src/utils/file.js
function write(repoState, filepath, content) {
    if (!exists(repoState, filepath)) {
        throw error.fileNotFound(filepath);
    }

    const change = Change.createUpdate(content);
    return ChangeUtils.setChange(repoState, filepath, change);
}
function write(repoState, filepath, content) {
    if (!exists(repoState, filepath)) {
        throw error.fileNotFound(filepath);
    }

    const change = Change.createUpdate(content);
    return ChangeUtils.setChange(repoState, filepath, change);
}
Write a file (must exists)
@return {RepositoryState}