Lint rule for requiring ts-ignore descriptions

.eslintrc.js

@@ -50,66 +50,76 @@ module.exports = {
   ],
   plugins: ['jsx-a11y', 'prettier', 'local', 'react-hooks'],
   rules: {
-    "prefer-template": "error",
-    "local/i18n": "error",
-    "local/href-with-rel": "error",
-    "local/forward-ref": "error",
-    "local/require-license-header": [
+    'prefer-template': 'error',
+    'local/i18n': 'error',
+    'local/href-with-rel': 'error',
+    'local/forward-ref': 'error',
+    'local/require-license-header': [
       'warn',
       {
         license: APACHE_2_0_LICENSE_HEADER,
       },
     ],
-    "no-use-before-define": "off",
-    "quotes": ["warn", "single", "avoid-escape"],
-    "jsx-a11y/accessible-emoji": "error",
-    "jsx-a11y/alt-text": "error",
-    "jsx-a11y/anchor-has-content": "error",
-    "jsx-a11y/aria-activedescendant-has-tabindex": "error",
-    "jsx-a11y/aria-props": "error",
-    "jsx-a11y/aria-proptypes": "error",
-    "jsx-a11y/aria-role": "error",
-    "jsx-a11y/aria-unsupported-elements": "error",
-    "jsx-a11y/heading-has-content": "error",
-    "jsx-a11y/html-has-lang": "error",
-    "jsx-a11y/iframe-has-title": "error",
-    "jsx-a11y/interactive-supports-focus": "error",
-    "jsx-a11y/media-has-caption": "error",
-    "jsx-a11y/mouse-events-have-key-events": "error",
-    "jsx-a11y/no-access-key": "error",
-    "jsx-a11y/no-distracting-elements": "error",
-    "jsx-a11y/no-interactive-element-to-noninteractive-role": "error",
-    "jsx-a11y/no-noninteractive-element-interactions": "error",
-    "jsx-a11y/no-noninteractive-element-to-interactive-role": "error",
-    "jsx-a11y/no-redundant-roles": "error",
-    "jsx-a11y/role-has-required-aria-props": "error",
-    "jsx-a11y/role-supports-aria-props": "error",
-    "jsx-a11y/scope": "error",
-    "jsx-a11y/tabindex-no-positive": "error",
-    "jsx-a11y/label-has-associated-control": "error",
+    'no-use-before-define': 'off',
+    quotes: ['warn', 'single', 'avoid-escape'],
+    camelcase: 'off',
+    'jsx-a11y/accessible-emoji': 'error',
+    'jsx-a11y/alt-text': 'error',
+    'jsx-a11y/anchor-has-content': 'error',
+    'jsx-a11y/aria-activedescendant-has-tabindex': 'error',
+    'jsx-a11y/aria-props': 'error',
+    'jsx-a11y/aria-proptypes': 'error',
+    'jsx-a11y/aria-role': 'error',
+    'jsx-a11y/aria-unsupported-elements': 'error',
+    'jsx-a11y/heading-has-content': 'error',
+    'jsx-a11y/html-has-lang': 'error',
+    'jsx-a11y/iframe-has-title': 'error',
+    'jsx-a11y/interactive-supports-focus': 'error',
+    'jsx-a11y/media-has-caption': 'error',
+    'jsx-a11y/mouse-events-have-key-events': 'error',
+    'jsx-a11y/no-access-key': 'error',
+    'jsx-a11y/no-distracting-elements': 'error',
+    'jsx-a11y/no-interactive-element-to-noninteractive-role': 'error',
+    'jsx-a11y/no-noninteractive-element-interactions': 'error',
+    'jsx-a11y/no-noninteractive-element-to-interactive-role': 'error',
+    'jsx-a11y/no-redundant-roles': 'error',
+    'jsx-a11y/role-has-required-aria-props': 'error',
+    'jsx-a11y/role-supports-aria-props': 'error',
+    'jsx-a11y/scope': 'error',
+    'jsx-a11y/tabindex-no-positive': 'error',
+    'jsx-a11y/label-has-associated-control': 'error',
 
-    "react-hooks/rules-of-hooks": "error",
-    "react-hooks/exhaustive-deps": "warn",
+    'react-hooks/rules-of-hooks': 'error',
+    'react-hooks/exhaustive-deps': 'warn',
 
-    "@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",
-    "@typescript-eslint/explicit-member-accessibility": "off",
-    "@typescript-eslint/indent": "off",
-    "@typescript-eslint/no-empty-interface": "off",
-    "@typescript-eslint/no-explicit-any": "off",
-    "@typescript-eslint/no-non-null-assertion": "off",
-    "@typescript-eslint/no-parameter-properties": "off",
-    "@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",
+    '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
+    '@typescript-eslint/ban-types': 'off',
+    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/explicit-member-accessibility': 'off',
+    '@typescript-eslint/indent': 'off',
+    '@typescript-eslint/no-empty-interface': 'off',
+    '@typescript-eslint/no-explicit-any': 'off',
+    '@typescript-eslint/no-non-null-assertion': 'off',
+    '@typescript-eslint/no-parameter-properties': 'off',
+    '@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",
+    '@typescript-eslint/no-inferrable-types': 'off',
+    '@typescript-eslint/explicit-module-boundary-types': 'off',
+    '@typescript-eslint/naming-convention': 'off',
+    '@typescript-eslint/ban-ts-comment': [
+      'error',
+      {
+        'ts-ignore': 'allow-with-description',
+        'ts-expect-error': 'allow-with-description',
+      },
+    ],
   },
   env: {
     jest: true,

package.json

@@ -98,8 +98,8 @@
     "@types/resize-observer-browser": "^0.1.1",
     "@types/tabbable": "^3.1.0",
     "@types/uuid": "^3.4.4",
-    "@typescript-eslint/eslint-plugin": "^2.27.0",
-    "@typescript-eslint/parser": "^2.27.0",
+    "@typescript-eslint/eslint-plugin": "^3.2.0",
+    "@typescript-eslint/parser": "^3.2.0",
     "autoprefixer": "^7.1.5",
     "axe-core": "^3.3.2",
     "axe-puppeteer": "^1.0.0",

src-docs/src/components/with_theme/theme_context.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { EUI_THEMES, EUI_THEME } from '../../../../src/themes';
-// @ts-ignore
+// @ts-ignore importing from a JS file
 import { applyTheme } from '../../services';
 
 const defaultState = {

src-docs/src/views/color_picker/color_palette_picker.tsx

@@ -11,7 +11,7 @@ import {
   EuiColorPalettePicker,
   EuiColorPalettePickerPaletteProps,
 } from '../../../../src/components/color_picker/color_palette_picker';
-// @ts-ignore
+// @ts-ignore importing from a JS file
 import { DisplayToggles } from '../form_controls/display_toggles';
 
 const palettes: EuiColorPalettePickerPaletteProps[] = [

src-docs/src/views/header/header_stacked.tsx

@@ -8,7 +8,7 @@ import {
 import { EuiSwitch } from '../../../../src/components/form';
 import { EuiSpacer } from '../../../../src/components/spacer';
 import { EuiAvatar } from '../../../../src/components/avatar';
-// @ts-ignore
+// @ts-ignore importing from a JS file
 import HeaderUpdates from './header_updates';
 
 export default () => {

src/components/bottom_bar/bottom_bar.test.tsx

@@ -25,9 +25,8 @@ import { keysOf } from '../common';
 
 import { EuiBottomBar, paddingSizeToClassNameMap } from './bottom_bar';
 
-// TODO: Temporary hack which we can remove once react-test-renderer supports portals.
+// @ts-ignore TODO: Temporary hack which we can remove once react-test-renderer supports portals.
 // More info at https://github.com/facebook/react/issues/11565.
-// @ts-ignore
 ReactDOM.createPortal = node => node;
 
 describe('EuiBottomBar', () => {

src/components/code_editor/code_editor.test.tsx

@@ -94,7 +94,7 @@ describe('EuiCodeEditor', () => {
       test('should be enabled when the ui ace box loses focus', () => {
         const hint = findTestSubject(component, 'codeEditorHint');
         hint.simulate('keyup', { key: keys.ENTER });
-        // @ts-ignore
+        // @ts-ignore onBlurAce is known to exist and its params are only passed through to the onBlur callback
         component.instance().onBlurAce();
         expect(
           findTestSubject(component, 'codeEditorHint').getDOMNode()
@@ -106,13 +106,13 @@ describe('EuiCodeEditor', () => {
       test('bluring the ace textbox should call a passed onBlur prop', () => {
         const blurSpy = jest.fn().mockName('blurSpy');
         const el = mount(<EuiCodeEditor onBlur={blurSpy} />);
-        // @ts-ignore
+        // @ts-ignore onBlurAce is known to exist and its params are only passed through to the onBlur callback
         el.instance().onBlurAce();
         expect(blurSpy).toHaveBeenCalled();
       });
 
       test('pressing escape in ace textbox will enable overlay', () => {
-        // @ts-ignore
+        // @ts-ignore onKeydownAce is known to exist and its params' values are unimportant
         component.instance().onKeydownAce({
           preventDefault: () => {},
           stopPropagation: () => {},

src/components/color_picker/color_picker.test.tsx

@@ -25,8 +25,7 @@ import { VISUALIZATION_COLORS, keys } from '../../services';
 import { requiredProps, findTestSubject, sleep } from '../../test';
 
 jest.mock('../portal', () => ({
-  // @ts-ignore
-  EuiPortal: ({ children }) => children,
+  EuiPortal: ({ children }: { children: any }) => children,
 }));
 
 const onChange = jest.fn();

src/components/color_picker/color_stops/color_stop_thumb.test.tsx

@@ -25,8 +25,7 @@ import { EuiColorStopThumb } from './color_stop_thumb';
 import { requiredProps } from '../../../test';
 
 jest.mock('../../portal', () => ({
-  // @ts-ignore
-  EuiPortal: ({ children }) => children,
+  EuiPortal: ({ children }: { children: any }) => children,
 }));
 
 const onChange = jest.fn();

src/components/color_picker/color_stops/color_stops.test.tsx

@@ -30,8 +30,7 @@ import {
 import { requiredProps, findTestSubject } from '../../../test';
 
 jest.mock('../../portal', () => ({
-  // @ts-ignore
-  EuiPortal: ({ children }) => children,
+  EuiPortal: ({ children }: { children: any }) => children,
 }));
 
 const onChange = jest.fn();

src/components/color_picker/color_stops/utils.test.ts

@@ -42,15 +42,13 @@ describe('isInvalid', () => {
 
   test('Should mark colorStops missing stop as invalid', () => {
     const colorStops = [{ stop: null, color: '#FF0000' }];
-    // Intentionally wrong
-    // @ts-ignore
+    // @ts-ignore Intentionally wrong
     expect(isInvalid(colorStops)).toBe(true);
   });
 
   test('Should mark colorStops with invalid stop as invalid', () => {
     const colorStops = [{ stop: 'I am not a number', color: '#FF0000' }];
-    // Intentionally wrong
-    // @ts-ignore
+    // @ts-ignore Intentionally wrong
     expect(isInvalid(colorStops)).toBe(true);
   });
 });

src/components/datagrid/data_grid.test.tsx

@@ -106,7 +106,7 @@ function openColumnSorterSelection(datagrid: ReactWrapper) {
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -131,7 +131,7 @@ function closeColumnSorterSelection(datagrid: ReactWrapper) {
       .find('div[className="euiPopover__anchor"]')
       .find('[onClick]')
       .first();
-    // @ts-ignore-next-line
+    // @ts-ignore onClick is known to exist, and does not require an argument in this usage
     act(() => popoverButton.props().onClick());
 
     datagrid.update();
@@ -162,7 +162,7 @@ function getColumnSortDirection(
       `[data-test-subj="dataGridColumnSortingPopoverColumnSelection-${columnId}"]`
     );
     expect(selectColumnButton.length).toBe(1);
-    // @ts-ignore-next-line
+    // @ts-ignore onClick is known to exist, and does not require an argument in this usage
     act(() => selectColumnButton.props().onClick());
 
     // close column selection popover
@@ -200,7 +200,7 @@ function openColumnSorter(datagrid: ReactWrapper) {
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -223,7 +223,7 @@ function closeColumnSorter(datagrid: ReactWrapper) {
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -251,12 +251,8 @@ function sortByColumn(
   // if this column isn't being sorted, enable it
   if (currentSortDirection === 'off') {
     act(() => {
-      // @ts-ignore-next-line
-      columnSorter
-        .find('EuiSwitch')
-        .props()
-        // @ts-ignore-next-line
-        .onChange();
+      // @ts-ignore does not require an argument in this usage
+      columnSorter.find('EuiSwitch').props().onChange!();
     });
 
     datagrid.update();
@@ -332,7 +328,7 @@ function openColumnSelector(datagrid: ReactWrapper) {
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -355,7 +351,7 @@ function closeColumnSelector(datagrid: ReactWrapper) {
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -401,7 +397,7 @@ function moveColumnToIndex(
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();
@@ -418,7 +414,7 @@ function moveColumnToIndex(
   const portal = popover.find('EuiPortal');
   act(() =>
     portal.find('EuiDragDropContext').props().onDragEnd!({
-      // @ts-ignore-next-line - only `index` is used from `source`, don't need to mock rest of the event
+      // @ts-ignore - only `index` is used from `source`, don't need to mock rest of the event
       source: { index: initialColumnIndex },
       destination: { index: nextIndex },
     })
@@ -436,7 +432,7 @@ function moveColumnToIndex(
     .find('div[className="euiPopover__anchor"]')
     .find('[onClick]')
     .first();
-  // @ts-ignore-next-line
+  // @ts-ignore onClick is known to exist, and does not require an argument in this usage
   act(() => popoverButton.props().onClick());
 
   datagrid.update();

src/components/datagrid/data_grid_body.tsx

@@ -18,7 +18,6 @@
  */
 
 import React, { Fragment, FunctionComponent, useMemo } from 'react';
-// @ts-ignore-next-line
 import { EuiCodeBlock } from '../code';
 import {
   EuiDataGridControlColumn,

src/components/datagrid/data_grid_inmemory_renderer.tsx

@@ -50,8 +50,8 @@ function noop() {}
 function getElementText(element: HTMLElement) {
   return 'innerText' in element
     ? element.innerText
-    : // TS thinks element.innerText always exists, however it doesn't in jest/jsdom enviornment
-      // @ts-ignore-next-line
+    : // (this line left here to satisfy Prettier since a ts-ignore is used on the next line)
+      // @ts-ignore TypeScript thinks element.innerText always exists, however it doesn't in jest/jsdom enviornment
       element.textContent || undefined;
 }
 

src/components/datagrid/style_selector.tsx

@@ -20,9 +20,7 @@
 import React, { ReactElement, useState } from 'react';
 import { EuiDataGridStyle } from './data_grid_types';
 import { EuiI18n } from '../i18n';
-// @ts-ignore-next-line
 import { EuiPopover } from '../popover';
-// @ts-ignore-next-line
 import { EuiButtonEmpty, EuiButtonGroup } from '../button';
 
 export const startingStyles: EuiDataGridStyle = {