Logging¶
CasperJS allows logging using the casper.log() method and these standard event levels:
debug
info
warning
error
Sample use:
var casper = require('casper').create();
casper.log('plop', 'debug');
casper.log('plip', 'warning');
Now, there are two things to distinguish: log storage and log display; by default CasperJS won’t print the logs to the standard output. In order to do so, you must enable the verbose
Casper option:
var casper = require('casper').create({
verbose: true
});
Also, by default Casper is configured to filter logging which is under the error
level; you can override this setting by configuring the logLevel
option:
var casper = require('casper').create({
verbose: true,
logLevel: 'debug'
});
You can also dump a JSON log of your Casper suite just by rendering the contents of the Casper.result.log
property:
var casper = require('casper').create({
// ...
casper.run(function() {
require('utils').dump(this.result.log);
this.exit();
});
Last, if you print log messages to the standard output using the verbose
option, you’ll get some fancy colors:
var casper = require('casper').create({
verbose: true,
logLevel: 'debug'
})
casper.log('this is a debug message', 'debug');
casper.log('and an informative one', 'info');
casper.log('and a warning', 'warning');
casper.log('and an error', 'error');
casper.exit();
This will give the following output:
Hint
CasperJS doesn’t write logs on the filesystem. You have to implement this by yourself if needed.