in src/helpers/whatif.ts [672:686]
function formatLeaf(builder: ColorStringBuilder, value: UnknownValue): void {
if (value === null) {
builder.append("null");
} else if (typeof value === "boolean") {
builder.append(String(value).toLowerCase());
} else if (typeof value === "string") {
builder.append(Symbol.Quote).append(value).append(Symbol.Quote);
} else if (Array.isArray(value) && value.length === 0) {
builder.append("[]");
} else if (typeof value === "object") {
builder.append("{}");
} else {
builder.append(String(value));
}
}