src/utils/file.js
function fetch(repoState, driver, filepath) {
    if (isFetched(repoState, filepath)) {
        // No op if already fetched
        return Q(repoState);
    }

    const workingState = repoState.getCurrentState();
    const blobSha = WorkingUtils.findSha(workingState, filepath);

    return BlobUtils.fetch(repoState, driver, blobSha);
}
function fetch(repoState, driver, filepath) {
    if (isFetched(repoState, filepath)) {
        // No op if already fetched
        return Q(repoState);
    }

    const workingState = repoState.getCurrentState();
    const blobSha = WorkingUtils.findSha(workingState, filepath);

    return BlobUtils.fetch(repoState, driver, blobSha);
}
Fetch a file blob. Required for content access with
stat/read. No-op if the file is already fetched.
@param {RepositoryState} repoState
@param {Driver} driver
@param {Path} filepath
@return {Promise<RepositoryState>}