Smart parens strict mode
By running smart parens in strict mode it stops you from making simple errors with your structured code, like unbalanced parens.
~/.spacemacs configuration file,
SPC f e d, and update
dotspacemacs-smartparens-strict-mode the configuration to have a value of
See examples of what smart parens can do by looking at the Animated guide to paredit
See the article on Paredit and smartparens for a comparison of these two packages.