Recursive / nested source map analysis?

[n8sabes]

I'm not sure where to start to investigating why this recursive / nested source map of the same chunk sizes is happening so it can be fixed, if necessary. Is this an artifact of how source-map-explorer visualizes the maps, or how create-react-app is building, etc.? How can it be fixed?

This is a new behavior I've not noticed before and seems messy.

Any input is appreciated.

[nikolay-borzov]

Please provide the exact CLI command. What is result looks like in JSON format?
This is blank CRA

[n8sabes]

Thank you @nikolay-borzov. I am running yarn source-map-explorer 'build/static/js/*.js' against the project and get the weird result shown in the initial post. I have not ejected the CRA project, so it's using built-in scripts.

A moment ago, I created clean CRA project and get the same analysis as you (pretty clean).

Is the weird recursive nesting artifact normal, or abnormal for a mature project? Any advice in how to find the cause and fix it would be hugely appreciated. I don't quite know how to refer to this issue to do searches on it.

Not sure if it's relevant, but this is my tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "lib": [
      "dom",
      "dom.iterable",
      "esnext"
    ],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "preserve",
    "outDir": ".build",
    "rootDir": "./",
  },
  "include": [
    "./src",
    "./typings"
  ],
  "exclude": [
    "node_modules"
  ]
}

[nikolay-borzov]

Is the weird recursive nesting artifact normal, or abnormal for a mature project?

A visualization like this looks abnormal to me.

Could post the result of yarn source-map-explorer 'build/static/js/*.js' --json?

Each visualization node is built from files key. For example

  "../node_modules/react-dom/cjs/react-dom.production.min.js": {       
    "size": 117513                                                     
  },                                                                   

Turns into 5 nested nodes

[n8sabes]

@nikolay-borzov, Apologies for the slow response. I believe I found the cause of the anomaly!!

Because I develop on several systems at different locations, I use Dropbox to sync files in-real-time and then use git to manage the repo. This enables me to move freely between systems without worrying about dropping any work. HOWEVER, because Dropbox does not have a "true ignore" feature without reindexing (horridly slow), I use a symlink to ~/Downloads/project_name/node_modules. When this symlink is in place, the weird nesting happens. It seems like a perfect sync solution, but this is a newly discovered and unexpected side-effect.

STEPS TO USE A SYMLINK:

1. cd YOUR_PROJECT_NAME
2. mkdir -p ~/Downloads/node_modules_for_YOUR_PROJECT_NAME
3. mv node_modules ~/Downloads/node_modules_for_YOUR_PROJECT_NAME
4. ln -s ~/Downloads/node_modules_for_YOUR_PROJECT_NAME/node_modules

A post in the Dropbox Community discussing the issue and steps can be found: Here

QUESTIONS:

1. Is the use of a symlink causing any real inefficiencies in the build, or is this just a zero-cost artifact of the build / source-map-analyzer?
2. What is really happening here?
3. Do you know of a way to resolve the anomaly while preserving the use of a symlink?

[edit: removed .json dump]

[n8sabes]

I think this is the same issue as #137, Collapse non-contributing directories.