Generate globally unique common names for unnamed components, instead of falling back to "Component". Unnamed components are now rendered as <UnnamedComponent0>, where 0 is an internal ID. Two identical components (referentially equal) will render with the same name, useful for testing unnamed components.

Author: developit

src/index.js

@@ -27,6 +27,9 @@ const VOID_ELEMENTS = [
 	'wbr'
 ];
 
+// components without names, kept as a hash for later comparison to return consistent UnnamedComponentXX names.
+const UNNAMED = [];
+
 const objectKeys = Object.keys || (obj => {
 	let keys = [];
 	for (let i in obj) if (obj.hasOwnProperty(i)) keys.push(i);
@@ -163,5 +166,28 @@ export default function renderToString(vnode, context, opts, inner) {
 }
 
 function getComponentName(component) {
-	return component.displayName || component.name || component.prototype.displayName || component.prototype.name || (Function.prototype.toString.call(component).match(/\s([^\(]+)/) || EMPTY)[1] || 'Component';
+	let proto = component.prototype,
+		ctor = proto && proto.constructor;
+	return component.displayName || component.name || (proto && (proto.displayName || proto.name)) || getFallbackComponentName(component);
+}
+
+function getFallbackComponentName(component) {
+	let str = Function.prototype.toString.call(component),
+		name = (str.match(/^\s*function\s+([^\( ]+)/) || EMPTY)[1];
+	if (!name) {
+		// search for an existing indexed name for the given component:
+		let index = -1;
+		for (let i=UNNAMED.length; i--; ) {
+			if (UNNAMED[i]===component) {
+				index = i;
+				break;
+			}
+		}
+		// not found, create a new indexed name:
+		if (index<0) {
+			index = UNNAMED.push(component) - 1;
+		}
+		name = `UnnamedComponent${index}`;
+	}
+	return name;
 }