[5.0.3] Provider with multiple children makes renderToString return <undefined/>

[johannesodland]

If a provider has multiple children then the result of a render is an array of VNodes. RenderToString tries to fetch the nodeName of this array on line 180: s = `<${nodeName}${s}>`; . The result is the string <undefined>.

This breaks server side rendering of valid Preact applications.

const TestContext = createContext();
function TestComponent() {
   
   return <TestContext.Provider>
      <div>1</div>
      <div>2</div>
   </TestContext.Provider>
}

Preact 10.0.0-beta.2 handles this case by coercing the array to a fragment:

	if (Array.isArray(possibleVNode)) {
		return createElement(Fragment, null, possibleVNode);
	}

Maybe preact-render-to-string should coerce the render result to vnodes too?

[andrewiggins]

Hi @johannesodland ! Thanks for filing an issue 😄 Looks like #96 fixes this one. Let us know if you find any other bugs.