Changes the behavior of initial loading state.

src/__tests__/use-script.test.tsx

@@ -155,4 +155,20 @@ describe('useScript', () => {
 
         expect(document.querySelectorAll('script').length).toBe(0);
     });
+
+    it('should NOT set loading to true if checkForExisting finds the script', () => {
+        expect(document.querySelectorAll('script').length).toBe(0);
+
+        const previousScript = document.createElement('script');
+        previousScript.src = 'http://scriptsrc/';
+        document.body.appendChild(previousScript);
+
+        expect(document.querySelectorAll('script').length).toBe(1);
+
+        const props = { src: 'http://scriptsrc/', checkForExisting: true };
+        const { result } = renderHook(() => useScript(props));
+        const [loading] = result.all[0] as Array<any>;
+        expect(loading).toEqual(false);
+        expect(document.querySelectorAll('script').length).toBe(1);
+    });
 });

src/use-script.tsx

@@ -13,7 +13,8 @@ export default function useScript({
     checkForExisting = false,
     ...attributes
 }: ScriptProps): [boolean, ErrorState] {
-    const [loading, setLoading] = useState(Boolean(src));
+    const initialLoadingState = checkForExisting ? false : Boolean(src);
+    const [loading, setLoading] = useState(initialLoadingState);
     const [error, setError] = useState<ErrorState>(null);
 
     useEffect(() => {
@@ -24,6 +25,8 @@ export default function useScript({
             if (existing.length > 0) {
                 setLoading(false);
                 return;
+            } else {
+                setLoading(true);
             }
         }