core-api: add validation of mounted route parameter uniqueness

Co-authored-by: blam <ben@blam.sh>

packages/core-api/src/routing/hooks.test.tsx

@@ -25,7 +25,7 @@ import {
 } from '../extensions/traversal';
 import { createPlugin } from '../plugin';
 import { routeCollector, routeParentCollector } from './collectors';
-import { useRouteRef, RoutingProvider } from './hooks';
+import { useRouteRef, RoutingProvider, validateRoutes } from './hooks';
 import { createRouteRef } from './RouteRef';
 import { RouteRef } from './types';
 
@@ -177,4 +177,29 @@ describe('discovery', () => {
       rendered.getByText('Path at inside: /foo/blob/baz'),
     ).toBeInTheDocument();
   });
+
+  it('should handle relative routing of parameterized routes with duplicate param names', () => {
+    const root = (
+      <MemoryRouter>
+        <Routes>
+          <Extension5 path="/foo/:id">
+            <Extension4 path="/bar/:id" name="borked" routeRef={ref4} />
+          </Extension5>
+        </Routes>
+      </MemoryRouter>
+    );
+
+    const { routes, routeParents } = traverseElementTree({
+      root,
+      discoverers: [childDiscoverer, routeElementDiscoverer],
+      collectors: {
+        routes: routeCollector,
+        routeParents: routeParentCollector,
+      },
+    });
+
+    expect(() => validateRoutes(routes, routeParents)).toThrow(
+      'Parameter :id is duplicated in path /foo/:id/bar/:id',
+    );
+  });
 });

packages/core-api/src/routing/hooks.tsx

@@ -75,3 +75,42 @@ export const RoutingProvider = ({
     </RoutingContext.Provider>
   );
 };
+
+export function validateRoutes(
+  routes: Map<RouteRef, string>,
+  routeParents: Map<RouteRef, RouteRef | undefined>,
+) {
+  const notLeafRoutes = new Set(routeParents.values());
+  notLeafRoutes.delete(undefined);
+
+  for (const route of routeParents.keys()) {
+    if (notLeafRoutes.has(route)) {
+      continue;
+    }
+
+    let currentRouteRef: RouteRef | undefined = route;
+
+    let fullPath = '';
+    while (currentRouteRef) {
+      const path = routes.get(currentRouteRef);
+      if (!path) {
+        throw new Error(`No path for ${currentRouteRef}`);
+      }
+      fullPath = `${path}${fullPath}`;
+      currentRouteRef = routeParents.get(currentRouteRef);
+    }
+
+    const params = fullPath.match(/:(\w+)/g);
+    if (params) {
+      for (let j = 0; j < params.length; j++) {
+        for (let i = j + 1; i < params.length; i++) {
+          if (params[i] === params[j]) {
+            throw new Error(
+              `Parameter ${params[i]} is duplicated in path ${fullPath}`,
+            );
+          }
+        }
+      }
+    }
+  }
+}