default template function treats 0 value as unspecified

[Endevir]

Hi!
I've encountered an interesting problem with helm templating engine: default function treats 0 (integer) values as unspecified and uses $default parameter.

---

A small example:
Having single templating yaml and values:

template.yaml:

apiVersion: v1
kind: Something
metadata:
  name: {{ default 1 .Values.myvalue0 }}
  surname: {{ default 1 .Values.myvalue555 }}

values.yaml

myvalue0: 0
myvalue555: 555

Running helm template test test

Received output:

---
# Source: test/templates/template.yaml
apiVersion: v1
kind: Something
metadata:
  name: 1
  surname: 555

Expected output:

---
# Source: test/templates/template.yaml
apiVersion: v1
kind: Something
metadata:
  name: 0
  surname: 555

Seems like helm treats zero values as unspecified and replaces with first argument for default templating function, which is not expected behavior.

---

Output of helm version:

version.BuildInfo{Version:"v3.12.3", GitCommit:"3a31588ad33fe3b89af5a2a54ee1d25bfe6eaa5e", GitTreeState:"clean", GoVersion:"go1.20.7"}

Output of kubectl version:

k version                      (minikube/default)
Client Version: v1.28.0
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.27.4

Cloud Provider/Platform (AKS, GKE, Minikube etc.): Minikube (doesn't actually matter)

[yxxhero]

@Endevir please see https://masterminds.github.io/sprig/defaults.html

[yxxhero]

this is right behavor.