jashkenas--coffeescript/documentation/sections/breaking_changes_default_values.md

Default values for function parameters and destructured elements

Per the ES2015 spec regarding function default parameters and destructuring default values, default values are only applied when a value is missing or undefined. In CoffeeScript 1.x, the default value would be applied in those cases but also if the value was null.

codeFor('breaking_change_function_parameter_default_values', 'f(null)')

codeFor('breaking_change_destructuring_default_values', 'a')