Improve formatting for filtering

[westy92]

You can filter CloudWatch logs, but only easily if they are formatted a certain way.

Currently, this is the formatting code:

return _.isEmpty(log.meta) ?
  [ log.level, log.msg ].join(' - ') :
  [ log.level, log.msg, stringify(log.meta) ].join(' - ');

However, according to Amazon, pieces must be space-delimited. It also states The characters between a pair of square brackets [] or two double quotes ("") are treated as a single field.

Would it be best to delimit pieces with spaces, wrapping most with [] or ""?

Example:

Current: level - multi word message - meta I believe Amazon sees this as the following pieces:

• level
• -
• multi
• word
• message
• -
• meta

I think if we instead wrapped pieces like this... level [multi word message] [meta] Amazon would see:

• level
• multi word message
• meta

If we want to do this, here is a rough patch:

var result = log.level + ' [' + log.msg + ']';
if (!_.isEmpty(log.meta)) result += ' [' + stringify(log.meta) + ']';
return result;

[lazywithclass]

Thanks @westy92 I am currently working on the other issues, but if you think it would help you and others feel free to submit a PR.