Update feature flags documentation for new feature behaviour

docs/feature-flags.md

@@ -35,7 +35,7 @@ clients commit to doing the associated clean up work once a feature stabilises.
 When starting work on a feature, we should create a matching feature flag:
 
 1. Add a new
-   [setting](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.js)
+   [setting](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.ts)
    of the form:
 ```js
     "feature_cats": {
@@ -47,17 +47,9 @@ When starting work on a feature, we should create a matching feature flag:
 ```
 2. Check whether the feature is enabled as appropriate:
 ```js
-    SettingsStore.isFeatureEnabled("feature_cats")
+    SettingsStore.getValue("feature_cats")
 ```
-3. Add the feature to the set of labs on
-   [develop](https://github.com/vector-im/riot-web/blob/develop/riot.im/develop/config.json)
-   and [nightly](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/nightly/config.json):
-```json
-    "features": {
-        "feature_cats": "labs"
-    },
-```
-4. Document the feature in the [labs documentation](https://github.com/vector-im/riot-web/blob/develop/docs/labs.md)
+3. Document the feature in the [labs documentation](https://github.com/vector-im/riot-web/blob/develop/docs/labs.md)
 
 With these steps completed, the feature is disabled by default, but can be
 enabled on develop and nightly by interested users for testing.
@@ -67,7 +59,7 @@ The following lists a few common options.
 
 ## Enabling by default on develop and nightly
 
-Set the feature to `enable` in the
+Set the feature to `true` in the
 [develop](https://github.com/vector-im/riot-web/blob/develop/riot.im/develop/config.json)
 and
 [nightly](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/nightly/config.json)
@@ -75,61 +67,41 @@ configs:
 
 ```json
     "features": {
-        "feature_cats": "enable"
+        "feature_cats": true
     },
 ```
 
 ## Enabling by default on staging, app, and release
 
-Set the feature to `enable` in the
+Set the feature to `true` in the
 [staging / app](https://github.com/vector-im/riot-web/blob/develop/riot.im/app/config.json)
 and
 [release](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/release/config.json)
 configs.
 
-**Warning:** While this does mean the feature is enabled by default for
-https://app.element.io and official Element Desktop builds, it will not be enabled by
-default for self-hosted installs, custom desktop builds, etc. To cover those
-cases as well, the best options at the moment are converting to a regular
-setting defaulted on or to remove the flag. Simply enabling the existing flag by
-default in `Settings.js`
-[does not work currently](https://github.com/vector-im/riot-web/issues/10360).
+**Note:** The above will only enable the feature for https://app.element.io and official Element
+Desktop builds. It will not be enabled for self-hosted installed, custom desktop builds, etc. To
+cover these cases, change the setting's `default` in `Settings.ts` to `true`.
 
 ## Feature deployed successfully
 
-Once we're confident that a feature is working well, we should remove the flag:
+Once we're confident that a feature is working well, we should remove or convert the flag.
 
-1. Remove the [setting](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.js)
-2. Remove all `isFeatureEnabled` lines that test for the feature's setting
+If the feature is meant to be turned off/on by the user:
+1. Remove `isFeature` from the [setting](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.ts)
+2. Change the `default` to `true` (if desired).
 3. Remove the feature from the [labs documentation](https://github.com/vector-im/riot-web/blob/develop/docs/labs.md)
-4. Remove feature state from
-   [develop](https://github.com/vector-im/riot-web/blob/develop/riot.im/develop/config.json),
-   [nightly](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/nightly/config.json),
-   [staging / app](https://github.com/vector-im/riot-web/blob/develop/riot.im/app/config.json),
-   and
-   [release](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/release/config.json)
-   configs
-5. Celebrate! 🥳
+4. Celebrate! 🥳
 
-## Convert to a regular setting (optional)
-
-Sometimes we decide a feature should always be user-controllable as a setting
-even after it has been fully deployed. In that case, we would craft a new,
-regular setting:
-
-1. Remove the feature flag from
-   [settings](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.js)
-   and add a regular setting with the appropriate levels for your feature
-2. Replace the `isFeatureEnabled` lines with `getValue` or similar calls
-   according to the [settings
-   docs](https://github.com/matrix-org/matrix-react-sdk/blob/develop/docs/settings.md)
-   (checking carefully, as we may want a different mix of code paths when the
-   feature is always present but gated by a setting)
+If the feature is meant to be forced on (non-configurable):
+1. Remove the [setting](https://github.com/matrix-org/matrix-react-sdk/blob/develop/src/settings/Settings.ts)
+2. Remove all `getValue` lines that test for the feature.
 3. Remove the feature from the [labs documentation](https://github.com/vector-im/riot-web/blob/develop/docs/labs.md)
-4. Remove feature state from
+4. If applicable, remove the feature state from
    [develop](https://github.com/vector-im/riot-web/blob/develop/riot.im/develop/config.json),
    [nightly](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/nightly/config.json),
    [staging / app](https://github.com/vector-im/riot-web/blob/develop/riot.im/app/config.json),
    and
    [release](https://github.com/vector-im/riot-desktop/blob/develop/riot.im/release/config.json)
    configs
+5. Celebrate! 🥳