upgrade dev tools to flow 0.241 and fix sample app

Summary:
Problem: the Relay repo is in flow `0.241` while the devtools are in `0.113.0` this means that if we use relay 17 in this project we will get a bunch of flow errors.

Additionally, all the nice features for react like component syntax and hook syntax are missing. To fix this I'm doing a least effort upgrade, fixing easy and repeatable patterns first and using `$FlowFixMe` for the rest.

Changes:
1. Explicit return types: used the codemods in this [note](https://medium.com/flow-type/local-type-inference-for-flow-aaa65d071347) and manually added the react component return types. For context, portal and fragments I just used FlowFixMe
2. Using objects as maps: Devtools uses objects as maps extensively, replaced those with FlowFixMe and we can move them to proper maps iteratively.
3. Bridge: Bridge had input and output types inferred, but they aren't used. Replaced with any.
4. Removed dead files: `Observable.js`, `isPromise.js` aren't required and had lots of errors, removing them was easier than upgrading.

It's a massive diff, but most changes are `FlowFixMe`'s.

To fix the sample app, I stringyfied and and parsed the store in the dev backend. We already do this for the chrome extension.

Reviewed By: tyao1

Differential Revision: D60495796

fbshipit-source-id: f5ddd5220015cb25adbf6c0fc3d84d8583118a39

.flowconfig

@@ -9,20 +9,19 @@ shells/dev/build/*
 [include]
 
 [libs]
-/flow-typed/
 ./flow.js
 
 [lints]
 
 [options]
-esproposal.class_instance_fields=enable
-suppress_comment=\\(.\\|\n\\)*\\$FlowFixMe
-suppress_comment=\\(.\\|\n\\)*\\$FlowIssue
-suppress_comment=\\(.\\|\n\\)*\\$FlowIgnore
 module.name_mapper='^src' ->'<PROJECT_ROOT>/src'
-esproposal.optional_chaining=enable
+suppress_type=$FlowIssue
+suppress_type=$FlowFixMe
+suppress_type=$FlowFixMeProps
+suppress_type=$FlowFixMeState
+suppress_type=$FlowExpectedError
 
 [strict]
 
 [version]
-^0.113.0
+^0.241.0

flow-typed/jest.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-type JestMockFn<TArguments: $ReadOnlyArray<*>, TReturn> = {
+type JestMockFn<TArguments: $ReadOnlyArray<mixed>, TReturn> = {
   (...args: TArguments): TReturn,
   /**
    * An object for introspecting mock calls
@@ -620,7 +620,7 @@ interface JestExpectType {
    * Use .toBeInstanceOf(Class) to check that an object is an instance of a
    * class.
    */
-  toBeInstanceOf(cls: Class<*>): void;
+  toBeInstanceOf(cls: Class<mixed>): void;
   /**
    * .toBeNull() is the same as .toBe(null) but the error messages are a bit
    * nicer.
@@ -811,7 +811,7 @@ type JestObjectType = {
    * Returns a new, unused mock function. Optionally takes a mock
    * implementation.
    */
-  fn<TArguments: $ReadOnlyArray<*>, TReturn>(
+  fn<TArguments: $ReadOnlyArray<mixed>, TReturn>(
     implementation?: (...args: TArguments) => TReturn
   ): JestMockFn<TArguments, TReturn>,
   /**

package.json

@@ -115,7 +115,7 @@
     "eslint-plugin-react-hooks": "^2.2.0",
     "events": "^3.0.0",
     "firefox-profile": "^1.0.2",
-    "flow-bin": "^0.113.0",
+    "flow-bin": "^0.241.0",
     "fs-extra": "^3.0.1",
     "graphql": "^16.9.0",
     "jest": "^24.9.0",

packages/relay-devtools-core/src/backend.js

@@ -28,7 +28,7 @@ installHook(window);
 
 const hook: DevToolsHook = window.__RELAY_DEVTOOLS_HOOK__;
 
-function debug(methodName: string, ...args) {
+function debug(methodName: string, ...args: [] | [any] | [string] | [Array<WallEvent>]) {
   if (__DEBUG__) {
     console.log(
       `%c[core/backend] %c${methodName}`,
@@ -40,12 +40,7 @@ function debug(methodName: string, ...args) {
 }
 
 export function connectToDevTools(options: ?ConnectOptions) {
-  const {
-    host = 'localhost',
-    port = 8097,
-    websocket,
-    isAppActive = () => true,
-  } = options || {};
+  const {host = 'localhost', port = 8097, websocket, isAppActive = () => true} = options || {};
 
   let retryTimeoutID: TimeoutID | null = null;
 
@@ -140,7 +135,7 @@ export function connectToDevTools(options: ?ConnectOptions) {
     scheduleRetry();
   }
 
-  function handleMessage(event) {
+  function handleMessage(event: any | MessageEvent) {
     let data;
     try {
       if (typeof event.data === 'string') {

packages/relay-devtools-core/src/launchEditor.js

@@ -155,7 +155,7 @@ export default function launchEditor(
     args.push(filePath);
   }
 
-  if (childProcess && isTerminalEditor(editor)) {
+  if (isTerminalEditor(editor) && childProcess) {
     // There's an existing editor process already and it's attached
     // to the terminal, so go kill it. Otherwise two separate editor
     // instances attach to the stdin/stdout which gets confusing.
@@ -171,8 +171,9 @@ export default function launchEditor(
   } else {
     childProcess = spawn(editor, args, { stdio: 'inherit' });
   }
-  childProcess.on('error', function() {});
-  childProcess.on('exit', function(errorCode) {
+  const cp = childProcess;
+  cp.on('error', function() {});
+  cp.on('exit', function(errorCode) {
     childProcess = null;
   });
 }

packages/relay-devtools/app.js

@@ -13,7 +13,7 @@ const argv = require('minimist')(process.argv.slice(2));
 const projectRoots = argv._;
 const defaultThemeName = argv.theme;
 
-let mainWindow = null;
+let mainWindow: null | typeof BrowserWindow = null;
 
 app.on('window-all-closed', function() {
   app.quit();
@@ -31,26 +31,27 @@ app.on('ready', function() {
       nodeIntegration: true,
     },
   });
+  const mw = mainWindow;
 
   // and load the index.html of the app.
-  mainWindow.loadURL('file://' + __dirname + '/app.html'); // eslint-disable-line no-path-concat
-  mainWindow.webContents.executeJavaScript(
+  mw.loadURL('file://' + __dirname + '/app.html'); // eslint-disable-line no-path-concat
+  mw.webContents.executeJavaScript(
     // We use this so that RN can keep relative JSX __source filenames
     // but "click to open in editor" still works. js1 passes project roots
     // as the argument to DevTools.
     'window.devtools.setProjectRoots(' + JSON.stringify(projectRoots) + ')'
   );
 
   if (argv.theme) {
-    mainWindow.webContents.executeJavaScript(
+    mw.webContents.executeJavaScript(
       'window.devtools.setDefaultThemeName(' +
         JSON.stringify(defaultThemeName) +
         ')'
     );
   }
 
   // Emitted when the window is closed.
-  mainWindow.on('closed', function() {
+  mw.on('closed', function() {
     mainWindow = null;
   });
 });

shells/browser/shared/src/backend.js

@@ -11,7 +11,7 @@
 // Running module factories is intentionally delayed until we know the hook exists.
 // This is to avoid issues like: https://github.com/facebook/react-devtools/issues/1039
 
-function welcome(event) {
+function welcome(event: any) {
   if (
     event.source !== window ||
     event.data.source !== 'relay-devtools-content-script'
@@ -26,14 +26,14 @@ function welcome(event) {
 
 window.addEventListener('message', welcome);
 
-function setup(hook) {
+function setup(hook: any) {
   const Agent = require('src/backend/agent').default;
   const Bridge = require('src/bridge').default;
   const { initBackend } = require('src/backend');
 
-  const bridge = new Bridge({
+  const bridge = new Bridge<any, any>({
     listen(fn) {
-      const listener = event => {
+      const listener = (event: any) => {
         if (
           event.source !== window ||
           !event.data ||

shells/browser/shared/src/background.js

@@ -9,7 +9,7 @@
 
 /* global chrome */
 
-const ports = {};
+const ports: $FlowFixMe = {};
 
 const IS_FIREFOX = navigator.userAgent.indexOf('Firefox') >= 0;
 
@@ -50,13 +50,13 @@ function installContentScript(tabId: number) {
   );
 }
 
-function doublePipe(one, two) {
+function doublePipe(one: any, two: any) {
   one.onMessage.addListener(lOne);
-  function lOne(message) {
+  function lOne(message: any) {
     two.postMessage(message);
   }
   two.onMessage.addListener(lTwo);
-  function lTwo(message) {
+  function lTwo(message: any) {
     one.postMessage(message);
   }
   function shutdown() {
@@ -69,7 +69,7 @@ function doublePipe(one, two) {
   two.onDisconnect.addListener(shutdown);
 }
 
-function setIconAndPopup(relayBuildType, tabId) {
+function setIconAndPopup(relayBuildType: string, tabId: number) {
   chrome.browserAction.setIcon({
     tabId: tabId,
     path: {

shells/browser/shared/src/contentScript.js

@@ -22,7 +22,7 @@ function sayHelloToBackend() {
   );
 }
 
-function handleMessageFromDevtools(message) {
+function handleMessageFromDevtools(message: any) {
   window.postMessage(
     {
       source: 'relay-devtools-content-script',
@@ -32,7 +32,7 @@ function handleMessageFromDevtools(message) {
   );
 }
 
-function handleMessageFromPage(evt) {
+function handleMessageFromPage(evt: any) {
   if (
     evt.source === window &&
     evt.data &&
@@ -76,7 +76,7 @@ sayHelloToBackend();
 // In the event of a page reload, the content script might be loaded before the backend is injected.
 // Because of this we need to poll the backend until it has been initialized.
 if (!backendInitialized) {
-  const intervalID = setInterval(() => {
+  const intervalID: IntervalID = setInterval(() => {
     if (backendInitialized || backendDisconnected) {
       clearInterval(intervalID);
     } else {

shells/browser/shared/src/injectGlobalHook.js

@@ -13,7 +13,7 @@
 import nullthrows from 'nullthrows';
 import { installHook } from 'src/hook';
 
-function injectCode(code) {
+function injectCode(code: string) {
   const script = document.createElement('script');
   script.textContent = code;
 

shells/dev/relay-app/FriendsList/App.js

@@ -13,7 +13,7 @@ import { graphql, QueryRenderer } from 'react-relay';
 import createInBrowserNetwork from './createInBrowserNetwork';
 import Friends from './Friends';
 
-function createNewEnvironment(configName) {
+function createNewEnvironment(configName: string) {
   const source = new RecordSource();
   const store = new Store(source);
   var environment = new Environment({
@@ -37,7 +37,7 @@ export type Item = {|
 
 type Props = {||};
 
-export default function App(props: Props) {
+export default function App(props: Props): React$MixedElement {
   // Add initial environment to environmentList
   const [environmentList, updateEnvironmentList] = useState({
     'Example Environment': initialEnvironment,
@@ -53,12 +53,12 @@ export default function App(props: Props) {
 
     updateEnvironmentList({
       ...environmentList,
-      [newEnvironment.configName]: newEnvironment,
+      [(newEnvironment.configName: $FlowFixMe)]: newEnvironment,
     });
   }, [environmentList]);
 
   const selectNewEnvironment = useCallback(
-    e => {
+    (e: any) => {
       setCurrentEnvironment(environmentList[e.target.value]);
     },
     [environmentList]

shells/dev/relay-app/FriendsList/FriendCard.js

@@ -10,13 +10,13 @@
 import React from 'react';
 import { graphql, createFragmentContainer } from 'react-relay';
 import styles from './FriendCard.css';
-import type { FriendCard_user } from './__generated__/FriendCard_user.graphql';
+import type { FriendCard_user$data } from './__generated__/FriendCard_user.graphql';
 
 type Props = {|
-  +user: FriendCard_user,
+  +user: FriendCard_user$data,
 |};
 
-export default createFragmentContainer(
+export default (createFragmentContainer(
   function FriendCard(props: Props) {
     return (
       <div className={styles.Card}>
@@ -39,4 +39,4 @@ export default createFragmentContainer(
       }
     `,
   }
-);
+): $FlowFixMe);

shells/dev/relay-app/FriendsList/Friends.js

@@ -11,15 +11,15 @@ import React, { Fragment } from 'react';
 import { graphql, createPaginationContainer } from 'react-relay';
 import FriendCard from './FriendCard';
 import styles from './Friends.css';
-import type { Friends_user } from './__generated__/Friends_user.graphql';
-import type { RelayProps } from 'react-relay';
+import type { Friends_user$data } from './__generated__/Friends_user.graphql';
+import type { $RelayProps } from 'react-relay';
 
 type Props = {|
-  +user: Friends_user,
-  +relay: RelayProps,
+  +user: Friends_user$data,
+  +relay: $RelayProps<any>,
 |};
 
-export default createPaginationContainer(
+export default (createPaginationContainer(
   function Friends(props: Props) {
     const edges = Array.isArray(props.user.friends?.edges)
       ? props.user.friends?.edges
@@ -92,4 +92,4 @@ export default createPaginationContainer(
       }
     `,
   }
-);
+): $FlowFixMe);