Documentation on wiki
WIP audit of existing MobileFrontend components
- MobileFrontend makes heavy use of inheritance rather than composition - this makes it harder to create new features
- MobileFrontend uses Hogan.js for templating which is not supported in core and requires bespoke code making it harder to create features that span desktop and mobile.
- MobileFrontend has a CSS problem - it's very easy to cause UI regressions due to badly organised CSS rules that can cause one component to cause UI regressions in another component.
- MobileFrontend has no UI component library so it's not easy to verify if all components are rendering correctly.
- Many of MobileFrontend's codebase has bad code coverage
- The behaviour of MobileFrontend's components is unpredictable due to the inheritance chain and side effects of events via a global event bus.
- Separation of concerns, separating UI and network and business logic
- Making our code more easily testable
- Better unit tests, with less mocking and code units with less scope
- Using composition instead of inheritance in the UI components
- Declarative UI rendering
- Doing away with the direct DOM manipulation paradigm and using a declarative rendering library for the Minerva skin UI components
- Replacing larger feature specific components with new reusable components
- We should monitor the number of files in src/ and resources/ We should expect the number of files in src to increase (and possibly decrease at times) to reflect redundant code being removed
- We will measure the number of components extending the View class. We hope this will go up as we move away from large multi-concerned components to dumb components.
- Code coverage will be added during refactoring, so we should report code coverage (at least weekly) to give a sense of how well this is going.
- We will monitor JS and CSS asset size, which will hopefully decrease as we make our code more reusable.
We will know if we have been successful when:
- We are capable of building a UI component library using a tool such as storybook
- It's possible to extract Mobile's components into a well documented external library e.g. T144402
- All components in MobileFrontend have at most one level of inheritance - e.g. an Overlay extends View.
- It is clear why the resources folder exists and what files go into it (instead of resources)
- Code coverage has increased from 50%
- T94086 has been resolved and it's clear what we are doing with templates going forward.
- Feature development of an overlay is documented and clear
- We have made a decision about use of EventBuses (see previous spike in T211724)