Prototype/propsoal: Implement controller messaging proposal

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "typescript.tsdk": "node_modules/typescript/lib"
+}

package.json

@@ -65,6 +65,7 @@
     "@types/jest": "^22.2.3",
     "@types/node": "^10.1.4",
     "@types/sinon": "^4.3.3",
+    "@types/uuid": "^8.3.0",
     "@types/web3": "^1.0.6",
     "@typescript-eslint/eslint-plugin": "^4.1.0",
     "@typescript-eslint/parser": "^4.1.0",
@@ -80,7 +81,7 @@
     "sinon": "^7.4.1",
     "ts-jest": "^26.3.0",
     "typedoc": "^0.15.0",
-    "typescript": "^4.0.3"
+    "typescript": "^4.1.3"
   },
   "jest": {
     "moduleFileExtensions": [

src/ComposableController.ts

@@ -65,6 +65,7 @@ export class ComposableController extends BaseController<any, any> {
       const { name } = controller;
       this.context[name] = controller;
       controller.context = this.context;
+      controller.messagingSystem = this.messagingSystem;
       this.cachedState && this.cachedState[name] && controller.update(this.cachedState[name]);
       initialState[name] = controller.state;
       controller.subscribe((state) => {

src/MSG-SYSTEM.ts

@@ -0,0 +1,18 @@
+import { EventEmitter } from 'events';
+
+interface AttenuatedMessageSystem {
+  subscriptionIds: string[];
+  call: () => void;
+}
+
+export function attenuatedMessageSystem(
+  eventEmitter: EventEmitter,
+  actionMap: Map<string, any>,
+  allowedActions: string[],
+  allowedSubscriptions: string[]
+): AttenuatedMessageSystem {
+  return Object.freeze({
+    subscriptionIds: [],
+    call: () => {},
+  });
+}

src/assets/AccountTrackerController.ts

@@ -1,5 +1,6 @@
 import BaseController, { BaseConfig, BaseState } from '../BaseController';
-import PreferencesController from '../user/PreferencesController';
+import { ControllerMessagingSystem } from '../controller-messaging-system';
+import { GET_PREFERENCES_STATE, PREFERENCES_STATE_CHANGED } from '../user/PreferencesController';
 import { BNToHex, safelyExecute } from '../util';
 
 const EthjsQuery = require('ethjs-query');
@@ -44,12 +45,14 @@ export interface AccountTrackerState extends BaseState {
 export class AccountTrackerController extends BaseController<AccountTrackerConfig, AccountTrackerState> {
   private ethjsQuery: any;
 
+  private messagingSystem: ControllerMessagingSystem;
+
   private handle?: NodeJS.Timer;
 
   private syncAccounts() {
     const {
-      state: { identities },
-    } = this.context.PreferencesController as PreferencesController;
+      identities,
+    } = this.messagingSystem.call(GET_PREFERENCES_STATE);
     const { accounts } = this.state;
     const addresses = Object.keys(identities);
     const existing = Object.keys(accounts);
@@ -69,19 +72,15 @@ export class AccountTrackerController extends BaseController<AccountTrackerConfi
    */
   name = 'AccountTrackerController';
 
-  /**
-   * List of required sibling controllers this controller needs to function
-   */
-  requiredControllers = ['PreferencesController'];
-
   /**
    * Creates an AccountTracker instance
    *
    * @param config - Initial options used to configure this controller
    * @param state - Initial state to set on this controller
    */
-  constructor(config?: Partial<AccountTrackerConfig>, state?: Partial<AccountTrackerState>) {
+  constructor(messagingSystem: ControllerMessagingSystem, config?: Partial<AccountTrackerConfig>, state?: Partial<AccountTrackerState>) {
     super(config, state);
+    this.messagingSystem = messagingSystem;
     this.defaultConfig = {
       interval: 10000,
     };
@@ -104,8 +103,7 @@ export class AccountTrackerController extends BaseController<AccountTrackerConfi
    */
   onComposed() {
     super.onComposed();
-    const preferences = this.context.PreferencesController as PreferencesController;
-    preferences.subscribe(this.refresh);
+    this.messagingSystem.subscribe(PREFERENCES_STATE_CHANGED, this.refresh);
     this.poll();
   }
 

src/assets/AssetsController.ts

@@ -1,9 +1,10 @@
 import { EventEmitter } from 'events';
 import { toChecksumAddress } from 'ethereumjs-util';
 import BaseController, { BaseConfig, BaseState } from '../BaseController';
-import PreferencesController from '../user/PreferencesController';
+import { PreferencesState, PREFERENCES_STATE_CHANGED } from '../user/PreferencesController';
 import NetworkController, { NetworkType } from '../network/NetworkController';
 import { safelyExecute, handleFetch, validateTokenToWatch } from '../util';
+import { ControllerMessagingSystem } from '../controller-messaging-system';
 import { Token } from './TokenRatesController';
 import { AssetsContractController } from './AssetsContractController';
 import { ApiCollectibleResponse } from './AssetsDetectionController';
@@ -166,6 +167,10 @@ export interface AssetsState extends BaseState {
 export class AssetsController extends BaseController<AssetsConfig, AssetsState> {
   private mutex = new Mutex();
 
+  private messagingSystem: ControllerMessagingSystem;
+
+  private preferencesSubId?: string;
+
   private getCollectibleApi(contractAddress: string, tokenId: number) {
     return `https://api.opensea.io/api/v1/asset/${contractAddress}/${tokenId}`;
   }
@@ -515,16 +520,17 @@ export class AssetsController extends BaseController<AssetsConfig, AssetsState>
   /**
    * List of required sibling controllers this controller needs to function
    */
-  requiredControllers = ['AssetsContractController', 'NetworkController', 'PreferencesController'];
+  requiredControllers = ['AssetsContractController', 'NetworkController'];
 
   /**
    * Creates a AssetsController instance
    *
    * @param config - Initial options used to configure this controller
    * @param state - Initial state to set on this controller
    */
-  constructor(config?: Partial<BaseConfig>, state?: Partial<AssetsState>) {
+  constructor(messagingSystem: ControllerMessagingSystem, config?: Partial<BaseConfig>, state?: Partial<AssetsState>) {
     super(config, state);
+    this.messagingSystem = messagingSystem;
     this.defaultConfig = {
       networkType: 'mainnet',
       selectedAddress: '',
@@ -795,9 +801,8 @@ export class AssetsController extends BaseController<AssetsConfig, AssetsState>
    */
   onComposed() {
     super.onComposed();
-    const preferences = this.context.PreferencesController as PreferencesController;
     const network = this.context.NetworkController as NetworkController;
-    preferences.subscribe(({ selectedAddress }) => {
+    this.preferencesSubId = this.messagingSystem.subscribe<PreferencesState>(PREFERENCES_STATE_CHANGED, ({ selectedAddress }) => {
       const { allCollectibleContracts, allCollectibles, allTokens } = this.state;
       const { networkType } = this.config;
       this.configure({ selectedAddress });
@@ -821,6 +826,12 @@ export class AssetsController extends BaseController<AssetsConfig, AssetsState>
       });
     });
   }
+
+  onDestroy() {
+    if (this.preferencesSubId) {
+      this.messagingSystem.unsubscribe(this.preferencesSubId);
+    }
+  }
 }
 
 export default AssetsController;

src/assets/AssetsDetectionController.ts

@@ -1,8 +1,9 @@
 import { toChecksumAddress } from 'ethereumjs-util';
 import BaseController, { BaseConfig, BaseState } from '../BaseController';
 import NetworkController, { NetworkType } from '../network/NetworkController';
-import PreferencesController from '../user/PreferencesController';
+import { PreferencesState, PREFERENCES_STATE_CHANGED } from '../user/PreferencesController';
 import { safelyExecute, timeoutFetch } from '../util';
+import { ControllerMessagingSystem } from '../controller-messaging-system';
 import AssetsContractController from './AssetsContractController';
 import { Token } from './TokenRatesController';
 
@@ -55,6 +56,10 @@ export interface AssetsDetectionConfig extends BaseConfig {
 export class AssetsDetectionController extends BaseController<AssetsDetectionConfig, BaseState> {
   private handle?: NodeJS.Timer;
 
+  private messagingSystem: ControllerMessagingSystem;
+
+  private subId?: string;
+
   private getOwnerCollectiblesApi(address: string) {
     return `https://api.opensea.io/api/v1/assets?owner=${address}&limit=300`;
   }
@@ -88,16 +93,17 @@ export class AssetsDetectionController extends BaseController<AssetsDetectionCon
   /**
    * List of required sibling controllers this controller needs to function
    */
-  requiredControllers = ['AssetsContractController', 'AssetsController', 'NetworkController', 'PreferencesController'];
+  requiredControllers = ['AssetsContractController', 'AssetsController', 'NetworkController'];
 
   /**
    * Creates a AssetsDetectionController instance
    *
    * @param config - Initial options used to configure this controller
    * @param state - Initial state to set on this controller
    */
-  constructor(config?: Partial<AssetsDetectionConfig>, state?: Partial<BaseState>) {
+  constructor(messagingSystem: ControllerMessagingSystem, config?: Partial<AssetsDetectionConfig>, state?: Partial<BaseState>) {
     super(config, state);
+    this.messagingSystem = messagingSystem;
     this.defaultConfig = {
       interval: DEFAULT_INTERVAL,
       networkType: 'mainnet',
@@ -256,23 +262,30 @@ export class AssetsDetectionController extends BaseController<AssetsDetectionCon
    */
   onComposed() {
     super.onComposed();
-    const preferences = this.context.PreferencesController as PreferencesController;
     const network = this.context.NetworkController as NetworkController;
     const assets = this.context.AssetsController as AssetsController;
     assets.subscribe(({ tokens }) => {
       this.configure({ tokens });
     });
-    preferences.subscribe(({ selectedAddress }) => {
+
+    this.subId = this.messagingSystem.subscribe<PreferencesState>(PREFERENCES_STATE_CHANGED, ({ selectedAddress }) => {
       const actualSelectedAddress = this.config.selectedAddress;
       if (selectedAddress !== actualSelectedAddress) {
         this.configure({ selectedAddress });
         this.detectAssets();
       }
     });
+
     network.subscribe(({ provider }) => {
       this.configure({ networkType: provider.type });
     });
   }
+
+  onDestroyed() {
+    if (this.subId) {
+      this.messagingSystem.unsubscribe(this.subId);
+    }
+  }
 }
 
 export default AssetsDetectionController;

src/assets/CurrencyRateController.ts

@@ -3,6 +3,7 @@ import { Mutex } from 'await-semaphore';
 import BaseController from '../base-controller-v2';
 import { safelyExecute } from '../util';
 import { fetchExchangeRate as defaultFetchExchangeRate } from '../crypto-compare';
+import { ControllerMessagingSystem } from '../controller-messaging-system';
 
 /**
  * @type CurrencyRateState
@@ -35,11 +36,28 @@ const schema = {
   usdConversionRate: { persist: false, anonymous: true },
 };
 
+/** constants */
+const GET_CURRENCY_RATE_STATE = 'CurrencyRateController.getState';
+const SET_CURRENT_CURRENCY = 'CurrencyRateController.setCurrentCurrency';
+const SET_NATIVE_CURRENCY = 'CurrencyRateController.setNativeCurrency';
+
+export const CURRENCY_RATE_STATE_CHANGED = 'CurrencyRateController.state-changed';
+
+export interface CurrencyRateActions {
+  [GET_CURRENCY_RATE_STATE]: () => CurrencyRateState;
+  [SET_CURRENT_CURRENCY]: (currentCurrency: string) => void;
+  [SET_NATIVE_CURRENCY]: (nativeCurrency: string) => void;
+}
+
+export interface CurrencyRateEvents {
+  [CURRENCY_RATE_STATE_CHANGED]: CurrencyRateState;
+}
+
 /**
  * Controller that passively polls on a set interval for an exchange rate from the current base
  * asset to the current currency
  */
-export class CurrencyRateController extends BaseController<CurrencyRateState> {
+export class CurrencyRateController extends BaseController<CurrencyRateState, CurrencyRateActions> {
 
   private static defaultState = {
     conversionDate: 0,
@@ -65,11 +83,16 @@ export class CurrencyRateController extends BaseController<CurrencyRateState> {
    *
    * @param state - Initial state to set on this controller
    */
-  constructor(state?: Partial<CurrencyRateState>, includeUsdRate = false, fetchExchangeRate = defaultFetchExchangeRate) {
-    super({ ...CurrencyRateController.defaultState, ...state }, schema);
+  constructor(messagingSystem: ControllerMessagingSystem, state?: Partial<CurrencyRateState>, includeUsdRate = false, fetchExchangeRate = defaultFetchExchangeRate) {
+    super(messagingSystem, { ...CurrencyRateController.defaultState, ...state }, CURRENCY_RATE_STATE_CHANGED, schema);
     this.includeUsdRate = includeUsdRate;
     this.fetchExchangeRate = fetchExchangeRate;
     this.poll();
+    this.registerActions({
+      [GET_CURRENCY_RATE_STATE]: () => this.state,
+      [SET_CURRENT_CURRENCY]: this.setCurrentCurrency,
+      [SET_NATIVE_CURRENCY]: this.setNativeCurrency,
+    });
   }
 
   destroy() {

src/assets/TokenRatesController.ts

@@ -1,6 +1,9 @@
 import { toChecksumAddress } from 'ethereumjs-util';
 import BaseController, { BaseConfig, BaseState } from '../BaseController';
+import { ControllerMessagingSystem } from '../controller-messaging-system';
 import { safelyExecute, handleFetch } from '../util';
+import AssetsController from './AssetsController';
+import { CURRENCY_RATE_STATE_CHANGED, CurrencyRateState } from './CurrencyRateController';
 
 /**
  * @type CoinGeckoResponse
@@ -63,6 +66,10 @@ export interface TokenRatesState extends BaseState {
 export class TokenRatesController extends BaseController<TokenRatesConfig, TokenRatesState> {
   private handle?: NodeJS.Timer;
 
+  private messagingSystem: ControllerMessagingSystem;
+
+  private subId?: string;
+
   private tokenList: Token[] = [];
 
   private getPricingURL(query: string) {
@@ -77,16 +84,17 @@ export class TokenRatesController extends BaseController<TokenRatesConfig, Token
   /**
    * List of required sibling controllers this controller needs to function
    */
-  requiredControllers = ['AssetsController', 'CurrencyRateController'];
+  requiredControllers = ['AssetsController'];
 
   /**
    * Creates a TokenRatesController instance
    *
    * @param config - Initial options used to configure this controller
    * @param state - Initial state to set on this controller
    */
-  constructor(config?: Partial<TokenRatesConfig>, state?: Partial<TokenRatesState>) {
+  constructor(messagingSystem: ControllerMessagingSystem, config?: Partial<TokenRatesConfig>, state?: Partial<TokenRatesState>) {
     super(config, state);
+    this.messagingSystem = messagingSystem;
     this.defaultConfig = {
       disabled: true,
       interval: 180000,
@@ -133,6 +141,27 @@ export class TokenRatesController extends BaseController<TokenRatesConfig, Token
     return handleFetch(this.getPricingURL(query));
   }
 
+    /**
+   * Extension point called if and when this controller is composed
+   * with other controllers using a ComposableController
+   */
+  onComposed() {
+    super.onComposed();
+    const assets = this.context.AssetsController as AssetsController;
+    assets.subscribe(() => {
+      this.configure({ tokens: assets.state.tokens });
+    });
+    this.subId = this.messagingSystem.subscribe<CurrencyRateState>(CURRENCY_RATE_STATE_CHANGED, (state) => {
+      this.configure({ nativeCurrency: state.nativeCurrency });
+    });
+  }
+
+  onDestroyed() {
+    if (this.subId) {
+      this.messagingSystem.unsubscribe(this.subId);
+    }
+  }
+
   /**
    * Updates exchange rates for all tokens
    *