Fix IModelHost onAfterStartup event and automatic shutdown. (#1043) (#…

…1048)

* Fix IModelHost onAfterStartup event and automatic shutdown.

* Add a comment about use of this in IModelHost.shutdown

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
(cherry picked from commit df26983)

Co-authored-by: Bill Goehrig <33036725+wgoehrig@users.noreply.github.com>

common/changes/@bentley/imodeljs-backend/fix-afterstartup_2021-03-25-17-40.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@bentley/imodeljs-backend",
+      "comment": "",
+      "type": "none"
+    }
+  ],
+  "packageName": "@bentley/imodeljs-backend",
+  "email": "33036725+wgoehrig@users.noreply.github.com"
+}

core/backend/src/IModelHost.ts

@@ -456,6 +456,7 @@ export class IModelHost {
 
     UsageLoggingUtilities.configure({ hostApplicationId: IModelHost.applicationId, hostApplicationVersion: IModelHost.applicationVersion, clientAuthManager: this._clientAuthIntrospectionManager });
     process.once("beforeExit", IModelHost.shutdown);
+    IModelHost.onAfterStartup.raiseEvent();
   }
 
   private static _briefcaseCacheDir: string;
@@ -495,10 +496,11 @@ export class IModelHost {
 
   /** This method must be called when an iModel.js services is shut down. Raises [[onBeforeShutdown]] */
   public static async shutdown(): Promise<void> {
-    if (!this._isValid)
+    // NB: This method is set as a node listener where `this` is unbound
+    if (!IModelHost._isValid)
       return;
 
-    this._isValid = false;
+    IModelHost._isValid = false;
     IModelHost.onBeforeShutdown.raiseEvent();
     IModelHost.platform.shutdown();
     IModelHost.configuration = undefined;

core/backend/src/test/standalone/IModelHost.test.ts

@@ -9,10 +9,12 @@ import { BriefcaseManager } from "../../BriefcaseManager";
 import { RpcRegistry } from "@bentley/imodeljs-common";
 import { IModelTestUtils } from "../IModelTestUtils";
 import { Schemas } from "../../Schema";
+import sinon = require("sinon");
 
 describe("IModelHost", () => {
 
   afterEach(async () => {
+    sinon.restore();
     // Restore the backend to the initial state.
     await IModelTestUtils.shutdownBackend();
     await IModelTestUtils.startBackend();
@@ -37,6 +39,34 @@ describe("IModelHost", () => {
     expect(Schemas.getRegisteredSchema("Functional")).to.exist;
   });
 
+  it("should raise onAfterStartup events", async () => {
+    await IModelTestUtils.shutdownBackend();
+
+    const eventHandler = sinon.spy();
+    IModelHost.onAfterStartup.addOnce(eventHandler);
+    const promise = IModelHost.startup();
+    expect(eventHandler.called).to.be.false;
+    await promise;
+    expect(eventHandler.calledOnce).to.be.true;
+  });
+
+  it("should raise onBeforeShutdown events", async () => {
+    const eventHandler = sinon.spy();
+    IModelHost.onBeforeShutdown.addOnce(eventHandler);
+    await IModelTestUtils.shutdownBackend();
+    expect(eventHandler.calledOnce).to.be.true;
+  });
+
+  it("should auto-shutdown on process beforeExit event", async () => {
+    expect(IModelHost.isValid).to.be.true;
+    const eventHandler = sinon.spy();
+    IModelHost.onBeforeShutdown.addOnce(eventHandler);
+    process.emit("beforeExit", 0);
+    await new Promise((resolve) => setImmediate(resolve));
+    expect(eventHandler.calledOnce).to.be.true;
+    expect(IModelHost.isValid).to.be.false;
+  });
+
   it("should set the briefcase cache directory to expected locations", async () => {
     // Shutdown IModelHost to allow this test to use it.
     await IModelTestUtils.shutdownBackend();