Error Rate Comparison Changelog Block for React

Edit ERROR_CLASSES at the top of the file. Each class has a label, a note and fourteen days: errors per 10,000 requests, the first seven before the release and the last seven after. The averages, the change in percent, the lines and the title are all worked out from those numbers. The release name and the three dates above the lines are constants beside them.

Off, each row's line is drawn on its own range, so even a quiet class shows its shape. On, every row shares one range from zero to the busiest day anywhere, so the lines can be compared by height. The text, the values and the page's height never change, and a short line under the title says which scale is in use.

By an arrow, a sign and, for assistive technology, words: a class that fell shows a down arrow and a true minus, one that rose shows an up arrow and a plus, and a hidden phrase says "fewer errors" or "more errors" than before the release. The pale and full-weight parts of each line tell before from after.

The lines are hidden from assistive technology. A table with a caption lists every class and its fourteen daily values, and each row's heading, average and change are text.

Below the desktop width each line drops under its label and the value and change sit side by side. The lines themselves stay left to right, because time runs one way on them. In a right-to-left layout the text and rows mirror, while versions, dates, percentages and signed changes, which are data, keep their order.