Upgrade ESLint et al to the latest versions (#3278)

.eslintignore

@@ -9,3 +9,4 @@ eui.d.ts
 **/assets/**/*.js
 src-docs/src/views/icon/icon_example.js
 src-framer/code/canvas.tsx
+packages/react-datepicker/examples

.eslintrc.js

@@ -68,7 +68,9 @@ module.exports = {
     "react-hooks/rules-of-hooks": "error",
     "react-hooks/exhaustive-deps": "warn",
 
-    "@typescript-eslint/array-type": ["error", "array-simple"],
+    "@typescript-eslint/array-type": ["error", { "default": "array-simple" }],
+    // Nice idea...but not today.
+    "@typescript-eslint/ban-ts-ignore": "off",
     "@typescript-eslint/camelcase": "off",
     "@typescript-eslint/class-name-casing": "off",
     "@typescript-eslint/explicit-function-return-type": "off",
@@ -81,6 +83,10 @@ module.exports = {
     "@typescript-eslint/no-triple-slash-reference": "off",
     "@typescript-eslint/no-unused-vars": ["error", { "argsIgnorePattern": "^_", "ignoreRestSiblings": true }],
     "@typescript-eslint/no-use-before-define": "off",
+    "@typescript-eslint/no-empty-function": "off",
+    // It"s all very well saying that some types are trivially inferrable,
+    // but being explicit is still clearer.
+    "@typescript-eslint/no-inferrable-types": "off",
   },
   env: {
     jest: true

package.json

@@ -96,8 +96,8 @@
     "@types/resize-observer-browser": "^0.1.1",
     "@types/tabbable": "^3.1.0",
     "@types/uuid": "^3.4.4",
-    "@typescript-eslint/eslint-plugin": "^1.13.0",
-    "@typescript-eslint/parser": "^1.13.0",
+    "@typescript-eslint/eslint-plugin": "^2.27.0",
+    "@typescript-eslint/parser": "^2.27.0",
     "autoprefixer": "^7.1.5",
     "axe-core": "^3.3.2",
     "axe-puppeteer": "^1.0.0",
@@ -128,19 +128,19 @@
     "enzyme": "^3.10.0",
     "enzyme-adapter-react-16": "^1.14.0",
     "enzyme-to-json": "^3.3.0",
-    "eslint": "^5.16.0",
-    "eslint-config-prettier": "^4.2.0",
-    "eslint-import-resolver-webpack": "^0.11.1",
+    "eslint": "^6.8.0",
+    "eslint-config-prettier": "^6.10.1",
+    "eslint-import-resolver-webpack": "^0.12.1",
     "eslint-plugin-babel": "^5.3.0",
-    "eslint-plugin-import": "^2.17.2",
-    "eslint-plugin-jest": "^22.5.1",
-    "eslint-plugin-jsx-a11y": "^6.2.1",
+    "eslint-plugin-import": "^2.20.2",
+    "eslint-plugin-jest": "^23.8.2",
+    "eslint-plugin-jsx-a11y": "^6.2.3",
     "eslint-plugin-local": "^1.0.0",
-    "eslint-plugin-mocha": "^5.3.0",
+    "eslint-plugin-mocha": "^6.3.0",
     "eslint-plugin-prefer-object-spread": "^1.2.1",
-    "eslint-plugin-prettier": "^3.1.0",
-    "eslint-plugin-react": "^7.13.0",
-    "eslint-plugin-react-hooks": "^2.0.1",
+    "eslint-plugin-prettier": "^3.1.2",
+    "eslint-plugin-react": "^7.19.0",
+    "eslint-plugin-react-hooks": "^3.0.0",
     "faker": "^4.1.0",
     "file-loader": "^1.1.11",
     "findup": "^0.1.5",

src/components/color_picker/color_stops/color_stops.tsx

@@ -77,7 +77,7 @@ function getValidStops(colorStops: ColorStop[]) {
 function getRangeMin(colorStops: ColorStop[], min?: number) {
   const rangeMin = min || DEFAULT_MIN;
   const stops = getValidStops(colorStops);
-  const first = Math.min.apply(Math, stops); // https://johnresig.com/blog/fast-javascript-maxmin/
+  const first = Math.min(...stops); // https://johnresig.com/blog/fast-javascript-maxmin/
 
   if (first < rangeMin) {
     if (stops.length === 1) {
@@ -91,7 +91,7 @@ function getRangeMin(colorStops: ColorStop[], min?: number) {
 function getRangeMax(colorStops: ColorStop[], max?: number) {
   const rangeMax = max || DEFAULT_MAX;
   const stops = getValidStops(colorStops);
-  const last = Math.max.apply(Math, stops); // https://johnresig.com/blog/fast-javascript-maxmin/
+  const last = Math.max(...stops); // https://johnresig.com/blog/fast-javascript-maxmin/
 
   if (last > rangeMax) {
     if (stops.length === 1) {

src/components/datagrid/data_grid.test.tsx

@@ -293,7 +293,7 @@ expect.extend({
   },
 });
 declare global {
-  /* eslint-disable @typescript-eslint/no-namespace */
+  /* eslint-disable-next-line @typescript-eslint/no-namespace,no-redeclare */
   namespace jest {
     interface Matchers<R> {
       toBeEuiPopover(): R;

src/components/index.d.ts

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/triple-slash-reference */
 /// <reference path="./date_picker/index.d.ts" />
 
 declare module '@elastic/eui' {

src/components/observer/resize_observer/resize_observer.test.tsx

@@ -19,7 +19,6 @@ describe('testResizeObservers', () => {
       HTMLElement.prototype.getBoundingClientRect;
     HTMLElement.prototype.getBoundingClientRect = function() {
       // use the length of the element's HTML to represent its height
-      // eslint-disable-next-line @typescript-eslint/no-object-literal-type-assertion
       return { width: 100, height: this.innerHTML.length } as ReturnType<
         GetBoundingClientRect
       >;

src/index.d.ts

@@ -1,2 +1,3 @@
+/* eslint-disable @typescript-eslint/triple-slash-reference */
 /// <reference path="./components/index.d.ts" />
 /// <reference path="./themes/index.d.ts" />