Add safeEmpty, safeDefault, and safeCoalesce functions which don't consider 0 or false to be empty

[tculp]

As explained in #111, the current implementation of empty, and therefore default and coalesce, fails when attempting to use booleans or certain integers. However, there are many cases where an override value may be a legitimate 'false' or '0'.

For example, in helm charts, a paradigm such as follows is common:

values.yaml

global:
  doThing: true

doThingOverride: null

deployment.yaml

{{- if .Values.doThingOverride | default .Values.global.doThing }}

In this case, even if doThingOverride is set to false, the global.doThing will always be used.

Adding a new set of functions would allow this paradigm to work without unfortunate workarounds like {{- if eq (coalesce (.Values.enableIngressOverride | quote) (.Values.global.enableIngress | quote)) (true | quote) }} and maintain backwards-compatabiity

[govindbalaji-s]

Is this still open? Can I pick this?

[tculp]

Is this still open? Can I pick this?

Sure, glad to see something done with this!