node-source-walk
Execute a callback on every node of a source code's AST and stop walking when you see fit
string-left-right
Looks up the first non-whitespace character to the left/right of a given index
jsonpath
Query JavaScript objects with JSONPath expressions. Robust / safe JSONPath engine for Node.js.
treeverse
Walk any kind of tree structure depth- or breadth-first. Supports promises and advanced map-reduce operations with a very small API.