪线it：
All files must be modules when the '--isolatedModules' flag is provided.
提供“--isolatedModules”标志时，所有文件都必须是模块。
However, if I change the file to the following, then everything apparently is fine (except for the unused import of course):
但是，如果我将文件更改为以下内容，那么一切显然都很好（当然，未使用的导入除外）：
// experiment.test.ts
import { Component} from 'react'; // literally anything, don't even have to use it
it('test', () => {
console.log('test');
});
Why? What is happening here? What does --isolatedModulesactually mean/do?
为什么？这里发生了什么？--isolatedModules实际上是什么意思/做什么？
回答by Titian Cernicova-Dragomir
Typescript treats files without import/exports as legacy script files. As such files are not modules and any definitions they have get merged in the global namespace. isolatedModulesforbids such files.
Typescript 将没有导入/导出的文件视为遗留脚本文件。由于这些文件不是模块，它们的任何定义都已合并到全局命名空间中。isolatedModules禁止此类文件。
Adding any import or export to a file makes it a module and the error disappears.
向文件添加任何导入或导出使其成为模块并且错误消失。
Also export {}is a handy way to make a file a module without importing anything.
也是export {}一种在不导入任何内容的情况下使文件成为模块的便捷方法。
