如何使用 async / await 在量角器中等待状态

Question

我正在量角器中切换我的打字稿代码以使用 async / await 并且我有一个 verifyRow 方法，如果没有 .then 承诺，我似乎无法工作

尝试在 browser.wait 中使用 await 并尝试在 browser.wait 中添加新的 Promise，它调用 asycn 方法

findRowByMultipleCellText 被定义为一个异步方法，它返回一个数字（即 rowIndex）

    async verifyRow(columns: string[], values: string[], shouldFind = true, timeout = 60, refresh = false) {
    let results: boolean = false;

    const columnValueString: string = this.generateColumnValuesPrintString(columns, values);

    // Wait for the row to exist based on shouldFind
    // let rowIndex: number;

    await this.driver.wait(() => {
      return new Promise(resolve => {
      this.findRowByMultipleCellText(columns, values).then((rowIndex: number) => {
      if (rowIndex >= 0 && shouldFind === true) {
        results = true;
        logger.debug('Row EXISTS in the grid: \n' + columnValueString);
      } else if (rowIndex <= -1 && shouldFind === false) {
        results = true;
        logger.debug("Row DOESN'T exist in the grid: \n" + columnValueString);
      } else {
        if (refresh === true) {
          logger.info('Refreshing the vsphere web client main page');
          new VClientMainPage().refreshButton.click();
        }
      }
    });

    resolve(results);
  });


  //  return results;
  }, timeout * 1000);

  if (results === false) {
    if (shouldFind === true) {
      throw new Error("Row DOESN'T exist in the grid: \n" + columnValueString);
    } else {
      throw new Error('Row EXIST in the grid: \n' + columnValueString);
    }
    }
  }

我也试过这个，但是await this.find 中存在错误，因为await 只能在异步函数中调用

await this.driver.wait(() => {
  let rowIndex: number = await this.findRowByMultipleCellText(columns, values);
    if (rowIndex >= 0 && shouldFind === true) {
      results = true;
      logger.debug('Row EXISTS in the grid: \n' + columnValueString);
    } else if (rowIndex <= -1 && shouldFind === false) {
      results = true;
      logger.debug("Row DOESN'T exist in the grid: \n" + columnValueString);
    } else {
      if (refresh === true) {
        logger.info('Refreshing the vsphere web client main page');
        new VClientMainPage().refreshButton.click();
      }
    }
}, timeout * 1000);

if (results === false) {
  if (shouldFind === true) {
    throw new Error("Row DOESN'T exist in the grid: \n" + columnValueString);
  } else {
    throw new Error('Row EXIST in the grid: \n' + columnValueString);
  }
}

如果我在等待循环之外调用它，我需要 findRowByMultipleCellTest 返回一个数字。如果它 >= 0，我们会跳出循环。

发生的事情是，当我在 new Promise 中有代码时，它会调用 this.find，但它永远不会到达返回值的地步.. 几乎就像代码被推到堆栈的末尾一样，所以我永远不会中断出去

Answer 1

选项 1) 在browser.wait() 中使用Promise，您应该在promise.then() 内部而不是在其外部调用resolve(results)。

async verifyRow(columns: string[], values: string[], shouldFind = true, timeout = 60, refresh = false) {
    let results: boolean = false;

    const columnValueString: string = this.generateColumnValuesPrintString(columns, values);

    // Wait for the row to exist based on shouldFind
    // let rowIndex: number;
    await this.driver.wait(() => {

        return new Promise(resolve => {
            this.findRowByMultipleCellText(columns, values).then((rowIndex: number) => {
                if (rowIndex >= 0 && shouldFind === true) {
                    results = true;
                    logger.debug('Row EXISTS in the grid: \n' + columnValueString);
                } else if (rowIndex <= -1 && shouldFind === false) {
                    results = true;
                    logger.debug("Row DOESN'T exist in the grid: \n" + columnValueString);
                } else {
                    if (refresh === true) {
                        logger.info('Refreshing the vsphere web client main page');
                        new VClientMainPage().refreshButton.click();
                    }
                }

                resolve(results);
                // you should call resolve(..) inside then(),
                // otherwise resolve() is executed prior to 
                // the completion of findRowByMultipleCellText()'s async execution.
            });


        });


        //  return results;
    }, timeout * 1000);

    if (results === false) {
        if (shouldFind === true) {
            throw new Error("Row DOESN'T exist in the grid: \n" + columnValueString);
        } else {
            throw new Error('Row EXIST in the grid: \n' + columnValueString);
        }
    }
}

选项 2) 仅使用 async/await 启用代码简洁。

async verifyRow(columns: string[], values: string[], shouldFind = true, timeout = 60, refresh = false) {
    let results: boolean = false;

    const columnValueString: string = this.generateColumnValuesPrintString(columns, values);

    // Wait for the row to exist based on shouldFind
    // let rowIndex: number;
    await this.driver.wait(() => {

        await rowIndex: number = this.findRowByMultipleCellText(columns, values);

        if (rowIndex >= 0 && shouldFind === true) {
            results = true;
            logger.debug('Row EXISTS in the grid: \n' + columnValueString);
        } else if (rowIndex <= -1 && shouldFind === false) {
            results = true;
            logger.debug("Row DOESN'T exist in the grid: \n" + columnValueString);
        } else {
            if (refresh === true) {
                logger.info('Refreshing the vsphere web client main page');
                await new VClientMainPage().refreshButton.click();

                // Add await ahead of above click() too.
            }
        }
        return results;

     }, timeout * 1000);

    if (results === false) {
        if (shouldFind === true) {
            throw new Error("Row DOESN'T exist in the grid: \n" + columnValueString);
        } else {
            throw new Error('Row EXIST in the grid: \n' + columnValueString);
        }
    }
}