Function applyTreeChanges

src/utils/walkerToTreeEntryMap.js:199–304

({
  fs,
  dir,
  gitdir,
  stashCommit,
  parentCommit,
  wasStaged,
})

}

export async function applyTreeChanges({
  fs,
  dir,
  gitdir,
  stashCommit,
  parentCommit,
  wasStaged,
}) {
  const dirRemoved = []
  const stageUpdated = []

  // analyze the changes
  const ops = await _walk({
    fs,
    cache: {},
    dir,
    gitdir,
    trees: [TREE({ ref: parentCommit }), TREE({ ref: stashCommit })],
    map: async (filepath, [parent, stash]) => {
      if (
        filepath === '.' ||
        (await GitIgnoreManager.isIgnored({ fs, dir, gitdir, filepath }))
      ) {
        return
      }
      const type = stash ? await stash.type() : await parent.type()
      if (type !== 'tree' && type !== 'blob') {
        return
      }

      // deleted tree or blob
      if (!stash && parent) {
        const method = type === 'tree' ? 'rmdir' : 'rm'
        if (type === 'tree') dirRemoved.push(filepath)
        if (type === 'blob' && wasStaged)
          stageUpdated.push({ filepath, oid: await parent.oid() }) // stats is undefined, will stage the deletion with index.insert
        return { method, filepath }
      }

      const oid = await stash.oid()
      if (!parent || (await parent.oid()) !== oid) {
        // only apply changes if changed from the parent commit or doesn't exist in the parent commit
        if (type === 'tree') {
          return { method: 'mkdir', filepath }
        } else {
          if (wasStaged)
            stageUpdated.push({
              filepath,
              oid,
              stats: await fs.lstat(join(dir, filepath)),
            })
          return {
            method: 'write',
            filepath,
            oid,
          }
        }
      }