manual annotations in preparation of natural inference rollout in react-native, tools, etc.

Summary:
The Flow team is improving the way Flow infers type for primitive literals. This diff prepares the codebase for the new behavior by adding type annotations, or annotations of the form `'abc' as const`.

Changelog: [internal]

Reviewed By: marcoww6

Differential Revision: D75188179

fbshipit-source-id: be50990f23f79cf2d8dae7576af5190218adcafe

Author: panagosg7

packages/react-native-babel-transformer/src/index.js

@@ -188,7 +188,7 @@ const transform /*: BabelTransformer['transform'] */ = ({
     : process.env.BABEL_ENV || 'production';
 
   try {
-    const babelConfig = {
+    const babelConfig /*: BabelCoreOptions */ = {
       // ES modules require sourceType='module' but OSS may not always want that
       sourceType: 'unambiguous',
       ...buildBabelConfig(filename, options, plugins),

packages/react-native-compatibility-check/src/VersionDiffing.js

@@ -976,14 +976,14 @@ function buildNativeModulesDiff(
     objectTypeChanges,
   );
 
-  const newType = {
+  const newType: CompleteTypeAnnotation = {
     type: 'ObjectTypeAnnotation',
     properties: [
       ...newerNativeModule.spec.methods,
       ...newerNativeModule.spec.eventEmitters,
     ],
   };
-  const oldType = {
+  const oldType: CompleteTypeAnnotation = {
     type: 'ObjectTypeAnnotation',
     properties: [
       ...olderNativeModule.spec.methods,
@@ -1073,11 +1073,11 @@ function buildNativeComponentsDiff(
           olderCommand => olderCommand.name === command.name,
         );
 
-        const newCommands = {
+        const newCommands: CompleteTypeAnnotation = {
           type: 'ObjectTypeAnnotation',
           properties: [command],
         };
-        const oldCommands =
+        const oldCommands: ?CompleteTypeAnnotation =
           oldCommand != null
             ? {
                 type: 'ObjectTypeAnnotation',
@@ -1123,15 +1123,15 @@ function buildNativeComponentsDiff(
 
       // We have to do this to remove the .defaults from the props and get it into
       // standard JavaScript shapes.
-      const newConvertedProps = {
+      const newConvertedProps: CompleteTypeAnnotation = {
         type: 'ObjectTypeAnnotation',
         properties: newerComponent.props.map(prop => ({
           name: prop.name,
           optional: prop.optional,
           typeAnnotation: convertPropToBasicTypes(prop.typeAnnotation),
         })),
       };
-      const oldConvertedProps = {
+      const oldConvertedProps: CompleteTypeAnnotation = {
         type: 'ObjectTypeAnnotation',
         properties: olderComponent.props.map(prop => ({
           name: prop.name,

packages/react-native-fantom/runner/runner.js

@@ -9,7 +9,11 @@
  */
 
 import type {TestSuiteResult} from '../runtime/setup';
-import type {AsyncCommandResult, HermesVariant} from './utils';
+import type {
+  AsyncCommandResult,
+  ConsoleLogMessage,
+  HermesVariant,
+} from './utils';
 
 import entrypointTemplate from './entrypoint-template';
 import * as EnvironmentOptions from './EnvironmentOptions';
@@ -69,7 +73,7 @@ async function processRNTesterCommandResult(
       return;
     }
 
-    let parsed;
+    let parsed: ConsoleLogMessage;
     try {
       parsed = JSON.parse(line);
     } catch {

packages/react-native-fantom/runtime/setup.js

@@ -320,7 +320,7 @@ function runSpec(spec: Spec): TestCaseResult {
     return result;
   }
 
-  let status;
+  let status: 'passed' | 'failed' | 'pending';
   let error;
 
   const start = Date.now();

packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js

@@ -30,7 +30,7 @@ import nullthrows from 'nullthrows';
 import * as React from 'react';
 import {createRef} from 'react';
 
-const DRAWER_STATES = ['Idle', 'Dragging', 'Settling'];
+const DRAWER_STATES = ['Idle', 'Dragging', 'Settling'] as const;
 
 /**
  * React component that wraps the platform `DrawerLayout` (Android only). The

packages/react-native/Libraries/Components/ScrollView/ScrollView.js

@@ -1646,7 +1646,9 @@ class ScrollView extends React.Component<ScrollViewProps, ScrollViewState> {
     if (__DEV__ && this.props.style !== undefined) {
       // $FlowFixMe[underconstrained-implicit-instantiation]
       const style = flattenStyle(this.props.style);
-      const childLayoutProps = ['alignItems', 'justifyContent'].filter(
+      const childLayoutProps = (
+        ['alignItems', 'justifyContent'] as const
+      ).filter(
         // $FlowFixMe[incompatible-use]
         prop => style && style[prop] !== undefined,
       );

packages/react-native/Libraries/Components/Touchable/TouchableWithoutFeedback.js

@@ -152,7 +152,7 @@ const PASSTHROUGH_PROPS = [
   'onFocus',
   'onLayout',
   'testID',
-];
+] as const;
 
 /**
  * Do not use unless you have a very good reason.

packages/react-native/Libraries/Core/setUpDeveloperTools.js

@@ -23,17 +23,19 @@ if (__DEV__) {
     // TODO(T214991636): Remove legacy Metro log forwarding
     if (console._isPolyfilled) {
       // We assume full control over the console and send JavaScript logs to Metro.
-      [
-        'trace',
-        'info',
-        'warn',
-        'error',
-        'log',
-        'group',
-        'groupCollapsed',
-        'groupEnd',
-        'debug',
-      ].forEach(level => {
+      (
+        [
+          'trace',
+          'info',
+          'warn',
+          'error',
+          'log',
+          'group',
+          'groupCollapsed',
+          'groupEnd',
+          'debug',
+        ] as const
+      ).forEach(level => {
         const originalFunction = console[level];
         console[level] = function (...args: $ReadOnlyArray<mixed>) {
           HMRClient.log(level, args);

packages/react-native/Libraries/Text/Text.js

@@ -545,6 +545,6 @@ const verticalAlignToTextAlignVerticalMap = {
   top: 'top',
   bottom: 'bottom',
   middle: 'center',
-};
+} as const;
 
 export default TextImpl;

packages/react-native/scripts/ios-prebuild/hermes.js

@@ -97,10 +97,10 @@ type HermesEngineSourceType =
 */
 
 const HermesEngineSourceTypes = {
-  LOCAL_PREBUILT_TARBALL: 'local_prebuilt_tarball',
-  DOWNLOAD_PREBUILD_TARBALL: 'download_prebuild_tarball',
-  DOWNLOAD_PREBUILT_NIGHTLY_TARBALL: 'download_prebuilt_nightly_tarball',
-};
+    LOCAL_PREBUILT_TARBALL: 'local_prebuilt_tarball',
+    DOWNLOAD_PREBUILD_TARBALL: 'download_prebuild_tarball',
+    DOWNLOAD_PREBUILT_NIGHTLY_TARBALL: 'download_prebuilt_nightly_tarball',
+  } /*:: as const */;
 
 /**
  * Checks if the Hermes artifacts are already downloaded and up to date with the specified version.