src/context.js
function getFile(group) {
  while (group) {
    if (group.file) return group.file
    group = group.parent
  }
}
function getFile(group) {
  while (group) {
    if (group.file) return group.file
    group = group.parent
  }
}
function getFile ( group ) { while ( group ) { if ( group . file ) return group . file group = group . parent } }
Find which file the given group is in.
Find which file the given group is in .