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POCoffeescript with callbacks & simplified error handling
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  1. POCoffeescript with callbacks & simplified error handling
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    copied!<p>I would like to be able to refactor the error handling from this coffeescript code:</p> <pre class="lang-coffee prettyprint-override"><code># Do some stuff with 2 levels of asynchronous callbacks and error handling vote = (res, data) -&gt; Case.findOne { caseId: data.id }, (err, mycase) -&gt; if err console.error 'Vote failed' else myvote = new Vote case: mycase._id myvote.save (err) -&gt; if err console.error 'Could not add vote' else console.log 'Success!' </code></pre> <p>to something like this:</p> <pre class="lang-coffee prettyprint-override"><code># Run my function, do error handling, and run the callback if no error runit = (func, arg, errmsg, callback) -&gt; func arg, (err, docs) -&gt; if err console.log errmsg + ': ' + err else callback docs # Original code, simplified vote = (res, data) -&gt; runit Case.findOne { caseId: data.id }, 'Vote failed', (mycase) -&gt; myvote = new Vote case: mycase._id runit myvote.save, 'Could not add vote', () -&gt; console.log 'Success!' </code></pre> <p>Obviously, the <code>runit</code> function needs be able to handle one or more arguments correctly, which I didn't attempt to code correctly.</p> <p>If I run it like this, I get an error:</p> <pre><code>node.js:201 throw e; // process.nextTick error, or 'error' event on first tick ^ TypeError: Cannot read property 'findOne' of undefined at /tmp/node_modules/mongoose/node_modules/hooks/hooks.js:27:28 at /tmp/lib/api.js:227:12 at Promise.&lt;anonymous&gt; (/tmp/lib/api.js:216:16) at Promise.&lt;anonymous&gt; (/tmp/node_modules/mongoose/lib/promise.js:120:8) at Promise.&lt;anonymous&gt; (events.js:67:17) at Promise.emit (/tmp/node_modules/mongoose/lib/promise.js:59:38) at Promise.complete (/tmp/node_modules/mongoose/lib/promise.js:70:20) at /tmp/node_modules/mongoose/lib/query.js:885:15 at model.&lt;anonymous&gt; (/tmp/node_modules/mongoose/lib/document.js:181:5) at model.init (/tmp/node_modules/mongoose/lib/model.js:181:36) </code></pre>
 

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