development env: is the asset pipeline expected to compile all assets or just those in demand?

I'm trying to understand if, in development, the asset pipeline is supposed to compile ALL assets found in manifest.js or just the ones that are requested.

I've been doing some testing and have found that it appears all assets are compiled even when only a singular small asset is requested. This for us can be extremely slow.

It would seem to me that all assets are compiled even if a singular, small, asset is requested. This, for us, is very slow.

In development, the asset pipeline typically compiles only requested assets and their dependencies. If it's compiling all assets, it could be due to:

Manifest Configuration: Broad directives like require_tree . in manifest.js might load everything.
Dependencies: A requested asset may depend on others, triggering additional compilations.
Configuration Flags: Certain settings might force precompilation.
To fix this:

Simplify manifest.js to include only necessary assets.
Enable debugging (e.g., config.assets.debug = true in Rails) to load assets individually.
Precompile large, infrequently changing assets if needed.
snow rider

It sounds like you're encountering an issue with the asset pipeline compiling more assets than needed during development. Typically, the pipeline is designed to compile assets based on what's requested, but in some setups, it may compile all assets listed in the block blast manifest.js, even if only one is being used.

It might be that your configuration is causing the pipeline to compile all assets instead of just the requested ones. You could try using require instead of require_tree to specify exactly which assets are needed. Also, make sure there are no settings forcing the compilation of all assets even when it's not necessary.