.cljs.edn files are configuration files for Boot-cljs which allow options
being set in a separate file instead of in build.boot task call.
There are several benefits to providing configuration in separate files:
Using separate file is that the options can be changed without restarting the whole Boot process.
It is possible to calculate some options based on the
relative path of .cljs.edn file inside the fileset. If user doesn't
provide :output-dir or :output-to options, the values are set up using
relative path of the .cljs.edn file.
Perhaps the most important feature of .cljs.edn files is that other tasks
can modify this configuration. For example Boot-reload and Boot-cljs-repl
use this set up their code using :require.
Boot-cljs is able to run several Cljs compiler parallel if multiple
.cljs.edn files are present.
NOTE: This might change. Cljs compiler can now work parallel itself, if
:parallel-buildoption is enabled. For cases there the application should be split to several JS files,:modulesis probably better fit as that way the shared code is not duplicated to every output file. For cases where separate builds, like app and tests, are needed, it might be simpler to just run two cljs tasks.
Compiler options can be provided here.
Collection of namespaces to require in Boot-cljs generated main namespace.
Collection of functions (namespaced symbols) to call from Boot-cljs main namespace,
called after all the :require namespaces are loaded.
Namespaces of these symbols are automatically added to :require.