index.js

module.exports = {
	preCodeGen: function(ast, options) {
		ast.nodes = processNodes(ast.nodes)
		return ast
	}
}

function processNodes(nodes, insideConditional = false)
{
	for (let i = 0; i<nodes.length; i++)
	{
		const node = nodes[i]

		if(!/Each|Conditional/.test(node.type))
		{
			if(node.block)
				node.block.nodes = processNodes(node.block.nodes)

			if(node.type == 'Code' && node.buffer && node.mustEscape)
			{
				node.type = 'Text'
				node.val = `{{${node.val}}}`
				delete node.buffer
				delete node.mustEscape
				delete node.isInline
			}
			continue
		}

		if(node.consequent) // if this node is a conditional
		{
			const newNodes = [],
				consequent = processNodes(node.consequent.nodes),
				name = insideConditional? 'v-else-if' : 'v-if',
				vueIfAttr = [{ name, val: `"${node.test}"`, mustEscape: false }]

			newNodes.push(
				processControlNode(consequent, vueIfAttr, `empty ${name}=${node.test}`)
			)

			if(node.alternate)
			{
				if(node.alternate.type == 'Block')
				{
					const alternate = processNodes(node.alternate.nodes),
						vueElseAttr = [{ name: 'v-else', val: true, mustEscape: false }]
					newNodes.push(
						processControlNode(alternate, vueElseAttr, `empty v-else`)
					)
				}
				else
					newNodes.push( ...processNodes([node.alternate], true))
			}
			
			nodes.splice(i, 1, ...newNodes)
			i += newNodes.length-1
		}
		else // its a loop
		{
			const loop = (node.key ? `"(${node.val}, ${node.key})` : `"${node.val}` )+ ` in ${node.obj}"`,
				vueLoopAttr = [{ name: 'v-for', val: loop, mustEscape: false }]
			if(node.key && node.key.toLowerCase() == 'key') 
				vueLoopAttr.push({name: ':key', val: `"${node.key}"`, mustEscape: false })
			const children = processNodes(node.block.nodes)
			nodes[i] = processControlNode(children, vueLoopAttr, `empty v-for=${loop}`)
		}

	}
	return nodes
}

function processControlNode(items, vueAttr, emptyStr)
{
	if(!items.length)
		return {
			type: 'Comment', val: emptyStr, buffer: true, line: node.line, column: node.column, filename:node.filename 
		}

	if(
		items.length > 1 ||
		!items[0].attrs ||
		items[0].attrs.find(a => /^v-(for|if|else)/.test(a.name))
	)
		return {
			block: { type: 'Block', nodes: items }, attrs: vueAttr,
			type: 'Tag', name: 'template', selfClosing: false, attributeBlocks: [], isInline: false
		}

	items[0].attrs.push(...vueAttr)
	return items[0]
}