### Installing DeAsync via npm

Source: https://github.com/abbr/deasync/blob/master/README.md

This snippet provides the command to install the `deasync` library using npm. It is a prerequisite for using the library in a Node.js project.

```Shell
npm install deasync
```

--------------------------------

### Using DeAsync's loopWhile for Custom Asynchronous APIs in JavaScript

Source: https://github.com/abbr/deasync/blob/master/README.md

This example illustrates how to use `deasync.loopWhile` to block execution until a specific condition is met, which is useful for asynchronous functions that do not follow the conventional `(error, result)` callback signature. It sets a `done` flag within the callback and uses `loopWhile` to pause execution until `done` becomes true, ensuring data is populated.

```JavaScript
var done = false;
var data;
asyncFunction(p1,function cb(res){
    data = res;
    done = true;
});
require('deasync').loopWhile(function(){return !done;});
// data is now populated
```

--------------------------------

### Wrapping Asynchronous Functions with DeAsync in JavaScript

Source: https://github.com/abbr/deasync/blob/master/README.md

This snippet demonstrates how to use `deasync` to wrap a standard Node.js asynchronous function (like `child_process.exec`) into a synchronous one. It shows how to call the wrapped function and handle potential errors using a `try-catch` block, ensuring that subsequent code execution waits for the asynchronous operation to complete.

```JavaScript
var deasync = require('deasync');
var cp = require('child_process');
var exec = deasync(cp.exec);
// output result of ls -la
try{
    console.log(exec('ls -la'));
}
catch(err){
    console.log(err);
}
// done is printed last, as supposed, with cp.exec wrapped in deasync; first without.
console.log('done');
```

--------------------------------

### Implementing Synchronous Delay with DeAsync's Sleep in JavaScript

Source: https://github.com/abbr/deasync/blob/master/README.md

This snippet demonstrates how to create a synchronous function that waits for an asynchronous operation (simulated by `setTimeout`) to complete using `deasync.sleep`. It continuously checks a condition (`ret === undefined`) and pauses execution for a short duration until the asynchronous callback populates the `ret` variable, effectively making the `setTimeout` behave synchronously.

```JavaScript
function SyncFunction(){
  var ret;
  setTimeout(function(){
      ret = "hello";
  },3000);
  while(ret === undefined) {
    require('deasync').sleep(100);
  }
  // returns hello with sleep; undefined without
  return ret;    
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.