Fix issues while mocking graphs in tests (#134)

Fix issues while mocking graphs in tests

This PR fixes two issues that happened only while mocking graphs:

1. Requiring a singleton graph before it was mocked resulted in Obsidian always using the original graph instead of the mock
2. Obsidian's graph registry, which is intended to be a singleton, was instantiated multiple times. Apparently this was caused by issues with Jest/Node compatibility

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-obsidian",
-  "version": "2.2.0",
+  "version": "2.3.0-rc.1",
   "description": "Dependency injection framework for React and React Native applications",
   "scripts": {
     "prepack": "npm run lint && tsc --project tsconfig.prod.json",
@@ -53,7 +53,7 @@
     "eslint-plugin-local-rules": "^1.3.2",
     "eslint-plugin-react": "^7.26.1",
     "eslint-plugin-react-hooks": "^4.2.0",
-    "eslint-plugin-unused-imports": "2.x.x",
+    "eslint-plugin-unused-imports": "3.1.x",
     "husky": "8.0.1",
     "jest": "29.5.x",
     "jest-create-mock-instance": "2.0.0",

src/graph/registry/GraphRegistry.ts

@@ -70,6 +70,22 @@ export class GraphRegistry {
     return Reflect.getMetadata('isLifecycleBound', Graph) ?? false;
   }
 
+  clearGraphAfterItWasMockedInTests(graphName: string) {
+    const graphNames = this.nameToInstance.keys();
+    for (const name of graphNames) {
+      if (name.match(graphName)) {
+        const graph = this.nameToInstance.get(name);
+        if (!graph) return;
+        const Graph = this.instanceToConstructor.get(graph);
+        if (!Graph) return;
+
+        this.instanceToConstructor.delete(graph);
+        this.constructorToInstance.get(Graph)!.delete(graph);
+        this.nameToInstance.delete(graph.name);
+      }
+    }
+  }
+
   clear(graph: Graph) {
     const Graph = this.instanceToConstructor.get(graph);
     if (!Graph || this.isSingleton(Graph)) return;
@@ -93,4 +109,7 @@ export class GraphRegistry {
   }
 }
 
-export default new GraphRegistry();
+// @ts-ignore
+global.graphRegistry = global.graphRegistry || new GraphRegistry();
+// @ts-ignore
+export default global.graphRegistry as GraphRegistry;

test/integration/mockingGraphs.test.tsx

@@ -1,8 +1,14 @@
 import React from 'react';
 import { render } from '@testing-library/react';
+import SingletonGraph from '../fixtures/SingletonGraph';
 import MainGraph from '../fixtures/MainGraph';
 import Subgraph from '../fixtures/Subgraph';
-import { Graph, Provides } from '../../src';
+import {
+  Graph,
+  Obsidian,
+  Provides,
+  Singleton,
+} from '../../src';
 import InjectedComponent from '../fixtures/InjectedComponent';
 import { mockGraphs } from '../../testkit';
 
@@ -23,6 +29,32 @@ describe('Test doubles', () => {
     expect(container.textContent).toBe('MockedContent');
   });
 
+  it('Mocks graphs when using Obsidian.obtain', () => {
+    const stringToCompare = Obsidian.obtain(MainGraph).someString();
+    expect(stringToCompare).toBe('Mocked');
+  });
+
+  it('Mocks graphs when using Obsidian.obtain on a Singleton graph'
+  + 'even after the singleton graph was already registered in graph registry', () => {
+    registerSingletonGraphBeforeMocking();
+
+    const stringToCompare = Obsidian.obtain(SingletonGraph).instanceId();
+    expect(stringToCompare).toBe('MockSingleton');
+  });
+
+  function registerSingletonGraphBeforeMocking() {
+    Obsidian.obtain(SingletonGraph);
+    mockGraphs({ SingletonGraph: MockSingletonGraph });
+  }
+
+  @Singleton() @Graph()
+  class MockSingletonGraph extends SingletonGraph {
+    @Provides()
+    override instanceId(): string {
+      return 'MockSingleton';
+    }
+  }
+
   @Graph()
   class MockMainGraph extends MainGraph {
     @Provides()

testkit/mockGraphs.ts

@@ -16,5 +16,15 @@ export function mockGraphs(
       return resolveChain.proceed(Graph, props);
     }
   }();
+
+  clearRegisteredGraphs(graphNameToGraph);
   graphRegistry.addGraphMiddleware(graphMiddleware);
 }
+
+function clearRegisteredGraphs(
+  graphNameToGraph: Record<string, Constructable<ObjectGraph> | ((props: any) => ObjectGraph)>,
+) {
+  for (const graphName of Object.keys(graphNameToGraph)) {
+    graphRegistry.clearGraphAfterItWasMockedInTests(graphName);
+  }
+}