[MNG-6056] Implement Feature Toggle Module to handle Feature Toggles

• Type: Task
• Status: Closed
• Priority: Minor
• Resolution: Abandoned
• Affects Version/s: needing-scrub-3.4.0-fallout
• Assignee: Karl Heinz Marbaise
• Reporter: Karl Heinz Marbaise
• Created: 02/Jul/16 20:47
• Updated: 23/Dec/19 12:33
• Resolved: 23/Dec/19 12:33

Description

Implement a feature toggle module to handle feature toggles in Maven. The best from my point of view at the moment is having a relationship to the JIRA which defines all kinds of bugs, issues and of course features.

Create a separate module: maven-feature to have no other dependency which means it can be integrated into any other module of maven.

Add appropriate command line option like --activate-features to activate one or more features in one go. This prevents us from changing the command line every time we add or remove a feature toggle.

So a command line option could look like this:

mvn --activate-features MNG2345,MNG1299 clean package

This will activate the features MNG2345 and MNG1299. If you try to activate a feature toggle which does not exist we should simply print out a warning and just continue. This will simplify also future changes which means if 3.4.0 introduces a feature toggle MNG-XXXX but in Maven 3.5.0 this feature toggle does not exists anymore or made default calling the command line that way will only produce a warning nothing more.

It should be compile time save which means if the feature toggle will be removed the compiler should show where this features has been used or questioned if it is activated. This will simplify the removal of the dependent code.

Simplify adding of new feature toggles.

Currently the best seemed to be an enumeration which contains this information.

It should also be possible to list all available feature toggles via command line option like --list-features which should print out the existing feature toggles plus an appropriate description for the user (in particular intended for maven devs).

It should also be simple to query for a feature toggle like:

  @Requirement
  private SelectedFeatures featureToggle;
  ...
  if (featureToggle.isFeatureActive(Feature.MNG10000)) {
    // The feature is implemented here or a different selection is done.
  }

Issue Links

• blocks: MNG-6058 Test dependencies should override application dependencies only during testing
• blocks: MNG-5988 Dependency mediation should prioritize transitive dependencies based on scope.
• blocks: MNG-5761 Dependency management is not transitive.
• blocks: MNG-6006 Import Aether to Maven codebase