- `bash` mode makes braces pass 100% of the bash unit tests (the only tests Braces doesn't pass are the 8 to 10 tests for bash `${var}` variables). But node.js isn't bash, so I'm turning this mode off by default. The main difference between `bash` mode and non-bash mode, is that when bash mode is turned on, braces with single items (e.g. non-sets) are returned **with** braces. e.g. `{a}` is left unchanged. as is `a{b}c` and similar patterns. When bash mode is off, the braces are removed, so `a` and `abc` are returned, respectively.