UnwrapParagraphs.js

/**
	{
		"api":1,
		"name":"Unwrap Paragraphs",
		"description":"Joins soft-wrapped lines into single lines, keeping paragraph breaks.",
		"author":"felix",
		"icon":"collapse",
		"tags":"unwrap,join,lines,paragraph,reflow,wrap"
	}
**/

function main(input) {
	input.text = input.text
		.replace(/\r\n?/g, '\n')
		.split(/\n[ \t]*\n+/)
		.map(p => p.replace(/[ \t]*\n[ \t]*/g, ' ').trim())
		.filter(p => p.length > 0)
		.join('\n\n');
}