Create a stream graph from CSV data

This is probably more a question around D3, rather than Observable - so if it’s off-topic, please feel free to close it.

In essence, in https://beta.observablehq.com/@cfax/stream-graph I’m trying to build a stream graph, from a very simple CSV file.

What is not entirely clear to me, is how I can manipulate the tabular data into a data structure that could be used to plot the graph - I feel I might not be doing the right thing and I’m overcomplicating the code.

For instance, I’m not entirely sure how to craft the area function to return the first column of the CSV (namely “buildNumber”) - is my attempt correct?

Hey - was this example updated after you posted the topic, because it looks like you’ve succeeded at creating a streamgraph, though with the very limited range of data it’s not much different than a stacked area chart.