The curious case of /public/assets/ in a Meteor project

Question

In my Meteor 1.10.2 project, I have created a folder called assets inside the /public/ folder. When the Meteor application is built, I find this assets folder has been copied to these locations, as a direct child of the web.browser... folders:

/.meteor/local/build/programs/web.browser/assets/
/.meteor/local/build/programs/web.browser.legacy/assets

However, if I rename the folder to Assets (or if I give it any other name), when the application is built, I find it deeper in, inside the app folder at:

/.meteor/local/build/programs/web.browser/app/Assets/
/.meteor/local/build/programs/web.browser.legacy/app/Assets/

What is the logic behind this? What is the intention? What are the best practices for working with a folder at /public/assets/? Are there any other words that are given special treatment when used as names for folders inside the /public/ folder?

Answer 1

FWIW, this behaviour is specifically due to meteor tools bundler:

https://github.com/meteor/meteor/blob/release/METEOR%401.10.2/tools/isobuild/bundler.js#L719-L725

  setTargetPathFromRelPath(relPath) {
    // XXX hack
    if (relPath.match(/^(packages|assets|dynamic)\//)) {
      this.targetPath = relPath;
    } else {
      this.targetPath = files.pathJoin('app', relPath);
    }

Therefore we can see that there are 3 special directory names that exhibit this special behaviour:

• packages
• assets
• dynamic

Example with public assets:

These assets bundled in build:

For "packages", while we can understand that this is how Meteor ships the static assets of packages (i.e. when they call api.addAssets(), we can also see that there is a potential for collision, in the (however unlikely) case we use a pathname like "public/packages/my-package-name".

As for "assets", the initial name was "static", but I do not think it was publicly documented either.

And for "dynamic", I do not know yet what is its exact purpose, but we can see that it serves its content as "javascript" type (at least SVG files), whereas the first 2 serve them as "text/plain".