In an effort to level up my Javascript learning, I took an ES6 course. It was recommended by a developer on my team as a stepping stone to learning React. As part of the course, I created a Proof of Concept that showed a long error message. The error message appears expanded to begin with, to view all generated errors but can be collapsed to conserve space while correcting issues within the document. In addition, this error message floats above the content, allowing the user to scroll through the document to find the errors and correct them.
See the Pen ES6 Collapsible Toast Message by Samantha Howes (@dusterbed) on CodePen.