feat(STX-331): migrate STX flags to smart-transactions-controller (#550)

Author: rarquevaux

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- **BREAKING**: The controller now reads feature flags directly from `RemoteFeatureFlagController` via the messenger instead of using the `getFeatureFlags` callback
+  - Clients must configure the following as allowed actions in the controller messenger:
+    - `RemoteFeatureFlagController:getState`
+    - `ErrorReportingService:captureException` (for reporting validation errors to Sentry)
+  - Clients must configure `RemoteFeatureFlagController:stateChange` as an allowed event
+  - The `getFeatureFlags` constructor option is now deprecated and ignored
+
 ## [21.1.0]
 
 ### Added

README.md

@@ -25,6 +25,53 @@ Run `yarn test` to run the tests once. To run tests on file changes, run `yarn t
 
 Run `yarn lint` to run the linter, or run `yarn lint:fix` to run the linter and fix any automatically fixable issues.
 
+### Feature Flags
+
+Smart transactions feature flags are managed via `RemoteFeatureFlagController` (LaunchDarkly). The configuration uses a `default` remote object for global settings and chain-specific overrides keyed by hex chain ID.
+
+The flag in LaunchDarkly is named `smartTransactionsNetworks`.
+
+#### Adding a New Flag
+
+1. **Add the field to the schema** in `src/utils/validators.ts`:
+
+   ```typescript
+   export const SmartTransactionsNetworkConfigSchema = type({
+     // ... existing fields
+     myNewFlag: optional(boolean()),
+   });
+   ```
+
+   The `SmartTransactionsNetworkConfig` type is automatically inferred from this schema.
+
+2. **Add default value** in `src/constants.ts` under `DEFAULT_DISABLED_SMART_TRANSACTIONS_FEATURE_FLAGS`:
+
+   These values should be defensive. They are applied when the remote config is invalid or does not exist for a network.
+   It disables smart transaction.
+
+   ```typescript
+   export const DEFAULT_DISABLED_SMART_TRANSACTIONS_FEATURE_FLAGS = {
+     default: {
+       // ... existing defaults
+       myNewFlag: false,
+     },
+   };
+   ```
+
+3. **Use in clients** via the exported selectors:
+
+   ```typescript
+   import { selectSmartTransactionsFeatureFlagsForChain } from '@metamask/smart-transactions-controller';
+
+   const chainConfig = selectSmartTransactionsFeatureFlagsForChain(
+     state,
+     '0x1',
+   );
+   if (chainConfig.myNewFlag) {
+     // Feature is enabled
+   }
+   ```
+
 ### Release & Publishing
 
 The project follows the same release process as the other libraries in the MetaMask organization. The GitHub Actions [`action-create-release-pr`](https://github.com/MetaMask/action-create-release-pr) and [`action-publish-release`](https://github.com/MetaMask/action-publish-release) are used to automate the release process; see those repositories for more information about how they work.

package.json

@@ -51,22 +51,27 @@
     "@metamask/eth-query": "^4.0.0",
     "@metamask/messenger": "^0.3.0",
     "@metamask/polling-controller": "^15.0.0",
+    "@metamask/superstruct": "^3.1.0",
+    "@metamask/utils": "^11.0.0",
     "bignumber.js": "^9.0.1",
     "fast-json-patch": "^3.1.0",
-    "lodash": "^4.17.21"
+    "lodash": "^4.17.21",
+    "reselect": "^5.1.1"
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "^0.18.2",
     "@lavamoat/allow-scripts": "^3.2.1",
     "@lavamoat/preinstall-always-fail": "^2.1.0",
     "@metamask/auto-changelog": "^3.1.0",
+    "@metamask/error-reporting-service": "^3.0.0",
     "@metamask/eslint-config": "^12.2.0",
     "@metamask/eslint-config-jest": "^12.1.0",
     "@metamask/eslint-config-nodejs": "^12.1.0",
     "@metamask/eslint-config-typescript": "^12.1.0",
     "@metamask/gas-fee-controller": "^22.0.0",
     "@metamask/json-rpc-engine": "^10.0.1",
     "@metamask/network-controller": "^25.0.0",
+    "@metamask/remote-feature-flag-controller": "^2.0.0",
     "@metamask/transaction-controller": "^61.0.0",
     "@ts-bridge/cli": "^0.6.3",
     "@types/jest": "^26.0.24",
@@ -93,7 +98,9 @@
     "typescript": "~4.8.4"
   },
   "peerDependencies": {
+    "@metamask/error-reporting-service": "^3.0.0",
     "@metamask/network-controller": "^25.0.0",
+    "@metamask/remote-feature-flag-controller": "^2.0.0",
     "@metamask/transaction-controller": "^61.0.0"
   },
   "peerDependenciesMeta": {
@@ -108,9 +115,6 @@
     },
     "@metamask/gas-fee-controller": {
       "optional": true
-    },
-    "@metamask/remote-feature-flag-controller": {
-      "optional": true
     }
   },
   "packageManager": "yarn@3.2.1",