<!DOCTYPE qhelp PUBLIC

"-//Semmle//qhelp//EN"

"qhelp.dtd">

<qhelp>

<overview>

<p>

Since JavaScript is a dynamically typed language, module imports in node.js are not statically checked

for correctness: calls to <code>require</code> simply return an object containing all the exports of

the imported module, and accessing a member that was not, in fact, exported, yields

<code>undefined</code>. This is most likely unintentional and usually indicates a bug.

</p>

</overview>

<recommendation>

<p>

Examine the import in question and determine the correct name of the symbol to import.

</p>

</recommendation>

<example>

<p>

In the following example, module <code>point.js</code> exports the function <code>Point</code> by

assigning it to <code>module.exports</code>. The client module <code>client.js</code> tries to

import it by reading from the <code>Point</code> property, but since this property does not exist

the result will be <code>undefined</code>, and the <code>new</code> invocation will fail.

</p>

<sample src="examples/DubiousImport.js" />

<p>

Instead of reading the <code>Point</code> property, <code>client.js</code> should directly use

the result of the <code>require</code> call:

</p>

<sample src="examples/DubiousImportGood.js" />

</example>

<references>

<li>Node.js Manual: <a href="http://nodejs.org/api/modules.html">Modules</a>.</li>

</references>

</qhelp>