When I ran into that situation in the past, the imports had reasonable names (e.g. "fd_write"). Which WebAssembly toolchain is just using letters of the alphabet? Is that common practice now?
It seems libjxl does not compile for WASI, but for emscripten. Hence that minified JS is likely the emscripten glue code that's required at runtime, but which the libjxl documentation fails to mention clearly (as it just tells users to run some python script and get a magic file included at runtime). To run that outside the browser, the author will need to generate a emcripten runtime that works with WASI, which as far as I know is not possible.
When I ran into that situation in the past, the imports had reasonable names (e.g. "fd_write"). Which WebAssembly toolchain is just using letters of the alphabet? Is that common practice now?