ecma-async-loop

JavaScript / TypeScript library to help to perform asynchronous loop

javescripeto de assinchrono

The problem and the solution

You have a async function and need to loop it, but the loop structure in ecmascript do not allow you to use "await" keywork inside a loop (you are allowed, but it does not work)

async function yourCustomAsyncFunction(): Promise<void> {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve();
    }, 100);
  });
}

it does not work:

let index = 0;
while (index < 10) {
  await yourCustomAsyncFunction();
}

But you can do that:

asyncDoWhile({
  while: () => index < 10,
  execute: () => yourCustomAsyncFunction()
}).then(() => {
  //  loop complete
}).catch(e => {
  //  some of the functions has broken
});

//  you can create an execution queue to use in the for each method:
declare someHttpApi(importantData: number): Promise<void>;
const dataToSendToSomeApi = [ 2, 4, 2, 2, 6 ];

//  here you create an array of async functions (or functions that returns promises)
const executionQueue = dataToSendToSomeApi.map(no => {
  return () => someHttpApi(importantData);
});

asyncForEach(executionQueue).then(() => {
  //  loop complete
}).catch(e => {
  //  some of the functions has broken
});

Instalation

npm install ecma-async-loop --save

Contributing

1. Create an issue

No one feature will be implemented without it having an open issue and without which the proposed has been accepted by the team responsible for the project. After the issue is approved, the applicant, a team member or anyone else can open a pull request associated with that issue (just paste the issue link in the pull request).

2. Did you find a bug?

When logging a bug, please be sure to include the following:

• The library version;
• If at all possible, an isolated way to reproduce the behavior;
• The behavior you expect to see, and the actual behavior.

You can try to update the library to the last version to see if the bug has already been fixed.

3. Do not create a duplicate issue

Search the existing issues before logging a new one.

Some search tips:

• Don't restrict your search to only open issues. An issue with a title similar to yours may have been closed as a duplicate of one with a less-findable title.
• Check for synonyms. For example, if your bug involves an interface, it likely also occurs with type aliases or classes.

4. Create a Pull Request

Follow the steps:

• Create a fork from our repository by clicking here, install node, do a git clone of your forked repository and run npm install in the application folder;
• Create a branch in your forked repository, then code the feature or fix the bug;
• Run npm run lint, npm run test and npm run build in the repository;
• Create a Pull Request from your repository to this one, with the issue in the body and some information you think could be usefull to the reviewer (print or a gif of it working will be appreciated);
• The reviewer can ask some changes, don't be mad, this is the GIT Flow process;
• You get approved and your branch with the feature / fix