backend-test-utils: automatically determine the plugin ID of tested extension points

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
2023-08-14 12:58:05 +02:00
parent 57a10c6c69
commit 4b0894972f
2 changed files with 180 additions and 14 deletions
@@ -220,4 +220,89 @@ describe('TestBackend', () => {
    expect(res.status).toEqual(200);
    expect(res.body).toEqual({ message: 'pong' });
  });
+
+  it('should provide extension point implementations', async () => {
+    expect.assertions(3);
+
+    const extensionPointA = createExtensionPoint<string>({ id: 'a' });
+    const extensionPointB = createExtensionPoint<string>({ id: 'b' });
+    await expect(
+      startTestBackend({
+        extensionPoints: [
+          [extensionPointA, 'a'],
+          [extensionPointB, 'b'],
+        ],
+        features: [
+          createBackendModule({
+            pluginId: 'testA',
+            moduleId: 'test',
+            register(reg) {
+              reg.registerInit({
+                deps: { ext: extensionPointA },
+                async init({ ext }) {
+                  expect(ext).toBe('a');
+                },
+              });
+            },
+          })(),
+          createBackendModule({
+            pluginId: 'testB',
+            moduleId: 'test',
+            register(reg) {
+              reg.registerInit({
+                deps: { ext: extensionPointB },
+                async init({ ext }) {
+                  expect(ext).toBe('b');
+                },
+              });
+            },
+          })(),
+        ],
+      }),
+    ).resolves.not.toBeUndefined();
+  });
+
+  it('should reject extension point used by multiple plugins', async () => {
+    const extensionPointA = createExtensionPoint<string>({ id: 'a' });
+    await expect(
+      startTestBackend({
+        extensionPoints: [[extensionPointA, 'a']],
+        features: [
+          createBackendModule({
+            pluginId: 'testA',
+            moduleId: 'test',
+            register(reg) {
+              reg.registerInit({
+                deps: { ext: extensionPointA },
+                async init() {},
+              });
+            },
+          })(),
+          createBackendModule({
+            pluginId: 'testB',
+            moduleId: 'test',
+            register(reg) {
+              reg.registerInit({
+                deps: { ext: extensionPointA },
+                async init() {},
+              });
+            },
+          })(),
+        ],
+      }),
+    ).rejects.toThrow(
+      "Extension point registered for plugin 'testA' may not be used by module for plugin 'testB'",
+    );
+  });
+
+  it('should reject extension point not used by any plugin', async () => {
+    const extensionPointA = createExtensionPoint<string>({ id: 'a' });
+    await expect(
+      startTestBackend({
+        extensionPoints: [[extensionPointA, 'a']],
+      }),
+    ).rejects.toThrow(
+      "Unable to determine the plugin ID of extension point(s) 'a'. Tested extension points must be depended on by one or more tested modules.",
+    );
+  });
 });
@@ -30,11 +30,14 @@ import {
  BackendFeature,
  ExtensionPoint,
  coreServices,
-  createBackendPlugin,
+  createBackendModule,
 } from '@backstage/backend-plugin-api';
 import { mockServices } from '../services';
 import { ConfigReader } from '@backstage/config';
 import express from 'express';
+// Direct internal import to avoid duplication
+// eslint-disable-next-line @backstage/no-forbidden-package-imports
+import { InternalBackendFeature } from '@backstage/backend-plugin-api/src/wiring/types';

 /** @public */
 export interface TestBackendOptions<
@@ -87,6 +90,93 @@ const defaultServiceFactories = [
  mockServices.urlReader.factory(),
 ];

+/**
+ * Given a set of extension points and plugins, find
+ * @returns
+ */
+function createExtensionPointTestModules(
+  features: BackendFeature[],
+  extensionPointTuples?: readonly [
+    ref: ExtensionPoint<unknown>,
+    impl: unknown,
+  ][],
+): BackendFeature[] {
+  if (!extensionPointTuples) {
+    return [];
+  }
+
+  const registrations = features.flatMap(feature => {
+    if (feature.$$type !== '@backstage/BackendFeature') {
+      throw new Error(
+        `Failed to add feature, invalid type '${feature.$$type}'`,
+      );
+    }
+    const internalFeature = feature as InternalBackendFeature;
+    if (internalFeature.version !== 'v1') {
+      throw new Error(
+        `Failed to add feature, invalid version '${internalFeature.version}'`,
+      );
+    }
+    return internalFeature.getRegistrations();
+  });
+
+  const extensionPointMap = new Map(
+    extensionPointTuples.map(ep => [ep[0].id, ep]),
+  );
+  const extensionPointsToSort = new Set(extensionPointMap.keys());
+  const extensionPointsByPlugin = new Map<string, string[]>();
+
+  for (const registration of registrations) {
+    if (registration.type === 'module') {
+      const testDep = Object.values(registration.init.deps).filter(dep =>
+        extensionPointsToSort.has(dep.id),
+      );
+      if (testDep.length > 0) {
+        let points = extensionPointsByPlugin.get(registration.pluginId);
+        if (!points) {
+          points = [];
+          extensionPointsByPlugin.set(registration.pluginId, points);
+        }
+        for (const { id } of testDep) {
+          points.push(id);
+          extensionPointsToSort.delete(id);
+        }
+      }
+    }
+  }
+
+  if (extensionPointsToSort.size > 0) {
+    const list = Array.from(extensionPointsToSort)
+      .map(id => `'${id}'`)
+      .join(', ');
+    throw new Error(
+      `Unable to determine the plugin ID of extension point(s) ${list}. ` +
+        'Tested extension points must be depended on by one or more tested modules.',
+    );
+  }
+
+  const modules = [];
+
+  for (const [pluginId, pluginExtensionPointIds] of extensionPointsByPlugin) {
+    modules.push(
+      createBackendModule({
+        pluginId,
+        moduleId: 'testExtensionPointRegistration',
+        register(reg) {
+          for (const id of pluginExtensionPointIds) {
+            const tuple = extensionPointMap.get(id)!;
+            reg.registerExtensionPoint(...tuple);
+          }
+
+          reg.registerInit({ deps: {}, async init() {} });
+        },
+      })(),
+    );
+  }
+
+  return modules;
+}
+
 const backendInstancesToCleanUp = new Array<Backend>();

 /** @public */
@@ -98,7 +188,7 @@ export async function startTestBackend<
 ): Promise<TestBackend> {
  const {
    services = [],
-    extensionPoints = [],
+    extensionPoints,
    features = [],
    ...otherOptions
  } = options;
@@ -194,18 +284,9 @@ export async function startTestBackend<

  backendInstancesToCleanUp.push(backend);

-  backend.add(
-    createBackendPlugin({
-      pluginId: `---test-extension-point-registrar`,
-      register(reg) {
-        for (const [ref, impl] of extensionPoints) {
-          reg.registerExtensionPoint(ref, impl);
-        }
-
-        reg.registerInit({ deps: {}, async init() {} });
-      },
-    })(),
-  );
+  for (const m of createExtensionPointTestModules(features, extensionPoints)) {
+    backend.add(m);
+  }

  for (const feature of features) {
    backend.add(feature);