[Blitz Internals] Caching and not-drilling down server config

[svobik7]

As me and @ryardley came to the idea of not-drilling down the server config in there: #878 (comment)

I am opening this threat to discuss if it make sense to create some global place from where the ServerConfig can be easily obtained and avoid passing config params down on multiple places.

My idea is something like this (not tested just came to my mind now):

• Config params should be calculated just once and then cached
• Config params can be forced to recalculate
• There is no need to await for both next-bins

let cachedConfig: NormalizedConfig | null = null

export async function getNormalizedConfig(
  config: ServerConfig,
  useCache: boolean = true,
): Promise<NormalizedConfig> {
  
  if (!useCache || cachedConfig === null) {
   
    // maybe use `config.rootFolder || pkgDir.sync() || process.cwd()`, is it there any benefit using pkgDir?
    const rootFolder = config.rootFolder || process.cwd();

    // do not await for both bin-pkg because always just one is used
    const nextBinPkg = config.interceptNextErrors ? "@blitzjs/server" : "next"
    const nextBinExec = config.interceptNextErrors ? "next-patched" : undefined
    const nextBin = await resolveBinAsync(nextBinPkg, nextBinExec)

    const git = parseChokidarRulesFromGitignore(resolve(process.cwd(), rootFolder))
    const isTypescript = fs.existsSync(path.join(rootFolder, "tsconfig.json"))

    cachedConfig = {
      ...config,
      buildFolder: resolve(rootFolder, config.buildFolder ?? defaults.buildFolder),
      devFolder: resolve(rootFolder, config.devFolder ?? defaults.devFolder),
      ignore: defaults.ignoredPaths.concat(git.ignoredPaths),
      include: defaults.includePaths.concat(git.includePaths),
      nextBin: resolve(rootFolder, nextBin),
      transformFiles: config.transformFiles ?? transformFiles,
      watch: config.watch ?? false,
      writeManifestFile: config.writeManifestFile ?? defaults.writeManifestFile,
      isTypescript: isTypescript ?? true,
    }
  }

  return cachedConfig;
}

I think it would be easily to get current server config with const config = getNormalizedConfig() anywhere in server package.

How does it sound to others?

[flybayer]

Sounds like a good idea to me!

[svobik7]

Cool. Is that something I should start the working on or should I wait for more opinions? :-)

[flybayer]

Go for it :)

[svobik7]

After a small time of investigating in this I came up to resolution that initial idea of caching the server config leads to no benefits. It breaks the "pure" concept of normalize function in server package and makes future testing hard to maintain. So therefore I do not think that server config caching is benefical here any more.

Instead of caching I created PR with small server code refactor and made possible to skip TS checking by explicitly provide new flag --ts --> #1014

[flybayer]

Great, thank you for your investigation and work on this!