Enable noImplictThis rule

tsconfig.base.json

@@ -14,6 +14,7 @@
     "lib": ["dom", "dom.iterable", "esnext"],
     "jsx": "react-jsx",
     "strictBindCallApply": true,
+    "noImplicitThis": true,
     "noEmitHelpers": true,
     "resolveJsonModule": true,
     "skipLibCheck": true,

web/packages/shared/utils/highbar.test.ts

@@ -16,7 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-import { arrayObjectIsEqual, equalsDeep, mergeDeep } from './highbar';
+import { arrayObjectIsEqual, equalsDeep, mergeDeep, runOnce } from './highbar';
 
 describe('mergeDeep can merge two', () => {
   it('objects together', () => {
@@ -368,3 +368,26 @@ describe('equalsDeep', () => {
     ).toBe(false);
   });
 });
+
+test('runOnce only runs once and preserves "this"', () => {
+  class Counter {
+    count = 0;
+
+    increment = runOnce(
+      // Use 'this' in a convoluted way to make sure it's passed correctly.
+      function (this: Counter) {
+        this.count++;
+      }
+    );
+  }
+
+  const c = new Counter();
+
+  // First call increments (and doesn't throw because of 'this' being undefined).
+  expect(() => c.increment()).not.toThrow();
+  expect(c.count).toBe(1);
+
+  // Subsequent calls do not increment.
+  c.increment();
+  expect(c.count).toBe(1);
+});

web/packages/shared/utils/highbar.ts

@@ -133,22 +133,18 @@ export function isObject(checkVal: unknown): checkVal is object {
   return checkVal != null && (type == 'object' || type == 'function');
 }
 
-/**
- * Lodash <https://lodash.com/>
- * Copyright JS Foundation and other contributors <https://js.foundation/>
- * Released under MIT license <https://lodash.com/license>
- * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
- * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
- */
-export function runOnce<T extends (...args) => any>(func: T) {
-  let n = 2;
-  let result;
-  return function () {
-    if (--n > 0) {
-      // This implementation does not pass strictBindCallApply check.
-      result = func.apply(this, arguments as any);
-    }
-    if (n <= 1) {
+/** Runs the provided function only once. */
+export function runOnce<T extends (...args: any[]) => any>(func: T) {
+  let hasRun = false;
+  let result: ReturnType<T>;
+
+  // 'this' is a special TS parameter that is erased during compilation
+  // https://www.typescriptlang.org/docs/handbook/2/classes.html#this-parameters
+  return function (this: unknown, ...args: Parameters<T>) {
+    if (!hasRun) {
+      hasRun = true;
+      result = func.apply(this, args);
+      // Remove the reference, so it can be garbage-collected.
       func = undefined;
     }
     return result;
@@ -305,7 +301,7 @@ export function debounce<T extends (...args: any) => any>(
     return timerId === undefined ? result : trailingEdge(Date.now());
   }
 
-  function debounced() {
+  function debounced(this: unknown) {
     var time = Date.now(),
       isInvoking = shouldInvoke(time);
 
@@ -333,167 +329,3 @@ export function debounce<T extends (...args: any) => any>(
   debounced.flush = flush;
   return debounced;
 }
-
-interface MapCacheType {
-  delete(key: any): boolean;
-  get(key: any): any;
-  has(key: any): boolean;
-  set(key: any, value: any): this;
-  clear?: (() => void) | undefined;
-}
-
-type MemoizedFunction = {
-  cache: MapCacheType;
-};
-
-/**
- * Lodash <https://lodash.com/>
- * Copyright JS Foundation and other contributors <https://js.foundation/>
- * Released under MIT license <https://lodash.com/license>
- * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
- * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
- */
-export function memoize<T extends (...args: any) => any>(
-  func: T
-): T & MemoizedFunction {
-  const memoized = function () {
-    const args = arguments;
-    const key = args[0];
-    const cache = memoized.cache;
-
-    if (cache.has(key)) {
-      return cache.get(key);
-    }
-    // `as any` because the implementation does not pass strictBindCallApply check.
-    const result = func.apply(this, args as any);
-    memoized.cache = cache.set(key, result) || cache;
-    return result;
-  };
-  memoized.cache = new (memoize.Cache || MapCache)();
-  /* eslint-disable @typescript-eslint/ban-ts-comment*/
-  // @ts-ignore
-  return memoized;
-}
-
-// Expose `MapCache`.
-memoize.Cache = MapCache;
-
-function MapCache(entries?: any) {
-  let index = -1;
-  const length = entries == null ? 0 : entries.length;
-
-  this.clear();
-  while (++index < length) {
-    const entry = entries[index];
-    this.set(entry[0], entry[1]);
-  }
-}
-
-function mapCacheClear() {
-  this.size = 0;
-  this.__data__ = {
-    hash: new Hash(),
-    map: new Map(),
-    string: new Hash(),
-  };
-}
-
-function mapCacheDelete(key) {
-  var result = getMapData(this, key)['delete'](key);
-  this.size -= result ? 1 : 0;
-  return result;
-}
-
-function mapCacheGet(key) {
-  return getMapData(this, key).get(key);
-}
-
-function mapCacheHas(key) {
-  return getMapData(this, key).has(key);
-}
-
-function mapCacheSet(key, value) {
-  var data = getMapData(this, key),
-    size = data.size;
-
-  data.set(key, value);
-  this.size += data.size == size ? 0 : 1;
-  return this;
-}
-
-MapCache.prototype.clear = mapCacheClear;
-MapCache.prototype['delete'] = mapCacheDelete;
-MapCache.prototype.get = mapCacheGet;
-MapCache.prototype.has = mapCacheHas;
-MapCache.prototype.set = mapCacheSet;
-
-function Hash(entries?) {
-  var index = -1,
-    length = entries == null ? 0 : entries.length;
-
-  this.clear();
-  while (++index < length) {
-    var entry = entries[index];
-    this.set(entry[0], entry[1]);
-  }
-}
-
-const HASH_UNDEFINED = '__lodash_hash_undefined__';
-
-function hashClear() {
-  this.__data__ = Object.create ? Object.create(null) : {};
-  this.size = 0;
-}
-
-function hashDelete(key) {
-  var result = this.has(key) && delete this.__data__[key];
-  this.size -= result ? 1 : 0;
-  return result;
-}
-
-function hashGet(key) {
-  var data = this.__data__;
-  if (Object.create) {
-    var result = data[key];
-    return result === HASH_UNDEFINED ? undefined : result;
-  }
-  return Object.hasOwnProperty.call(data, key) ? data[key] : undefined;
-}
-
-function hashHas(key) {
-  var data = this.__data__;
-  return Object.create
-    ? data[key] !== undefined
-    : Object.hasOwnProperty.call(data, key);
-}
-
-function hashSet(key, value) {
-  var data = this.__data__;
-  this.size += this.has(key) ? 0 : 1;
-  data[key] = Object.create && value === undefined ? HASH_UNDEFINED : value;
-  return this;
-}
-
-// Add methods to `Hash`.
-Hash.prototype.clear = hashClear;
-Hash.prototype['delete'] = hashDelete;
-Hash.prototype.get = hashGet;
-Hash.prototype.has = hashHas;
-Hash.prototype.set = hashSet;
-
-function getMapData(map, key) {
-  var data = map.__data__;
-  return isKeyable(key)
-    ? data[typeof key == 'string' ? 'string' : 'hash']
-    : data.map;
-}
-
-function isKeyable(value) {
-  var type = typeof value;
-  return type == 'string' ||
-    type == 'number' ||
-    type == 'symbol' ||
-    type == 'boolean'
-    ? value !== '__proto__'
-    : value === null;
-}

web/packages/teleport/src/services/websession/websession.ts

@@ -35,6 +35,10 @@ const logger = Logger.create('services/session');
 let sesstionCheckerTimerId = null;
 
 const session = {
+  _isRenewing: false,
+  _isDeviceTrustRequired: false,
+  _isDeviceTrusted: false,
+
   logout(rememberLocation = false) {
     let samlSloUrl = '';
 
@@ -204,29 +208,29 @@ const session = {
       });
   },
 
-  _setAndBroadcastIsRenewing(value) {
+  _setAndBroadcastIsRenewing(value: boolean) {
     this._setIsRenewing(value);
     storageService.broadcast(KeysEnum.TOKEN_RENEW, value);
   },
 
-  _setIsRenewing(value) {
+  _setIsRenewing(value: boolean) {
     this._isRenewing = value;
   },
 
   _getIsRenewing() {
-    return !!this._isRenewing;
+    return this._isRenewing;
   },
 
   setDeviceTrustRequired() {
     this._isDeviceTrustRequired = true;
   },
 
   getDeviceTrustRequired() {
-    return !!this._isDeviceTrustRequired;
+    return this._isDeviceTrustRequired;
   },
 
   getIsDeviceTrusted() {
-    return !!this._isDeviceTrusted;
+    return this._isDeviceTrusted;
   },
 
   // a session will never be "downgraded" so we can just set to true

web/packages/teleterm/src/services/pty/ptyHost/resolveShellEnv.ts

@@ -44,15 +44,19 @@
 
 import { spawn } from 'child_process';
 
-import { memoize } from 'shared/utils/highbar';
-
 import Logger from 'teleterm/logger';
 import { unique } from 'teleterm/ui/utils/uid';
 
-const logger = new Logger('resolveShellEnv()');
+const logger = new Logger('resolveShellEnv');
 const resolveShellMaxTime = 10_000; // 10s
 
-export const resolveShellEnvCached = memoize(resolveShellEnv);
+const cache = new Map<string, Promise<typeof process.env | undefined>>();
+export function resolveShellEnvCached(shell: string) {
+  if (!cache.has(shell)) {
+    cache.set(shell, resolveShellEnv(shell));
+  }
+  return cache.get(shell);
+}
 
 export class ResolveShellEnvTimeoutError extends Error {}
 

web/packages/teleterm/src/ui/DocumentTerminal/useDocumentTerminal.ts

@@ -189,9 +189,6 @@ async function setUpPtyProcess(
     refreshTitle();
   });
 
-  // TODO(ravicious): Refactor runOnce to not use the `n` variable. Otherwise runOnce subtracts 1
-  // from n each time the resulting function is executed, which in this context means each time data
-  // is transferred from PTY.
   const markDocumentAsConnectedOnce = runOnce(() => {
     if ('status' in doc) {
       documentsService.update(doc.uri, { status: 'connected' });