# config: (vim -u)
# set foldmarker={,}
# set foldmethod=marker

# {
foo() {
  bar="{,}"    # <- folds correctly
  bar="{ 1,1}" # <- folds correctly
  bar="{1}"    # <- breaks folding!
  # folding breaks because of an integer (in this case 1)
  # attached to the left fold marker
}
# }