Explicitly define return type

packages/redux-devtools-inspector-monitor/src/ActionList.tsx

@@ -18,6 +18,7 @@ import {
   verticalListSortingStrategy,
 } from '@dnd-kit/sortable';
 import { CSS } from '@dnd-kit/utilities';
+import type { JSX } from '@emotion/react/jsx-runtime';
 import ActionListRow from './ActionListRow';
 import ActionListHeader from './ActionListHeader';
 
@@ -80,7 +81,7 @@ export default function ActionList<A extends Action<string>>({
   onJumpToState,
   lastActionId,
   onReorderAction,
-}: Props<A>) {
+}: Props<A>): JSX.Element {
   const nodeRef = useRef<HTMLDivElement | null>(null);
   const prevLastActionId = useRef<number | undefined>();
 

packages/redux-devtools-inspector-monitor/src/ActionListRow.tsx

@@ -4,6 +4,7 @@ import type { DebouncedFunc } from 'lodash';
 import debounce from 'lodash.debounce';
 import { Action } from 'redux';
 import type { Interpolation, Theme } from '@emotion/react';
+import type { JSX } from '@emotion/react/jsx-runtime';
 import RightSlider from './RightSlider';
 import {
   selectorButtonCss,
@@ -52,7 +53,7 @@ export default class ActionListRow<
 > extends PureComponent<Props<A>, State> {
   state: State = { hover: false };
 
-  render() {
+  render(): JSX.Element {
     const {
       isSelected,
       action,

packages/redux-devtools-inspector-monitor/src/ActionPreview.tsx

@@ -4,6 +4,7 @@ import { Action } from 'redux';
 import type { LabelRenderer } from 'react-json-tree';
 import { PerformAction } from '@redux-devtools/core';
 import { Delta } from 'jsondiffpatch';
+import type { JSX } from '@emotion/react/jsx-runtime';
 import { DEFAULT_STATE, DevtoolsInspectorState } from './redux';
 import ActionPreviewHeader from './ActionPreviewHeader';
 import DiffTab from './tabs/DiffTab';
@@ -80,7 +81,7 @@ class ActionPreview<S, A extends Action<string>> extends Component<
     tabName: DEFAULT_STATE.tabName,
   };
 
-  render() {
+  render(): JSX.Element {
     const {
       delta,
       error,

packages/redux-devtools-inspector-monitor/src/tabs/JSONDiff.tsx

@@ -6,6 +6,7 @@ import { Delta } from 'jsondiffpatch';
 import { Base16Theme } from 'redux-devtools-themes';
 import { css } from '@emotion/react';
 import type { Interpolation, Theme } from '@emotion/react';
+import type { JSX } from '@emotion/react/jsx-runtime';
 import getItemString from './getItemString';
 import getJsonTreeTheme from './getJsonTreeTheme';
 
@@ -91,7 +92,7 @@ export default class JSONDiff extends Component<Props, State> {
     this.setState({ data: this.props.delta });
   }
 
-  render() {
+  render(): JSX.Element {
     const { base16Theme, ...props } = this.props;
 
     if (!this.state.data) {

packages/redux-devtools-inspector-monitor/src/tabs/getItemString.tsx

@@ -1,5 +1,6 @@
 import React from 'react';
 import { isCollection, isIndexed, isKeyed } from 'immutable';
+import type { JSX } from '@emotion/react/jsx-runtime';
 import isIterable from '../utils/isIterable';
 
 const IS_IMMUTABLE_KEY = '@@__IS_IMMUTABLE__@@';
@@ -76,7 +77,7 @@ const getItemString = (
   dataTypeKey: string | symbol | undefined,
   isWideLayout: boolean,
   isDiff?: boolean,
-) => (
+): JSX.Element => (
   <span css={(theme) => ({ color: theme.ITEM_HINT_COLOR })}>
     {data[IS_IMMUTABLE_KEY] ? 'Immutable' : ''}
     {dataTypeKey && data[dataTypeKey] ? `${data[dataTypeKey] as string} ` : ''}