stack transition

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)

var data = [
      { year: 2005, bananas: [10, 20, 30, 40], apples: [20, 10, 30, 50], pears: [30, 10, 20, 50] },
      { year: 2006, bananas: [30, 40, 20, 10], apples: [20, 10, 10, 50], pears: [30, 20, 20, 50] },
      { year: 2007, bananas: [10, 30, 30, 40], apples: [20, 10, 30, 50], pears: [40, 10, 20, 50] }
     ]
    
    const BAR_HEIGHT = 50
    const FRUITS = ['bananas', 'apples', 'pears']
    const COLORS = ['#21CD69', '#f8bc29', '#fb4848', '#ccc']
    
    svg.selectAll('g.stack')
    	.data(FRUITS)
    	.enter().append('g')
    	.attr('class', 'stack')
    	.attr('transform', (d, i) => `translate(0, ${i * (BAR_HEIGHT + 10)})`)
    
    function update (year) {
      var filteredData = data.filter(i => i.year === year)[0]
      
			svg.selectAll('g.stack').nodes()
      	.forEach((node, i) => {
        	const fruitName = FRUITS[i]
        	const t = d3.transition().duration(1000)
        	const stack = d3.select(node)
          	.selectAll('rect')
          	.data(filteredData[fruitName], d => d)
         	stack.exit()
          	.transition(t)
          	.attr('width', 0)
          	.remove()
          
          let x = 0
          stack.enter().append('rect')
          	.attr('y', 0)
          	.attr('height', BAR_HEIGHT)
          	.merge(stack)
          	.attr('fill', (d, i) => COLORS[i])
          	.transition(t)
          	.attr('x', (d, i) => {
            	const retX = x
              x += d * 5
              return retX
          	})
          	.attr('width', d => d * 5)
      	})
    }
    
    let year = 2005
    let inc = 0
    update(year)
    
    setInterval(() => {
      inc = (inc + 1) % 3
      update(year + inc)
    }, 2000)

</script>
</body>

https://d3js.org/d3.v4.min.js