==. For comparison, use
[ "$var" = value ].
[ "$a/$b" = "foo/bar" ]
ShellCheck found a command name that contains a
==. Most likely, this was intended as a kind of comparison.
To compare two values, use
[ value1 = value2 ]. Both the brackets and the spaces around the
= are relevant.
None, though you can quote the
== to suppress the warning.
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.