When the source file is minified, it is not human readable (for mere mortals) in “Sources” tab of Chrome dev-tools. Chrome provides a way to help you out in such scenarios.
You can make it legible by using PrettyPrint {}
icon just below. You may also find Pretty Print
Button shown on top of the file, to perform the same functionality. It transforms the current file into human-readable form.
Pretty Print or Format options only un-minifies the source file. It does not help in tackling uglification/obfuscation of code. To achieve those, source maps (if available) can also be used.