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<qhelp>

<overview>

<p>

The built-in <code>recover</code> function is only useful inside deferred

functions. Calling it in a function that is never deferred means that it will

always return <code>nil</code> and it will never regain control of a panicking

goroutine. The same is true of calling <code>recover</code> directly in a defer

statement.

</p>

</overview>

<recommendation>

<p>

Carefully inspect the code to determine whether it is a mistake that should be

fixed.

</p>

</recommendation>

<example>

<p>

In the example below, the function <code>fun1</code> is intended to recover

from the panic. However, the function that is deferred calls another function,

which then calls <code>recover</code>:

</p>

<sample src="RedundantRecover1.go" />

<p>

This problem can be fixed by deferring the call to the function which calls

<code>recover</code>:

</p>

<sample src="RedundantRecover1Good.go" />

<p>

In the following example, <code>recover</code> is called directly in a defer

statement, which has no effect, so the panic is not caught.

</p>

<sample src="RedundantRecover2.go" />

<p>

We can fix this by instead deferring an anonymous function which calls

<code>recover</code>.

</p>

<sample src="RedundantRecover2Good.go" />

</example>

<references>

<li>

<a href="https://blog.golang.org/defer-panic-and-recover">Defer, Panic, and Recover - The Go Blog</a>.

</li>

</references>

</qhelp>