This Sugar adds three commands in the Actions→Convert/Strip menu to convert all the linebreaks in the frontmost document to either Unix, Windows, or Mac-style linebreaks. There is also an action to make your linebreaks lonely (strip all non-linebreak whitespace from empty lines).
Requires Espresso 2.1
The easiest way to install ConvertLinebreaks.sugar is directly from GitHub:
cd ~/Library/Application\ Support/Espresso/Sugars git clone git://github.com/onecrayon/ConvertLinebreaks.sugar.git
Relaunch Espresso after installing the Sugar to gain access to its actions.
Copyright (c) 2011-2017 Ian Beck
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.