Upgrade eslint + flow

package.json

@@ -53,17 +53,16 @@
     "cross-env": "^6.0.3",
     "del": "^5.1.0",
     "es6-shim": "^0.35.5",
-    "eslint": "^6.6.0",
+    "eslint": "^6.8.0",
     "eslint-config-fbjs": "^3.1.1",
-    "eslint-config-prettier": "^6.5.0",
+    "eslint-config-prettier": "^6.9.0",
     "eslint-plugin-babel": "^5.3.0",
-    "eslint-plugin-flowtype": "^4.3.0",
+    "eslint-plugin-flowtype": "^4.6.0",
     "eslint-plugin-jsx-a11y": "^6.2.3",
-    "eslint-plugin-prettier": "^3.1.1",
-    "eslint-plugin-react": "^7.16.0",
-    "eslint-plugin-relay": "^1.3.12",
+    "eslint-plugin-prettier": "^3.1.2",
+    "eslint-plugin-react": "^7.17.0",
     "fbjs-scripts": "^1.2.0",
-    "flow-bin": "^0.110.1",
+    "flow-bin": "^0.115.0",
     "gulp": "^4.0.2",
     "gulp-babel": "^8.0.0",
     "gulp-clean-css": "^4.2.0",

scripts/jest/preprocessor.js

@@ -15,6 +15,10 @@ module.exports = {
   process(src, filename) {
     var options = {
       presets: [fbjsConfigurePreset({rewriteModules: {map: moduleMap}})],
+      plugins: [
+        require('@babel/plugin-proposal-nullish-coalescing-operator'),
+        require('@babel/plugin-proposal-optional-chaining')
+      ],
       filename: filename,
       retainLines: true,
     };

src/.flowconfig

@@ -50,4 +50,4 @@ unsafe-getters-setters
 ; nonstrict-import
 
 [version]
-^0.110.1
+^0.115.0

src/component/handlers/edit/editOnBlur.js

@@ -29,6 +29,8 @@ function editOnBlur(editor: DraftEditor, e: SyntheticEvent<HTMLElement>): void {
   // opposed to clicking to another tab or window).
   const {ownerDocument} = e.currentTarget;
   if (
+    // This ESLint rule conflicts with `sketchy-null-bool` flow check
+    // eslint-disable-next-line no-extra-boolean-cast
     !Boolean(editor.props.preserveSelectionOnBlur) &&
     getActiveElement(ownerDocument) === ownerDocument.body
   ) {