需要帮助来“异步”一个 Function("...").call() for firestore

Question

各位大师，早安，

我构建了我的代码以允许来自用户的动态输入字符串（sCmd），然后该字符串将被推送到函数中

let res = Function("moment", '"use strict";' + sCmd).call(this, moment);

这是一个用户输入示例，允许他们调用“等待”命令

let sCmd = `
    // ---- cmd START
    function simulateFirebaseGet() {
      return new Promise(resolve => {
        setTimeout(() => {
          resolve('resolved from simulateFirebaseGet()');
        }, 2000);
      });
    }
    async function callAsyncFunc() {
      console.log('#2 - run callAsyncFunc()');

      let res = await simulateFirebaseGet();
      console.log('#3 - start wait 2 sec')
      console.log('#4 -', res);
      console.log('#5 - waited 2 sec')
    }

    console.log('#1 - START Function()');
     callAsyncFunc()
    console.log('#6 - STOP Function()');
    // ---- cmd END
    `;

但它并没有按照我的预期工作。控制台日志

#1 - START Function()
#2 - run callAsyncFunc()
#6 - STOP Function()
#3 - start wait 2 sec
#4 - resolved from simulateFirebaseGet()
#5 - waited 2 sec

我期待下面的东西

#1 - START Function()
#2 - run callAsyncFunc()
#3 - start wait 2 sec
#4 - resolved from simulateFirebaseGet()
#5 - waited 2 sec
#6 - STOP Function()

我还提供了StackBlitz link。如果我把“等待”放在

await callAsyncFunc()

我会收到错误Error: Unexpected identifier

更新： 在@CertainPerformance 回复后，我选择了第二种方法并按顺序运行。凉爽的！但很快我注意到一旦我将调用者更改为

console.log("START OUTSIDE Function()");
let res = Function("moment", '"use strict";' + sCmd).call(
  this,
  moment
); 
console.log("STOP OUTSIDE Function()");

控制台日志输出为

START OUTSIDE Function()
#1 - START Function()
run helper
#2 - run callAsyncFunc()
STOP OUTSIDE Function()
#3 - start wait 2 sec
#4 - resolved from simulateFirebaseGet()
#5 - waited 2 sec
#6 - STOP Function()

我需要它来运行

START OUTSIDE Function()
#1 - START Function()
run helper
#2 - run callAsyncFunc()
#3 - start wait 2 sec
#4 - resolved from simulateFirebaseGet()
#5 - waited 2 sec
#6 - STOP Function()
STOP OUTSIDE Function()

在我的用例中，我必须循环“Function(...).call()”并且它们需要按顺序处理。前面循环中的结果将用于“Function(...).call()”中后面的项中的计算。

Answer 1

要么在 callAsyncFn() 解析后将 #6 放入 .then 中，要么将整个函数放入 IIFE 以便您可以 await 调用 callAsyncFn：

let sCmd = `
    // ---- cmd START
    function simulateFirebaseGet() {
      return new Promise(resolve => {
        setTimeout(() => {
          resolve('resolved from simulateFirebaseGet()');
        }, 2000);
      });
    }
    async function callAsyncFunc() {
      console.log('#2 - run callAsyncFunc()');

      let res = await simulateFirebaseGet();
      console.log('#3 - start wait 2 sec')
      console.log('#4 -', res);
      console.log('#5 - waited 2 sec')
    }

    console.log('#1 - START Function()');
     callAsyncFunc().then(() => {
        console.log('#6 - STOP Function()');
        // ---- cmd END
    });
    `;
    let res = Function("moment", '"use strict";' + sCmd).call(this, {});

或

let sCmd = `
    // ---- cmd START
    (async () => {

      function simulateFirebaseGet() {
        return new Promise(resolve => {
          setTimeout(() => {
            resolve('resolved from simulateFirebaseGet()');
          }, 2000);
        });
      }
      async function callAsyncFunc() {
        console.log('#2 - run callAsyncFunc()');

        let res = await simulateFirebaseGet();
        console.log('#3 - start wait 2 sec')
        console.log('#4 -', res);
        console.log('#5 - waited 2 sec')
      }

      console.log('#1 - START Function()');
      await callAsyncFunc()
      console.log('#6 - STOP Function()');
      // ---- cmd END
  })();
    `;
    let res = Function("moment", '"use strict";' + sCmd).call(this, {});

你需要在外面做同样的事情——要么await调用构造函数，要么调用.then。

let sCmd = `
    // ---- cmd START
    function simulateFirebaseGet() {
      return new Promise(resolve => {
        setTimeout(() => {
          resolve('resolved from simulateFirebaseGet()');
        }, 2000);
      });
    }
    async function callAsyncFunc() {
      console.log('#2 - run callAsyncFunc()');

      let res = await simulateFirebaseGet();
      console.log('#3 - start wait 2 sec')
      console.log('#4 -', res);
      console.log('#5 - waited 2 sec')
    }

    console.log('#1 - START Function()');
    return callAsyncFunc().then(() => {
        console.log('#6 - STOP Function()');
        // ---- cmd END
    });
    `;
console.log("START OUTSIDE Function()");
Function("moment", '"use strict";' + sCmd).call(
  this,
  {}
)
  .then((res) => {
    console.log("STOP OUTSIDE Function()");
  });