Simple line chart

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v3.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    .line {
      fill: none;
      stroke: black;
      stroke-width: 1.5px;
    }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)

var width = 800;
    var height = 400;

// https://bl.ocks.org/zanarmstrong/raw/05c1e95bf7aa16c4768e/
    var parseDate = d3.time.format("%Y-%m");
    var displayDate = d3.time.format("%b %y");
    var displayValue = d3.format(",.0f");
    
    // Ordinal scale
    var x = d3.scale.ordinal()
        .rangeRoundBands([0, width], .5);

var y = d3.scale.linear()
        .range([height, height - 200]);

var line = d3.svg.line()
        .x(function(d) { return x(d.name); })
        .y(function(d) { return y(d.value); });
    
    var g = svg.append("g")
    	.attr("transform", "translate(50, 0)")
    
   	d3.json("dataset.json", function(data) {

// Pre-processing
      data.forEach(function(d) {
				d.value;// = +d.value;
        d["date"] = parseDate.parse(d["date"]);
      });
      
      x.domain(data.map(function(d) { return d.name; }));
			y.domain([0, d3.max(data, function(d) { return d.value; })]);
      
      svg.selectAll("text").data(data).enter()
       .append("text")
        .text(function(d, i) { return displayDate(d.date); })
        .attr("y", 420)
        .attr("x", function(d) { return x(d.name); })
        .style("font-size", 10)
        .style("font-family", "monospace");

g.selectAll(".value").data([data[data.length -1]]).enter()
       .append("text")
        .text(function(d, i) { return displayValue(d.value); })
        .attr("class", "value")
        .attr("y", function(d) { return y(d.value); })
        .attr("x", width - 20)
        .style("font-size", 20)
        .style("font-family", "monospace");

g.selectAll("path").data([data]).enter().append("path")
        .attr("class", "line")
        .attr("d", line);

var circles = g.selectAll('circle').data(data);

var nodes = g.selectAll("g")
          .data(data).enter()
          .append("g");

nodes.append('circle').attr('class', 'circle')
                            .attr("cx", function(d, i) { return x(d.name); })
                            .attr("cy", function(d, i) { return y(d.value); })
                            .attr("r", 10)
                            .style("fill", "grey")
                            .style( "opacity", 0.25)

nodes.append('text').attr('style', 'display:none;')
                          .text(function(d) { return d.value; })
                          .attr('x', function(d) { return x(d.name); })
                          .attr('y', function(d) { return y(d.value) - 20; });
                      
      nodes.append("path")
                        .attr("id", function(d,i) { return "path"+ d.name; })
                        .attr("class", "line")
                        .attr('style', 'display:none;')

nodes.selectAll('.circle').on('mouseover', function( d, i) {

d3.select(this).style("fill", "red").style( "opacity", 0.9);
            nodes.selectAll("text").filter(function(e) {
                                      return d.name === e.name;
                                   })
                                   .attr('style', 'display:inline;')
                                   .style("font-size", function(d,i){return 14;})
                                   .style("font-family", "monospace");

nodes.selectAll("path").attr("d", lineFunction(tmpLine))
                                   .filter(function(e) {
                                      return d.name === e.name;
                                   })
                                   .attr('style', 'display:inline;')
                                   .style("stroke-dasharray", ("3, 3"))

});

nodes.selectAll('.circle').on("mouseout", function( data, index) {
              d3.select(this).transition().duration(100).style("fill", "grey").style( "opacity", 0.25);
              nodes.selectAll("text").transition().duration(100).attr('style', 'display:none;');
              nodes.selectAll("path").transition().duration(100).attr('style', 'display:none;');
      })
      
    });

</script>
</body>

https://d3js.org/d3.v3.min.js