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Javascript 在Node.js上使用dynamic import()函数_Javascript_Node.js_Babeljs_Es6 Modules_Dynamic Import - Fatal编程技术网

Javascript 在Node.js上使用dynamic import()函数

Javascript 在Node.js上使用dynamic import()函数,javascript,node.js,babeljs,es6-modules,dynamic-import,Javascript,Node.js,Babeljs,Es6 Modules,Dynamic Import,我正在尝试在节点v10环境中实现的基本功能 main.js async function main() { try { const moduleA = await import('./moduleA'); console.log('Inside main function...'); moduleA(); console.log(moduleA); } catch(err) { console.log(err); } } main();

我正在尝试在节点v10环境中实现的基本功能

main.js

async function main() {
  try {
    const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

main();
console.log('Inside global scope module A...');

function moduleA() {
  console.log('Running module A function...');
}

export default moduleA;
let moduleA = null;
import('./moduleA').then((importedModule) => {
  moduleA = importedModule;
  main();
});

async function main() {
  try {
    // const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

// main();
moduleA.js

async function main() {
  try {
    const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

main();
console.log('Inside global scope module A...');

function moduleA() {
  console.log('Running module A function...');
}

export default moduleA;
let moduleA = null;
import('./moduleA').then((importedModule) => {
  moduleA = importedModule;
  main();
});

async function main() {
  try {
    // const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

// main();
这是我运行npx babel node main.js时得到的结果

PS C:\myProject\test-module-imports> npx babel-node src/main.js
Inside global scope module A...
Inside main function...
TypeError: moduleA is not a function
    at main (C:\myProject\test-module-imports\src/main.js:9:5)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
    at Object.<anonymous> (C:\myProject\test-module-imports\node_modules\@babel\node\lib\_babel-node.js:174:21)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)
import moduleA from './moduleA';

async function main() {
  try {
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

main();
我也试过这个(下面的代码)。结果是一样的:

main.js

async function main() {
  try {
    const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

main();
console.log('Inside global scope module A...');

function moduleA() {
  console.log('Running module A function...');
}

export default moduleA;
let moduleA = null;
import('./moduleA').then((importedModule) => {
  moduleA = importedModule;
  main();
});

async function main() {
  try {
    // const moduleA = await import('./moduleA');
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

// main();
问题

我做错了什么


这工作正常(常规导入): 也使用npx babel节点src/main.js执行

PS C:\myProject\test-module-imports> npx babel-node src/main.js
Inside global scope module A...
Inside main function...
TypeError: moduleA is not a function
    at main (C:\myProject\test-module-imports\src/main.js:9:5)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
    at Object.<anonymous> (C:\myProject\test-module-imports\node_modules\@babel\node\lib\_babel-node.js:174:21)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)
import moduleA from './moduleA';

async function main() {
  try {
    console.log('Inside main function...');
    moduleA();
    console.log(moduleA);
  }
  catch(err) {
    console.log(err);
  }
}

main();
package.json(额外信息)

加载模块并返回包含其所有导出的模块对象。要访问默认导出,请使用模块对象的
default
属性:

const moduleA = await import('./moduleA');
moduleA.default();

// OR

const { default: moduleA } = await import('./moduleA');
moduleA();

就这样!非常感谢。这是一个在大多数帖子中都没有提到的非常重要的细节。谢谢:)救生员?没有,但是非常接近