From 7d30365c67795ac27b50d558793360ff0a176d75 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Tue, 9 Mar 2021 12:19:32 +0100
Subject: [PATCH] core-api: migrate RoutingContext to use version bridge

Co-authored-by: Juan Lulkin <jmaiz@spotify.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 packages/core-api/src/routing/hooks.test.tsx | 65 +++++++++++++++++++-
 packages/core-api/src/routing/hooks.tsx      | 34 ++++++++--
 2 files changed, 91 insertions(+), 8 deletions(-)

diff --git a/packages/core-api/src/routing/hooks.test.tsx b/packages/core-api/src/routing/hooks.test.tsx
index 9a65286fd6..d16f9808ab 100644
--- a/packages/core-api/src/routing/hooks.test.tsx
+++ b/packages/core-api/src/routing/hooks.test.tsx
@@ -14,9 +14,17 @@
  * limitations under the License.
  */
 
-import { render } from '@testing-library/react';
-import React, { PropsWithChildren, ReactElement } from 'react';
+import React, {
+  PropsWithChildren,
+  ReactElement,
+  useContext,
+  Context,
+} from 'react';
 import { MemoryRouter, Routes } from 'react-router-dom';
+import { render } from '@testing-library/react';
+import { renderHook } from '@testing-library/react-hooks';
+import { VersionedValue } from '../lib/versionedValues';
+import { getGlobalSingleton } from '../lib/globalObject';
 import { createRoutableExtension } from '../extensions';
 import {
   childDiscoverer,
@@ -32,6 +40,7 @@ import {
 import { validateRoutes } from './validation';
 import { useRouteRef, RoutingProvider } from './hooks';
 import { createRouteRef, RouteRefConfig } from './RouteRef';
+import { RouteResolver } from './RouteResolver';
 import { createExternalRouteRef } from './ExternalRouteRef';
 import { AnyRouteRef, RouteFunc, RouteRef, ExternalRouteRef } from './types';
 
@@ -309,3 +318,55 @@ describe('discovery', () => {
     );
   });
 });
+
+describe('v1 consumer', () => {
+  const RoutingContext = getGlobalSingleton<
+    Context<VersionedValue<{ 1: RouteResolver }>>
+  >('routing-context');
+
+  function useMockRouteRefV1(
+    routeRef: AnyRouteRef,
+    location: string,
+  ): RouteFunc<any> | undefined {
+    const resolver = useContext(RoutingContext)?.atVersion(1);
+    if (!resolver) {
+      throw new Error('no impl');
+    }
+    return resolver.resolve(routeRef, location);
+  }
+
+  it('should resolve routes', () => {
+    const routeRef1 = createRouteRef({ id: 'ref1' });
+    const routeRef2 = createRouteRef({ id: 'ref2' });
+    const routeRef3 = createRouteRef({ id: 'ref3', params: ['x'] });
+
+    const renderedHook = renderHook(
+      ({ routeRef }) => useMockRouteRefV1(routeRef, '/'),
+      {
+        initialProps: {
+          routeRef: routeRef1 as AnyRouteRef,
+        },
+        wrapper: ({ children }) => (
+          <RoutingProvider
+            routePaths={
+              new Map<RouteRef<any>, string>([
+                [routeRef2, '/foo'],
+                [routeRef3, '/bar/:x'],
+              ])
+            }
+            routeParents={new Map()}
+            routeObjects={[]}
+            routeBindings={new Map()}
+            children={children}
+          />
+        ),
+      },
+    );
+
+    expect(renderedHook.result.current).toBe(undefined);
+    renderedHook.rerender({ routeRef: routeRef2 });
+    expect(renderedHook.result.current?.()).toBe('/foo');
+    renderedHook.rerender({ routeRef: routeRef3 });
+    expect(renderedHook.result.current?.({ x: 'my-x' })).toBe('/bar/my-x');
+  });
+});
diff --git a/packages/core-api/src/routing/hooks.tsx b/packages/core-api/src/routing/hooks.tsx
index 2e65efaba6..b8690d867a 100644
--- a/packages/core-api/src/routing/hooks.tsx
+++ b/packages/core-api/src/routing/hooks.tsx
@@ -14,7 +14,13 @@
  * limitations under the License.
  */
 
-import React, { createContext, ReactNode, useContext, useMemo } from 'react';
+import React, {
+  createContext,
+  ReactNode,
+  useContext,
+  useMemo,
+  Context,
+} from 'react';
 import { useLocation } from 'react-router-dom';
 import {
   BackstageRouteObject,
@@ -25,8 +31,16 @@ import {
   RouteFunc,
 } from './types';
 import { RouteResolver } from './RouteResolver';
+import {
+  VersionedValue,
+  createVersionedValueMap,
+} from '../lib/versionedValues';
+import { setGlobalSingleton, getGlobalSingleton } from '../lib/globalObject';
 
-const RoutingContext = createContext<RouteResolver | undefined>(undefined);
+type RoutingContextType = VersionedValue<{ 1: RouteResolver }> | undefined;
+const RoutingContext = createContext<RoutingContextType>(undefined);
+
+setGlobalSingleton('routing-context', RoutingContext);
 
 export function useRouteRef<Optional extends boolean, Params extends AnyParams>(
   routeRef: ExternalRouteRef<Params, Optional>,
@@ -41,14 +55,20 @@ export function useRouteRef<Params extends AnyParams>(
     | ExternalRouteRef<Params, any>,
 ): RouteFunc<Params> | undefined {
   const sourceLocation = useLocation();
-  const resolver = useContext(RoutingContext);
+  const versionedContext = useContext(
+    getGlobalSingleton<Context<RoutingContextType>>('routing-context'),
+  );
+  const resolver = versionedContext?.atVersion(1);
   const routeFunc = useMemo(
     () => resolver && resolver.resolve(routeRef, sourceLocation),
     [resolver, routeRef, sourceLocation],
   );
 
-  if (!routeFunc && !resolver) {
-    throw new Error('No route resolver found in context');
+  if (!versionedContext) {
+    throw new Error('useRouteRef used outside of routing context');
+  }
+  if (!resolver) {
+    throw new Error('RoutingContext v1 not available');
   }
 
   const isOptional = 'optional' in routeRef && routeRef.optional;
@@ -80,8 +100,10 @@ export const RoutingProvider = ({
     routeObjects,
     routeBindings,
   );
+
+  const versionedValue = createVersionedValueMap({ 1: resolver });
   return (
-    <RoutingContext.Provider value={resolver}>
+    <RoutingContext.Provider value={versionedValue}>
       {children}
     </RoutingContext.Provider>
   );