Added assertNoReply to TestFlow/TestAdapter

libraries/botbuilder-core/src/testAdapter.ts

@@ -612,6 +612,40 @@ export class TestFlow {
             this.adapter);
     }
 
+    /**
+     * Generates an assertion that the turn processing logic did not generate a reply from the bot, as expected.
+     * @param description (Optional) Description of the test case. If not provided one will be generated.
+     * @param timeout (Optional) number of milliseconds to wait for a response from bot. Defaults to a value of `3000`.
+     */
+    public assertNoReply(description?: string, timeout?: number): TestFlow {
+        return new TestFlow(
+            this.previous.then(() => {
+                // tslint:disable-next-line:promise-must-complete
+                return new Promise<void>((resolve: any, reject: any): void => {
+                    if (!timeout) { timeout = 3000; }
+                    const start: number = new Date().getTime();
+                    const adapter: TestAdapter = this.adapter;
+
+                    function waitForActivity(): void {
+                        const current: number = new Date().getTime();
+                        if ((current - start) > <number>timeout) {
+                            // Operation timed out and received no reply
+                            resolve();
+                        } else if (adapter.activityBuffer.length > 0) {
+                            // Activity received
+                            const reply: Partial<Activity> = adapter.activityBuffer.shift() as Activity;
+                            assert.strictEqual(reply, undefined, `${ JSON.stringify(reply) } is responded when waiting for no reply: '${ description }'`);
+                            resolve();
+                        } else {
+                            setTimeout(waitForActivity, 5);
+                        }
+                    }
+                    waitForActivity();
+                });
+            }),
+            this.adapter);
+    }
+
     /**
      * Generates an assertion if the bots response is not one of the candidate strings.
      * @param candidates List of candidate responses.

libraries/botbuilder-core/tests/testAdapter.test.js

@@ -214,6 +214,44 @@ describe(`TestAdapter`, function () {
             .catch((err) => done());
     });
 
+    it(`should timeout waiting for assertNoReply() when an Activity is not expected.`, function (done) {
+        const start = new Date().getTime();
+        const adapter = new TestAdapter((context) => {
+            return new Promise((resolve, reject) => {
+                setTimeout(() => resolve(), 600);
+            });
+        });
+        adapter
+            .send('test')
+            .assertNoReply('no message received', 500)
+            .then(() => done());
+    });
+
+    it(`should validate using assertNoReply() that no reply was received, when reply Activity not expected.`, function (done) {
+        const start = new Date().getTime();
+        const adapter = new TestAdapter((context) => {
+            return context.sendActivity(receivedMessage);
+        });
+        adapter
+            .send('test')
+            .assertReply({ text: 'received' })
+            .assertNoReply('should be no additional replies')
+            .then(() => done());
+    });
+
+    it(`should throw an error with assertNoReply() when no reply is expected, but reply Activity was received.`, function (done) {
+        const start = new Date().getTime();
+        const adapter = new TestAdapter((context) => {
+            const activities = [receivedMessage, receivedMessage];
+            context.sendActivity(activities);
+        });
+        adapter
+            .send('test')
+            .assertReply({ text: 'received' })
+            .assertNoReply('should be no additional replies')
+            .catch((err) => done());
+    });
+
     it(`should support calling assertReplyOneOf().`, function (done) {
         const start = new Date().getTime();
         const adapter = new TestAdapter((context) => {