Add prop type validation

package.json

@@ -4,7 +4,10 @@
   "description": "In development. React multi-search autocomplete component.",
   "author": "Tom Southall",
   "keywords": [],
-  "files": ["dist", "README.md"],
+  "files": [
+    "dist",
+    "README.md"
+  ],
   "main": "./dist/turnstone.umd.js",
   "module": "./dist/turnstone.es.js",
   "exports": {
@@ -20,23 +23,31 @@
   },
   "dependencies": {
     "first-of-type": "^1.0.0",
+    "prop-types": "^15.8.1",
     "react-use": "^17.3.2",
     "setify": "^1.0.4",
     "swr": "^1.1.2",
     "use-debounce": "^7.0.1"
   },
   "devDependencies": {
+    "@vitejs/plugin-react": "^1.0.7",
+    "eslint": "^8.9.0",
+    "eslint-plugin-react": "^7.28.0",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
-    "@vitejs/plugin-react": "^1.0.7",
     "vite": "^2.8.0"
   },
   "eslintConfig": {
+    "env": {
+      "es6": true
+    },
     "extends": [
       "eslint:recommended",
-      "react-app",
-      "react-app/jest"
-    ]
+      "plugin:react/recommended"
+    ],
+    "parserOptions": {
+      "sourceType": "module"
+    }
   },
   "browserslist": {
     "production": [
@@ -50,4 +61,4 @@
       "last 1 safari version"
     ]
   }
-}
+}

src/App.jsx

@@ -17,5 +17,3 @@ const App = () => {
 }
 
 export default App
-
-

src/lib/index.jsx

@@ -1,5 +1,7 @@
 import React from 'react'
+import PropTypes from 'prop-types'
 import { TurnstoneContextProvider } from './context/turnstone'
+import isUndefined from './utils/isUndefined'
 import AutocompleteInput from './components/input'
 
 export default function Turnstone(props) {
@@ -13,3 +15,63 @@ export default function Turnstone(props) {
     </TurnstoneContextProvider>
   )
 }
+
+//////////////////////////////////////////////////////
+// Prop validation //
+//////////////////////////////////////////////////////
+
+const msgBothRequired = `Either a "data" prop or an "itemGroups" prop must be provided. Both are missing.`
+const msgOneOnly = `Both a "data" prop and an "itemGroups" prop were provided. Provide one only.`
+const requiredPropsAreMissing = (props) => isUndefined(props.data) && isUndefined(props.itemGroups)
+Turnstone.propTypes = {
+  autoFocus: PropTypes.bool,
+  data: (props) => {
+    if(requiredPropsAreMissing(props)) return new Error(msgBothRequired)
+    if(!isUndefined(props.data) && !isUndefined(props.itemGroups)) return new Error(msgOneOnly)
+    PropTypes.checkPropTypes(
+      {data: PropTypes.oneOfType([PropTypes.array, PropTypes.func])},
+      {data: props.data},
+      'prop', 'Turnstone'
+    )
+  },
+  dataSearchType: PropTypes.oneOf(['startswith', 'contains']),
+  debounceWait: PropTypes.number,
+  defaultItemGroups: PropTypes.array,
+  defaultItemGroupsAreImmutable: PropTypes.bool,
+  displayField: PropTypes.oneOfType([PropTypes.number, PropTypes.string]),
+  itemGroups: (props) => {
+    if(requiredPropsAreMissing(props)) return new Error(msgBothRequired)
+    if(!isUndefined(props.data) && !isUndefined(props.itemGroups)) return new Error(msgOneOnly)
+    PropTypes.checkPropTypes(
+      {
+        itemGroups: PropTypes.arrayOf(PropTypes.exact({
+          name: PropTypes.string.isRequired,
+          data: PropTypes.oneOfType([
+            PropTypes.func,
+            PropTypes.array
+          ]).isRequired,
+          dataSearchType: PropTypes.oneOf(['startswith', 'contains']),
+          displayField: PropTypes.string,
+          ratio: PropTypes.number
+        }))
+      },
+      {itemGroups: props.itemGroups},
+      'prop', 'Turnstone'
+    )
+  },
+  itemGroupsAreImmutable: PropTypes.bool,
+  loadingMessage: PropTypes.string,
+  minQueryLength: PropTypes.number,
+  noItemsMessage: PropTypes.string,
+  onChange: PropTypes.func,
+  onSelect: PropTypes.func,
+  onEnter: PropTypes.func,
+  onTab: PropTypes.func,
+  placeholder: PropTypes.string,
+  maxItems: PropTypes.number,
+  splitChar: PropTypes.string,
+  styles: PropTypes.object,
+  text: PropTypes.string
+}
+
+//////////////////////////////////////////////////////