2020683 - For Gecko Preference Experiments, the `default:` FML stanza should cause an error on Android

Status: RESOLVED FIXED

(Application Services :: Nimbus SDK, task)

Description

[Olivia Hall [:olivia]]

Right now, default: is a valid Gecko preference experiment stanza in Android, e.g.:

  gecko-nimbus-validation:
    description: "Feature for validating Nimbus Gecko functionality"
    variables:
      test-preference:
        description: "A test gecko preference"
        type: String
        default: ""
        gecko-pref:
          pref: "gecko.nimbus.test"
          branch: "default"

We should remove default as a valid element for now because:

1. Gecko preferences should have their default value set Gecko side
2. Desktop does not support this stanza
3. We do not have a mechanism to capture and set default values

This could be a possible enhancement or change in the future, but for right now, it makes the most sense to prevent it to prevent confusion.

Comment 1

[Olivia Hall [:olivia]]

Breaking change warning: Before landing, check that the test experiment, gecko-nimbus-validation, has had default: "" removed.

Expect it to be removed in bug 2012763, but it needs to be checked before landing Nimbus changes that makes default FML invalid.

Comment 2

[Olivia Hall [:olivia]]

(Soft depends on bug 2012763, for landing purposes, otherwise needs to coordinate a removal.)

Comment 3

[BMO Github Automation]

Attachment: [mozilla/application-services] Bug 2020683 - Disallow simultaneous gecko-pref and default on FML variables (#7283)

Comment 4

[BMO Github Automation]

Authored by https://github.com/freshstrangemusic
https://github.com/mozilla/application-services/commit/822db3851779f9a370c56758aaa619612c291919
[main] Bug 2020683 - Disallow simultaneous gecko-pref and default on FML variables (#7283)