The usual trick for spacing is to just add a little fudge factor:
.attr("x", function(d) { return x(d.data.race) + 2; }) //<-- move right two pixels to stay centered
.attr("y", function(d) { return y(d[0] + d[1]); })
.attr("height", function(d) { return y(d[0]) - y(d[0] + d[1]); })
.attr("width", x.bandwidth() - 4) //<-- shorten width by 4
For your tooltip you are using a code snippet from an older version of d3. For d3.js version 6, the callback was modified to pass the event object where you can get the cursor position:
.on("mousemove", function(e,d) {
var xPosition = e.offsetX - margin.left + 10;
var yPosition = e.offsetY - margin.top - 10;
tooltip.attr("transform", "translate(" + xPosition + "," + yPosition + ")");
tooltip.select("text").text(d[1]);
});
Working code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="">
<meta name="author" content="">
<title>Communities Fighting Covid</title>
<!-- Bootstrap core CSS -->
<link href="vendor/bootstrap/css/bootstrap.min.css" rel="stylesheet">
<!-- Custom styles for this template -->
<link href="css/modern-business.css" rel="stylesheet">
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/6.2.0/d3.min.js"></script>
</head>
<body>
<script>
var margin = {top: 20, right: 160, bottom: 35, left: 30};
var width = 960 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var svg = d3.select("body")
.append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
/* Data in strings like it would be if imported from a csv */
var data = [
{ race: "A", positive: "60", total: "600"},
{ race: "C", positive: "58", total: "500"},
{ race: "D", positive: "85", total: "600"},
{ race: "E", positive: "56", total: "500"},
{ race: "F", positive: "89", total: "700"},
{ race: "G", positive: "62", total: "400"}
];
// Transpose the data into layers
var keys= ["positive", "total"];
var dataset = d3.stack().keys(keys)(data);
// Set x, y and colors
var x = d3.scaleBand()
.domain(data.map(function(d) { return d.race; }))
.range([10, width-10], 0.02);
var y = d3.scaleLinear()
.domain([0, d3.max(dataset, function(d) { return d3.max(d, function(d) { return d[0] + d[1]; }); })])
.range([height, 0]);
var colors = ["b33040", "#d25c4d"];
// Define and draw axes
var yAxis = d3.axisLeft()
.scale(y)
.ticks(5)
.tickSize(-width, 0, 0)
.tickFormat( function(d) { return d } );
var xAxis = d3.axisBottom()
.scale(x)
.tickFormat(data.race); // change this to get x values to reflect new
svg.append("g")
.attr("class", "y axis")
.call(yAxis);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
// Create groups for each series, rects for each segment
var groups = svg.selectAll("g.cost")
.data(dataset)
.enter().append("g")
.attr("class", "cost")
.style("fill", function(d, i) { return colors[i]; })
var rect = groups.selectAll("rect")
.data(function(d) { return d; })
.enter()
.append("rect")
.attr("x", function(d) { return x(d.data.race) + 2; })
.attr("y", function(d) { return y(d[0] + d[1]); })
.attr("height", function(d) { return y(d[0]) - y(d[0] + d[1]); })
.attr("width", x.bandwidth() - 4)
.on("mouseover", function() { tooltip.style("display", null); })
.on("mouseout", function() { tooltip.style("display", "none"); })
.on("mousemove", function(e,d) {
var xPosition = e.offsetX - margin.left + 10;
var yPosition = e.offsetY - margin.top - 10;
tooltip.attr("transform", "translate(" + xPosition + "," + yPosition + ")");
tooltip.select("text").text(d[1]);
});
// Draw legend
var legend = svg.selectAll(".legend")
.data(colors)
.enter().append("g")
.attr("class", "legend")
.attr("transform", function(d, i) { return "translate(30," + i * 19 + ")"; });
legend.append("rect")
.attr("x", width - 18)
.attr("width", 18)
.attr("height", 18)
.style("fill", function(d, i) {return colors.slice().reverse()[i];});
legend.append("text")
.attr("x", width + 5)
.attr("y", 9)
.attr("dy", ".35em")
.style("text-anchor", "start")
.text(function(d, i) {
switch (i) {
case 0: return "Total Cases";
case 1: return "Positive Cases";
}
});
// Prep the tooltip bits, initial display is hidden
var tooltip = svg.append("g")
.attr("class", "tooltip")
.style("display", "none");
tooltip.append("rect")
.attr("width", 30)
.attr("height", 20)
.attr("fill", "white")
.style("opacity", 0.5);
tooltip.append("text")
.attr("x", 15)
.attr("dy", "1.2em")
.style("text-anchor", "middle")
.attr("font-size", "12px")
.attr("font-weight", "bold")
.attr("fill", "black")
</script>
</body>