base64Encode doesn't expand variables

[failshell]

Bug

Current Behavior

if you use something like ${base64Encode("mongodb+srv://user:${secrets.mongodb-user-password}@mongodb-headless.${var.kubernetes.namespace}.svc.cluster.local/?ssl=false&replicaSet=rs0&authSource=db")} to encode a string, the variables in between the double quotes won't be expanded. you're going to end up with the litteral string.

Expected behavior

variables should be expanded to their proper values.

Workaround

i've set a variable with "mongodb+srv://user:${secrets.mongodb-user-password}@mongodb-headless.${var.kubernetes.namespace}.svc.cluster.local/?ssl=false&replicaSet=rs0&authSource=db" as a value and used that variable like so ${base64Encode(var.example.mongoDBConnectionString)} and i ended up with the proper string.

Your environment

garden version: 0.12.21
os: macOS