LOOSE mode includes ES6 modules that aren't imported by the entry point

[ghost]

I'm trying to convert our code from goog.provide modules to ES6 modules, but I've run into a difference in behavior that I didn't expect. When running in LOOSE dependency mode, the compiler includes all ES6 modules regardless of whether they're a dependency of the entry point. When I used goog.provide, these files were excluded from compilation. Based on https://github.com/google/closure-compiler/wiki/Managing-Dependencies#working-with-files-that-do-not-specify-dependencies, I'd expect the ES6 modules to work the way goog.provide modules do.

Running in STRICT mode eliminates files that aren't imported by the entry point, but it also eliminates non-module files (as expected). We have some non-module legacy files that we include in some of our builds, so I don't want to switch to STRICT if I can avoid it.

Can you make ES6 modules work like goog.provide, or at least clarify that section of the wiki?

Thanks!

[ChadKillingsworth]

Closed by #2641