You can set the flag --warning_level=VERBOSE
, which is equivalent to
--jscomp_warning=checkTypes --jscomp_error=checkVars \
--jscomp_warning=deprecated --jscomp_error=duplicate \
--jscomp_warning=globalThis --jscomp_warning=missingProperties \
--jscomp_warning=undefinedNames --jscomp_error=undefinedVars
There are still some checks which will be off and which you have to enable explicitly if you want them. There is no way afaik to enable all by default.
For a complete list of warning/error types, see https://code.google.com/p/closure-compiler/wiki/Warnings.