I’ve figured it out!

Like the original post, I’m working with Calendar module. I wanted to understand why we could write, say symbol: “cloud” instead of having to declare the full “fas fa-fw fa-cloud” to invoke the symbol.

I went into /modules/default/calendar/calendar.js and noticed the following section of code:

const symbols = this.symbolsForEvent(event);
                                symbols.forEach((s, index) => {
                                        const symbol = document.createElement("span");
                                        symbol.className = "fas fa-fw fa-" + s;
                                        if (index > 0) {
                                                symbol.style.paddingLeft = "5px";
                                        }
                                        symbolWrapper.appendChild(symbol);
                                });
                                eventWrapper.appendChild(symbolWrapper);
                        } else if (this.config.timeFormat === "dateheaders") {
                                const blankCell = document.createElement("td");
                                blankCell.innerHTML = "   ";
                                eventWrapper.appendChild(blankCell);
                        }

calendar.js is hardcoding the fas (solid) font family in, not allowing us to invoke a family like fab (brands). setting the line:

symbol.className = "fas fa-fw fa-" + s;

to just:

symbol.className = s;

forces us to redeclare every symbol in config.js from “cloud” to “fas fa-fw fa-cloud”, but we can now access all available FA icons.

And so, I get my leaf :)

Screen Shot 2022-04-28 at 17.37.44