Assertions: Difference between revisions

=={{header|Wren}}==

Wren does not have assertions as such though we can write something similar.

<lang ecmascript>var assertEnabled = true

var assert = Fn.new { |cond|

if (assertEnabled && !cond) Fiber.abort("Assertion failure")

}

var x = 42

assert.call(x == 42) // fine

assertEnabled = false

assert.call(x > 42) // no error

assertEnabled = true

assert.call(x > 42) // error</lang>

{{out}}

<pre>

$ wren assertion.wren

Assertion failure

[./assertion line 4] in new(_) block argument

[./assertion line 12] in (script)

</pre>