From 98037ca4f4a38ecb7b00cb77e103f95a0ae7e7ff Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Wed, 16 Jun 2021 11:30:10 -0700
Subject: [PATCH 01/13] add support for Teams meeting start/end events

---
 .../botbuilder/src/teamsActivityHandler.ts    |  80 ++++++++++
 .../tests/teamsActivityHandler.test.js        | 143 +++++++++++++++++-
 .../botframework-schema/src/teams/index.ts    |  58 +++++--
 3 files changed, 269 insertions(+), 12 deletions(-)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index 6c50bd1ea0..db9fcde1b3 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -11,8 +11,11 @@ import {
     AdaptiveCardInvokeResponse,
     AppBasedLinkQuery,
     ChannelInfo,
+    Channels,
     FileConsentCardResponse,
     InvokeResponse,
+    MeetingStartEventDetails,
+    MeetingEndEventDetails,
     MessagingExtensionAction,
     MessagingExtensionActionResponse,
     MessagingExtensionQuery,
@@ -924,4 +927,81 @@ export class TeamsActivityHandler extends ActivityHandler {
             await handler(teamsChannelData.team, context, next);
         });
     }
+
+    /**
+     * Runs the _event_ sub-type handlers, as appropriate, and then continues the event emission process.
+     *
+     * @param context The context object for the current turn.
+     * @returns A promise that represents the work queued.
+     *
+     * @remarks
+     * Overwrite this method to support channel-specific behavior across multiple channels or to add
+     * custom event sub-type events.
+     */
+    protected async dispatchEventActivity(context: TurnContext): Promise<void> {
+        await this.handle(context, 'Event', async () => {
+            if (context.activity.channelId == Channels.Msteams) {
+                switch (context.activity.name) {
+                    case 'application/vnd.microsoft.meetingStart':
+                        return this.onTeamsMeetingStart(context);
+                    case 'application/vnd.microsoft.meetingEnd':
+                        return this.onTeamsMeetingEnd(context);
+                }
+            }
+
+            return super.dispatchEventActivity(context);
+        });
+    }
+
+    /**
+     * Invoked when a Meeting Started event activity is received from the connector.
+     * Override this in a derived class to provide logic for when a meeting is started.
+     *
+     * @param context The context for this turn.
+     * @returns A promise that represents the work queued.
+     */
+    protected async onTeamsMeetingStart(context: TurnContext): Promise<void> {
+        await this.handle(context, 'TeamsMeetingStart', this.defaultNextEvent(context));
+    }
+
+    /**
+     * Invoked when a Meeting End event activity is received from the connector.
+     * Override this in a derived class to provide logic for when a meeting is ended.
+     *
+     * @param context The context for this turn.
+     * @returns A promise that represents the work queued.
+     */
+    protected async onTeamsMeetingEnd(context: TurnContext): Promise<void> {
+        await this.handle(context, 'TeamsMeetingEnd', this.defaultNextEvent(context));
+    }
+
+    /**
+     * Registers a handler for when a Teams meeting starts.
+     *
+     * @param handler A callback that handles Meeting Start events.
+     * @returns A promise that represents the work queued.
+     */
+    public onTeamsMeetingStartEvent(
+        handler: (meeting: MeetingStartEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
+    ): this {
+        return this.on('TeamsMeetingStart', async (context, next) => {
+            const meeting = context.activity.value as MeetingStartEventDetails;
+            await handler(meeting, context, next);
+        });
+    }
+
+    /**
+     * Registers a handler for when a Teams meeting ends.
+     *
+     * @param handler A callback that handles Meeting End events.
+     * @returns A promise that represents the work queued.
+     */
+    public onTeamsMeetingEndEvent(
+        handler: (meeting: MeetingEndEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
+    ): this {
+        return this.on('TeamsMeetingEnd', async (context, next) => {
+            const meeting = context.activity.value as MeetingEndEventDetails;
+            await handler(meeting, context, next);
+        });
+    }
 }
diff --git a/libraries/botbuilder/tests/teamsActivityHandler.test.js b/libraries/botbuilder/tests/teamsActivityHandler.test.js
index 4b52a0af17..9433f28aa3 100644
--- a/libraries/botbuilder/tests/teamsActivityHandler.test.js
+++ b/libraries/botbuilder/tests/teamsActivityHandler.test.js
@@ -1,6 +1,6 @@
 const assert = require('assert');
 const { TeamsActivityHandler, TeamsInfo } = require('../');
-const { ActivityTypes, TestAdapter } = require('botbuilder-core');
+const { ActivityTypes, TestAdapter, Channels } = require('botbuilder-core');
 
 function createInvokeActivity(name, value = {}, channelData = {}) {
     const activity = {
@@ -12,7 +12,7 @@ function createInvokeActivity(name, value = {}, channelData = {}) {
     return activity;
 }
 
-describe('TeamsActivityHandler', () => {
+describe('TeamsActivityHandler', function () {
     describe('onTurnActivity()', () => {
         it('should not override the InvokeResponse on the context.turnState if it is set', async function () {
             class InvokeHandler extends TeamsActivityHandler {
@@ -2158,4 +2158,143 @@ describe('TeamsActivityHandler', () => {
                 .startTest();
         });
     });
+
+    describe('onEventActivity()', function () {
+        const expectedMeeting = { id: 'meetingId' };
+
+        function createMeetingEventActivity(start = true) {
+            const activity = {
+                channelId: Channels.Msteams,
+                type: 'event',
+                value: expectedMeeting,
+            };
+
+            if (start) {
+                activity.name = 'application/vnd.microsoft.meetingStart';
+                activity.value.startTime = '2021-06-05T00:01:02.0Z';
+            } else {
+                activity.name = 'application/vnd.microsoft.meetingEnd';
+                activity.value.endTime = '2021-06-05T01:02:03.0Z';
+            }
+
+            return activity;
+        }
+
+        let onEventCalled;
+        let onDialogCalled;
+        this.beforeEach(function () {
+            onEventCalled = false;
+            onDialogCalled = false;
+        });
+
+        it('No MS-Teams routed activity', async function () {
+            const bot = new TeamsActivityHandler();
+
+            const activity = { type: ActivityTypes.Event, channelId: 'no-msteams' };
+
+            const adapter = new TestAdapter(async (context) => {
+                await bot.run(context);
+            });
+
+            bot.onDialog(async (context, next) => {
+                onDialogCalled = true;
+                await next();
+            });
+
+            await adapter
+                .send(activity)
+                .then(() => {
+                    assert(onDialogCalled, 'onDialog handler not called');
+                })
+                .startTest();
+        });
+
+        it('onTeamsMeetingStart routed activity', async function () {
+            const bot = new TeamsActivityHandler();
+
+            let onTeamsMeetingStartCalled = false;
+
+            const activity = createMeetingEventActivity(true);
+
+            bot.onEvent(async (context, next) => {
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                onEventCalled = true;
+                await next();
+            });
+
+            bot.onTeamsMeetingStartEvent(async (meeting, context, next) => {
+                assert(meeting, 'teamsInfo not found');
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                assert.strictEqual(meeting, expectedMeeting);
+                onTeamsMeetingStartCalled = true;
+                await next();
+            });
+
+            bot.onDialog(async (context, next) => {
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                onDialogCalled = true;
+                await next();
+            });
+
+            const adapter = new TestAdapter(async (context) => {
+                await bot.run(context);
+            });
+
+            await adapter
+                .send(activity)
+                .then(() => {
+                    assert(onTeamsMeetingStartCalled);
+                    assert(onEventCalled, 'onConversationUpdate handler not called');
+                    assert(onDialogCalled, 'onDialog handler not called');
+                })
+                .startTest();
+        });
+
+        it('onTeamsMeetingEnd routed activity', async function () {
+            const bot = new TeamsActivityHandler();
+
+            let onTeamsMeetingEndCalled = false;
+
+            const activity = createMeetingEventActivity(false);
+
+            bot.onEvent(async (context, next) => {
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                onEventCalled = true;
+                await next();
+            });
+
+            bot.onTeamsMeetingEndEvent(async (meeting, context, next) => {
+                assert(meeting, 'teamsInfo not found');
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                assert.strictEqual(meeting, expectedMeeting);
+                onTeamsMeetingEndCalled = true;
+                await next();
+            });
+
+            bot.onDialog(async (context, next) => {
+                assert(context, 'context not found');
+                assert(next, 'next not found');
+                onDialogCalled = true;
+                await next();
+            });
+
+            const adapter = new TestAdapter(async (context) => {
+                await bot.run(context);
+            });
+
+            await adapter
+                .send(activity)
+                .then(() => {
+                    assert(onTeamsMeetingEndCalled);
+                    assert(onEventCalled, 'onConversationUpdate handler not called');
+                    assert(onDialogCalled, 'onDialog handler not called');
+                })
+                .startTest();
+        });
+    });
 });
diff --git a/libraries/botframework-schema/src/teams/index.ts b/libraries/botframework-schema/src/teams/index.ts
index f1e9ba7c22..48f428a452 100644
--- a/libraries/botframework-schema/src/teams/index.ts
+++ b/libraries/botframework-schema/src/teams/index.ts
@@ -1690,13 +1690,27 @@ export type Action = 'accept' | 'decline';
 
 /**
  * @interface
- * Specific details of a Teams meeting.
  */
-export interface MeetingDetails {
+interface MeetingDetailsBase {
     /**
      * @member {string} [id] The meeting's Id, encoded as a BASE64 string.
      */
     id: string;
+    /**
+     * @member {string} [joinUrl] The URL used to join the meeting.
+     */
+    joinUrl: string;
+    /**
+     * @member {string} [title] The title of the meeting.
+     */
+    title: string;
+}
+
+/**
+ * @interface
+ * Specific details of a Teams meeting.
+ */
+export interface MeetingDetails extends MeetingDetailsBase {
     /**
      * @member {string} [msGraphResourceId] The MsGraphResourceId, used specifically for MS Graph API calls.
      */
@@ -1709,14 +1723,6 @@ export interface MeetingDetails {
      * @member {Date} [scheduledEndTime] The meeting's scheduled end time, in UTC.
      */
     scheduledEndTime: Date;
-    /**
-     * @member {string} [joinUrl] The URL used to join the meeting.
-     */
-    joinUrl: string;
-    /**
-     * @member {string} [title] The title of the meeting.
-     */
-    title: string;
     /**
      * @member {string} [type] The meeting's type.
      */
@@ -1741,3 +1747,35 @@ export interface MeetingInfo {
      */
     organizer: TeamsChannelAccount;
 }
+
+/**
+ * @interface
+ */
+interface MeetingEventDetails extends MeetingDetailsBase {
+    /**
+     * @member {string} [type] The meeting's type.
+     */
+    meetingType: string;
+}
+
+/**
+ * @interface
+ * Specific details of a Teams meeting start event.
+ */
+export interface MeetingStartEventDetails extends MeetingEventDetails {
+    /**
+     * @member {Date} [startTime] Timestamp for meeting start, in UTC.
+     */
+    startTime: Date;
+}
+
+/**
+ * @interface
+ * Specific details of a Teams meeting end event.
+ */
+export interface MeetingEndEventDetails extends MeetingEventDetails {
+    /**
+     * @member {Date} [endTime] Timestamp for meeting end, in UTC.
+     */
+    endTime: Date;
+}

From ab072fe00874376f3a46217f22596312913ea2de Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Wed, 16 Jun 2021 14:46:19 -0700
Subject: [PATCH 02/13] api-extractor fix

---
 libraries/botbuilder/etc/botbuilder.api.md    |  7 +++++++
 .../etc/botframework-schema.api.md            | 19 +++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/libraries/botbuilder/etc/botbuilder.api.md b/libraries/botbuilder/etc/botbuilder.api.md
index 3e47aa5420..7ddca2306d 100644
--- a/libraries/botbuilder/etc/botbuilder.api.md
+++ b/libraries/botbuilder/etc/botbuilder.api.md
@@ -38,6 +38,8 @@ import { INodeSocket } from 'botframework-streaming';
 import { InvokeResponse } from 'botbuilder-core';
 import { IReceiveRequest } from 'botframework-streaming';
 import { IStreamingTransportServer } from 'botframework-streaming';
+import { MeetingEndEventDetails } from 'botbuilder-core';
+import { MeetingStartEventDetails } from 'botbuilder-core';
 import { MessagingExtensionAction } from 'botbuilder-core';
 import { MessagingExtensionActionResponse } from 'botbuilder-core';
 import { MessagingExtensionQuery } from 'botbuilder-core';
@@ -299,6 +301,7 @@ export class StreamingHttpClient implements HttpClient {
 // @public
 export class TeamsActivityHandler extends ActivityHandler {
     protected dispatchConversationUpdateActivity(context: TurnContext): Promise<void>;
+    protected dispatchEventActivity(context: TurnContext): Promise<void>;
     protected handleAdaptiveCardAction(context: TurnContext): Promise<AdaptiveCardInvokeResponse>;
     protected handleTeamsAppBasedLinkQuery(context: TurnContext, query: AppBasedLinkQuery): Promise<MessagingExtensionResponse>;
     protected handleTeamsCardActionInvoke(context: TurnContext): Promise<InvokeResponse>;
@@ -333,6 +336,10 @@ export class TeamsActivityHandler extends ActivityHandler {
     // (undocumented)
     protected onTeamsChannelRestored(context: any): Promise<void>;
     onTeamsChannelRestoredEvent(handler: (channelInfo: ChannelInfo, teamInfo: TeamInfo, context: TurnContext, next: () => Promise<void>) => Promise<void>): this;
+    protected onTeamsMeetingEnd(context: TurnContext): Promise<void>;
+    onTeamsMeetingEndEvent(handler: (meeting: MeetingEndEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>): this;
+    protected onTeamsMeetingStart(context: TurnContext): Promise<void>;
+    onTeamsMeetingStartEvent(handler: (meeting: MeetingStartEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>): this;
     protected onTeamsMembersAdded(context: TurnContext): Promise<void>;
     onTeamsMembersAddedEvent(handler: (membersAdded: TeamsChannelAccount[], teamInfo: TeamInfo, context: TurnContext, next: () => Promise<void>) => Promise<void>): this;
     protected onTeamsMembersRemoved(context: TurnContext): Promise<void>;
diff --git a/libraries/botframework-schema/etc/botframework-schema.api.md b/libraries/botframework-schema/etc/botframework-schema.api.md
index 97a8704d53..c1dd4162f9 100644
--- a/libraries/botframework-schema/etc/botframework-schema.api.md
+++ b/libraries/botframework-schema/etc/botframework-schema.api.md
@@ -875,17 +875,23 @@ export interface Meeting {
     role?: string;
 }
 
+// Warning: (ae-forgotten-export) The symbol "MeetingDetailsBase" needs to be exported by the entry point index.d.ts
+//
 // @public
-export interface MeetingDetails {
-    id: string;
-    joinUrl: string;
+export interface MeetingDetails extends MeetingDetailsBase {
     msGraphResourceId: string;
     scheduledEndTime: Date;
     scheduledStartTime: Date;
-    title: string;
     type: string;
 }
 
+// Warning: (ae-forgotten-export) The symbol "MeetingEventDetails" needs to be exported by the entry point index.d.ts
+//
+// @public
+export interface MeetingEndEventDetails extends MeetingEventDetails {
+    endTime: Date;
+}
+
 // @public
 export interface MeetingInfo {
     conversation: ConversationAccount;
@@ -893,6 +899,11 @@ export interface MeetingInfo {
     organizer: TeamsChannelAccount;
 }
 
+// @public
+export interface MeetingStartEventDetails extends MeetingEventDetails {
+    startTime: Date;
+}
+
 // @public
 export interface Mention {
     mentioned: ChannelAccount;

From 769eb2134822783104cf5345f55613bdb46d97c6 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Wed, 16 Jun 2021 16:48:16 -0700
Subject: [PATCH 03/13] camelCase event payloads

---
 .../botbuilder/src/teamsActivityHandler.ts    | 26 +++++++++++++++++--
 .../etc/botframework-schema.api.md            |  7 +++--
 .../botframework-schema/src/teams/index.ts    |  2 +-
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index db9fcde1b3..3403e827e9 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -14,6 +14,7 @@ import {
     Channels,
     FileConsentCardResponse,
     InvokeResponse,
+    MeetingEventDetails,
     MeetingStartEventDetails,
     MeetingEndEventDetails,
     MessagingExtensionAction,
@@ -985,7 +986,9 @@ export class TeamsActivityHandler extends ActivityHandler {
         handler: (meeting: MeetingStartEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
     ): this {
         return this.on('TeamsMeetingStart', async (context, next) => {
-            const meeting = context.activity.value as MeetingStartEventDetails;
+            const meeting = this.convertMeetingEventDetailsToCamelCase<MeetingStartEventDetails>(
+                context.activity.value
+            );
             await handler(meeting, context, next);
         });
     }
@@ -1000,8 +1003,27 @@ export class TeamsActivityHandler extends ActivityHandler {
         handler: (meeting: MeetingEndEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
     ): this {
         return this.on('TeamsMeetingEnd', async (context, next) => {
-            const meeting = context.activity.value as MeetingEndEventDetails;
+            const meeting = this.convertMeetingEventDetailsToCamelCase<MeetingEndEventDetails>(context.activity.value);
             await handler(meeting, context, next);
         });
     }
+
+    private convertMeetingEventDetailsToCamelCase<T extends MeetingStartEventDetails | MeetingEndEventDetails>(
+        meeting: Record<string, string>
+    ): T {
+        const convertedMeeting: MeetingEventDetails = {
+            id: meeting.Id,
+            joinUrl: meeting.JoinUrl,
+            meetingType: meeting.MeetingType,
+            title: meeting.Title,
+        };
+
+        if (meeting.StartTime) {
+            (convertedMeeting as MeetingStartEventDetails).startTime = new Date(meeting.StartTime);
+        } else {
+            (convertedMeeting as MeetingEndEventDetails).endTime = new Date(meeting.EndTime);
+        }
+
+        return convertedMeeting as T;
+    }
 }
diff --git a/libraries/botframework-schema/etc/botframework-schema.api.md b/libraries/botframework-schema/etc/botframework-schema.api.md
index c1dd4162f9..df08091616 100644
--- a/libraries/botframework-schema/etc/botframework-schema.api.md
+++ b/libraries/botframework-schema/etc/botframework-schema.api.md
@@ -885,13 +885,16 @@ export interface MeetingDetails extends MeetingDetailsBase {
     type: string;
 }
 
-// Warning: (ae-forgotten-export) The symbol "MeetingEventDetails" needs to be exported by the entry point index.d.ts
-//
 // @public
 export interface MeetingEndEventDetails extends MeetingEventDetails {
     endTime: Date;
 }
 
+// @public (undocumented)
+export interface MeetingEventDetails extends MeetingDetailsBase {
+    meetingType: string;
+}
+
 // @public
 export interface MeetingInfo {
     conversation: ConversationAccount;
diff --git a/libraries/botframework-schema/src/teams/index.ts b/libraries/botframework-schema/src/teams/index.ts
index 48f428a452..e17367a084 100644
--- a/libraries/botframework-schema/src/teams/index.ts
+++ b/libraries/botframework-schema/src/teams/index.ts
@@ -1751,7 +1751,7 @@ export interface MeetingInfo {
 /**
  * @interface
  */
-interface MeetingEventDetails extends MeetingDetailsBase {
+export interface MeetingEventDetails extends MeetingDetailsBase {
     /**
      * @member {string} [type] The meeting's type.
      */

From cbc67ac578c964fbc5df4e61e4b73b2362a35218 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Wed, 16 Jun 2021 16:49:15 -0700
Subject: [PATCH 04/13] add method comment for casing

---
 libraries/botbuilder/src/teamsActivityHandler.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index 3403e827e9..c17f980cd0 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -1008,6 +1008,8 @@ export class TeamsActivityHandler extends ActivityHandler {
         });
     }
 
+    // The payload from Teams comes in with TitleCase keys, so we'll convert them to camelCase
+    // to maintain JSON and JS standard practices.
     private convertMeetingEventDetailsToCamelCase<T extends MeetingStartEventDetails | MeetingEndEventDetails>(
         meeting: Record<string, string>
     ): T {

From adef19ad825182ee75b2951b669be95ea715257d Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Wed, 16 Jun 2021 17:10:24 -0700
Subject: [PATCH 05/13] adjust tests for casing changes

---
 .../tests/teamsActivityHandler.test.js           | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/libraries/botbuilder/tests/teamsActivityHandler.test.js b/libraries/botbuilder/tests/teamsActivityHandler.test.js
index 9433f28aa3..d42cdad4f6 100644
--- a/libraries/botbuilder/tests/teamsActivityHandler.test.js
+++ b/libraries/botbuilder/tests/teamsActivityHandler.test.js
@@ -2160,21 +2160,22 @@ describe('TeamsActivityHandler', function () {
     });
 
     describe('onEventActivity()', function () {
-        const expectedMeeting = { id: 'meetingId' };
+        let meetingPayload = { id: 'meetingId' };
 
+        // Note: Teams payload is TitleCase.
         function createMeetingEventActivity(start = true) {
             const activity = {
                 channelId: Channels.Msteams,
                 type: 'event',
-                value: expectedMeeting,
+                value: meetingPayload,
             };
 
             if (start) {
                 activity.name = 'application/vnd.microsoft.meetingStart';
-                activity.value.startTime = '2021-06-05T00:01:02.0Z';
+                activity.value.StartTime = '2021-06-05T00:01:02.0Z';
             } else {
                 activity.name = 'application/vnd.microsoft.meetingEnd';
-                activity.value.endTime = '2021-06-05T01:02:03.0Z';
+                activity.value.EndTime = '2021-06-05T01:02:03.0Z';
             }
 
             return activity;
@@ -2183,6 +2184,7 @@ describe('TeamsActivityHandler', function () {
         let onEventCalled;
         let onDialogCalled;
         this.beforeEach(function () {
+            meetingPayload = { id: 'meetingId' };
             onEventCalled = false;
             onDialogCalled = false;
         });
@@ -2227,7 +2229,8 @@ describe('TeamsActivityHandler', function () {
                 assert(meeting, 'teamsInfo not found');
                 assert(context, 'context not found');
                 assert(next, 'next not found');
-                assert.strictEqual(meeting, expectedMeeting);
+                assert.strictEqual(meeting.id, meetingPayload.Id);
+                assert.strictEqual(meeting.startTime.toString(), new Date(meetingPayload.StartTime).toString());
                 onTeamsMeetingStartCalled = true;
                 await next();
             });
@@ -2271,7 +2274,8 @@ describe('TeamsActivityHandler', function () {
                 assert(meeting, 'teamsInfo not found');
                 assert(context, 'context not found');
                 assert(next, 'next not found');
-                assert.strictEqual(meeting, expectedMeeting);
+                assert.strictEqual(meeting.id, meetingPayload.Id);
+                assert.strictEqual(meeting.endTime.toString(), new Date(meetingPayload.EndTime).toString());
                 onTeamsMeetingEndCalled = true;
                 await next();
             });

From 4c550532b4354018f6dec0d927961ac790b7ee00 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Thu, 17 Jun 2021 11:45:39 -0700
Subject: [PATCH 06/13] minor doc adjustment

---
 libraries/botframework-schema/src/teams/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/botframework-schema/src/teams/index.ts b/libraries/botframework-schema/src/teams/index.ts
index e17367a084..41c1a7d282 100644
--- a/libraries/botframework-schema/src/teams/index.ts
+++ b/libraries/botframework-schema/src/teams/index.ts
@@ -1753,7 +1753,7 @@ export interface MeetingInfo {
  */
 export interface MeetingEventDetails extends MeetingDetailsBase {
     /**
-     * @member {string} [type] The meeting's type.
+     * @member {string} [meetingType] The meeting's type.
      */
     meetingType: string;
 }

From 8b39ff83130224fc4430723c73ac149b7afe17c8 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Thu, 17 Jun 2021 11:52:15 -0700
Subject: [PATCH 07/13] don't shortcut parent dispatchEventActivity()

---
 libraries/botbuilder/src/teamsActivityHandler.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index c17f980cd0..fed1a006f0 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -944,9 +944,11 @@ export class TeamsActivityHandler extends ActivityHandler {
             if (context.activity.channelId == Channels.Msteams) {
                 switch (context.activity.name) {
                     case 'application/vnd.microsoft.meetingStart':
-                        return this.onTeamsMeetingStart(context);
+                        await this.onTeamsMeetingStart(context);
+                        break;
                     case 'application/vnd.microsoft.meetingEnd':
-                        return this.onTeamsMeetingEnd(context);
+                        await this.onTeamsMeetingEnd(context);
+                        break;
                 }
             }
 

From f2645e603ed14b9d5be1a0b626410b56aee53b45 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Thu, 17 Jun 2021 16:17:05 -0700
Subject: [PATCH 08/13] add err

---
 libraries/botbuilder/src/teamsActivityHandler.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index fed1a006f0..3d62144a38 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -1024,8 +1024,12 @@ export class TeamsActivityHandler extends ActivityHandler {
 
         if (meeting.StartTime) {
             (convertedMeeting as MeetingStartEventDetails).startTime = new Date(meeting.StartTime);
-        } else {
+        } else if (meeting.EndTime) {
             (convertedMeeting as MeetingEndEventDetails).endTime = new Date(meeting.EndTime);
+        } else {
+            throw new Error(
+                `Invalid meeting. It does not include StartTime or EndTime: ${JSON.stringify(meeting, null, 2)}`
+            );
         }
 
         return convertedMeeting as T;

From 8eda7e64da193d1674f9e4c69a4120318934e717 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Fri, 18 Jun 2021 09:38:49 -0700
Subject: [PATCH 09/13] Revert "don't shortcut parent dispatchEventActivity()"

This reverts commit 8b39ff83130224fc4430723c73ac149b7afe17c8.
---
 libraries/botbuilder/src/teamsActivityHandler.ts | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index 3d62144a38..a63c0e4b0b 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -944,11 +944,9 @@ export class TeamsActivityHandler extends ActivityHandler {
             if (context.activity.channelId == Channels.Msteams) {
                 switch (context.activity.name) {
                     case 'application/vnd.microsoft.meetingStart':
-                        await this.onTeamsMeetingStart(context);
-                        break;
+                        return this.onTeamsMeetingStart(context);
                     case 'application/vnd.microsoft.meetingEnd':
-                        await this.onTeamsMeetingEnd(context);
-                        break;
+                        return this.onTeamsMeetingEnd(context);
                 }
             }
 

From 52a30baa151efb8c4fda872012c935612c9cfabd Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Fri, 18 Jun 2021 12:04:38 -0700
Subject: [PATCH 10/13] PR review adjustments

---
 .../botbuilder-core/src/activityHandler.ts    | 40 +++++-----
 .../src/activityHandlerBase.ts                | 34 ++++-----
 libraries/botbuilder/package.json             |  1 +
 .../botbuilder/src/teamsActivityHandler.ts    | 74 +++++++++++--------
 .../tests/teamsActivityHandler.test.js        |  4 +-
 yarn.lock                                     |  2 +-
 6 files changed, 83 insertions(+), 72 deletions(-)

diff --git a/libraries/botbuilder-core/src/activityHandler.ts b/libraries/botbuilder-core/src/activityHandler.ts
index 7bc26de394..8f97594581 100644
--- a/libraries/botbuilder-core/src/activityHandler.ts
+++ b/libraries/botbuilder-core/src/activityHandler.ts
@@ -457,7 +457,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to use custom logic for emitting events.
+     * Override this method to use custom logic for emitting events.
      *
      * The default logic is to call any handlers registered via [onTurn](xref:botbuilder-core.ActivityHandler.onTurn),
      * and then continue by calling [ActivityHandlerBase.onTurnActivity](xref:botbuilder-core.ActivityHandlerBase.onTurnActivity).
@@ -474,7 +474,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onMessage](xref:botbuilder-core.ActivityHandler.onMessage),
@@ -489,7 +489,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      * The default logic is to check for a signIn invoke and handle that
      * and then continue by calling [defaultNextEvent](xref:botbuilder-core.ActivityHandler.defaultNextEvent).
      */
@@ -531,7 +531,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      */
     protected async onSignInInvoke(context: TurnContext): Promise<void> {
         throw new InvokeException(StatusCodes.NOT_IMPLEMENTED);
@@ -556,7 +556,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onEndOfConversationActivity](xref:botbuilder-core.ActivityHandler.onMessage),
@@ -572,7 +572,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onTypingActivity](xref:botbuilder-core.ActivityHandler.onTypingActivity),
@@ -588,7 +588,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onInstallationUpdateActivity](xref:botbuilder-core.ActivityHandler.onInstallationUpdateActivity),
@@ -624,7 +624,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels or to add
+     * Override this method to support channel-specific behavior across multiple channels or to add
      * custom conversation update sub-type events.
      *
      * The default logic is:
@@ -651,7 +651,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onInstallationUpdateAdd](xref:botbuilder-core.ActivityHandler.onInstallationUpdateAdd),
@@ -667,7 +667,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onInstallationUpdateRemove](xref:botbuilder-core.ActivityHandler.onInstallationUpdateRemove),
@@ -683,7 +683,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onUnrecognizedActivityType](xref:botbuilder-core.ActivityHandler.onUnrecognizedActivityType),
@@ -743,7 +743,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onConversationUpdate](xref:botbuilder-core.ActivityHandler.onConversationUpdate),
@@ -762,7 +762,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels or to add
+     * Override this method to support channel-specific behavior across multiple channels or to add
      * custom conversation update sub-type events.
      *
      * The default logic is:
@@ -786,7 +786,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onMessageReaction](xref:botbuilder-core.ActivityHandler.onMessageReaction),
@@ -806,7 +806,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onReactionsAdded](xref:botbuilder-core.ActivityHandler.onReactionsAdded),
@@ -823,7 +823,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onReactionsRemoved](xref:botbuilder-core.ActivityHandler.onReactionsRemoved),
@@ -842,7 +842,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels or to add
+     * Override this method to support channel-specific behavior across multiple channels or to add
      * custom message reaction sub-type events.
      *
      * The default logic is:
@@ -864,7 +864,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels.
+     * Override this method to support channel-specific behavior across multiple channels.
      *
      * The default logic is to call any handlers registered via
      * [onEvent](xref:botbuilder-core.ActivityHandler.onEvent),
@@ -883,7 +883,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels or to add custom event sub-type events.
+     * Override this method to support channel-specific behavior across multiple channels or to add custom event sub-type events.
      * For certain channels, such as  Web Chat and custom Direct Line clients, developers can emit custom event activities from the client.
      *
      * The default logic is:
@@ -905,7 +905,7 @@ export class ActivityHandler extends ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to use custom logic for emitting events.
+     * Override this method to use custom logic for emitting events.
      *
      * The default logic is to call any handlers registered via [onDialog](xref:botbuilder-core.ActivityHandler.onDialog),
      * and then complete the event emission process.
diff --git a/libraries/botbuilder-core/src/activityHandlerBase.ts b/libraries/botbuilder-core/src/activityHandlerBase.ts
index 40815037de..b86bb9f13e 100644
--- a/libraries/botbuilder-core/src/activityHandlerBase.ts
+++ b/libraries/botbuilder-core/src/activityHandlerBase.ts
@@ -6,7 +6,7 @@ import { ActivityTypes, ChannelAccount, MessageReaction, TurnContext } from '.';
 import { InvokeResponse } from './invokeResponse';
 import { StatusCodes } from './statusCodes';
 
-// This key is exported internally so that subclassed ActivityHandlers and BotAdapters will not overwrite any already set InvokeResponses.
+// This key is exported internally so that subclassed ActivityHandlers and BotAdapters will not override any already set InvokeResponses.
 export const INVOKE_RESPONSE_KEY = Symbol('invokeResponse');
 
 /**
@@ -37,7 +37,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to use custom logic for emitting events.
+     * Override this method to use custom logic for emitting events.
      *
      * The default logic is to call any type-specific and sub-type handlers registered via
      * the various _on event_ methods. Type-specific events are defined for:
@@ -97,7 +97,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _message_ handlers and then continue the event
+     * Override this method to run registered _message_ handlers and then continue the event
      * emission process.
      */
     protected async onMessageActivity(context: TurnContext): Promise<void> {
@@ -110,7 +110,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _conversation update_ handlers and then continue the event
+     * Override this method to run registered _conversation update_ handlers and then continue the event
      * emission process.
      *
      * The default logic is:
@@ -145,7 +145,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _message reaction_ handlers and then continue the event
+     * Override this method to run registered _message reaction_ handlers and then continue the event
      * emission process.
      *
      * The default logic is:
@@ -168,7 +168,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _event_ handlers and then continue the event
+     * Override this method to run registered _event_ handlers and then continue the event
      * emission process.
      */
     protected async onEventActivity(context: TurnContext): Promise<void> {
@@ -181,7 +181,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to handle particular invoke calls.
+     * Override this method to handle particular invoke calls.
      */
     protected async onInvokeActivity(context: TurnContext): Promise<InvokeResponse> {
         return { status: StatusCodes.NOT_IMPLEMENTED };
@@ -193,7 +193,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _end of conversation_ handlers and then continue the event
+     * Override this method to run registered _end of conversation_ handlers and then continue the event
      * emission process.
      */
     protected async onEndOfConversationActivity(context: TurnContext): Promise<void> {
@@ -206,7 +206,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _typing_ handlers and then continue the event
+     * Override this method to run registered _typing_ handlers and then continue the event
      * emission process.
      */
     protected async onTypingActivity(context: TurnContext): Promise<void> {
@@ -219,7 +219,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _installationupdate_ handlers and then continue the event
+     * Override this method to run registered _installationupdate_ handlers and then continue the event
      * emission process.
      */
     protected async onInstallationUpdateActivity(context: TurnContext): Promise<void> {
@@ -241,7 +241,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _installationupdateadd_ handlers and then continue the event
+     * Override this method to run registered _installationupdateadd_ handlers and then continue the event
      * emission process.
      */
     protected async onInstallationUpdateAddActivity(context: TurnContext): Promise<void> {
@@ -254,7 +254,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _installationupdateremove_ handlers and then continue the event
+     * Override this method to run registered _installationupdateremove_ handlers and then continue the event
      * emission process.
      */
     protected async onInstallationUpdateRemoveActivity(context: TurnContext): Promise<void> {
@@ -267,7 +267,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _unrecognized_ handlers and then continue the event
+     * Override this method to run registered _unrecognized_ handlers and then continue the event
      * emission process.
      */
     protected async onUnrecognizedActivity(context: TurnContext): Promise<void> {
@@ -282,7 +282,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _members added_ handlers and then continue the event
+     * Override this method to run registered _members added_ handlers and then continue the event
      * emission process.
      */
     protected async onMembersAddedActivity(membersAdded: ChannelAccount[], context: TurnContext): Promise<void> {
@@ -297,7 +297,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _members removed_ handlers and then continue the event
+     * Override this method to run registered _members removed_ handlers and then continue the event
      * emission process.
      */
     protected async onMembersRemovedActivity(membersRemoved: ChannelAccount[], context: TurnContext): Promise<void> {
@@ -312,7 +312,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _reactions added_ handlers and then continue the event
+     * Override this method to run registered _reactions added_ handlers and then continue the event
      * emission process.
      */
     protected async onReactionsAddedActivity(reactionsAdded: MessageReaction[], context: TurnContext): Promise<void> {
@@ -327,7 +327,7 @@ export class ActivityHandlerBase {
      * @param context The context object for the current turn.
      *
      * @remarks
-     * Overwrite this method to run registered _reactions removed_ handlers and then continue the event
+     * Override this method to run registered _reactions removed_ handlers and then continue the event
      * emission process.
      */
     protected async onReactionsRemovedActivity(
diff --git a/libraries/botbuilder/package.json b/libraries/botbuilder/package.json
index 68a8cc6fc8..2ce69ceb57 100644
--- a/libraries/botbuilder/package.json
+++ b/libraries/botbuilder/package.json
@@ -38,6 +38,7 @@
     "filenamify": "^4.1.0",
     "fs-extra": "^7.0.1",
     "htmlparser2": "^6.0.1",
+    "runtypes": "6.3.0",
     "uuid": "^8.3.2"
   },
   "devDependencies": {
diff --git a/libraries/botbuilder/src/teamsActivityHandler.ts b/libraries/botbuilder/src/teamsActivityHandler.ts
index a63c0e4b0b..ac511ddd5f 100644
--- a/libraries/botbuilder/src/teamsActivityHandler.ts
+++ b/libraries/botbuilder/src/teamsActivityHandler.ts
@@ -36,6 +36,23 @@ import {
     verifyStateOperationName,
 } from 'botbuilder-core';
 import { TeamsInfo } from './teamsInfo';
+import * as t from 'runtypes';
+
+const TeamsMeetingStartT = t.Record({
+    Id: t.String,
+    JoinUrl: t.String,
+    MeetingType: t.String,
+    Title: t.String,
+    StartTime: t.String,
+});
+
+const TeamsMeetingEndT = t.Record({
+    Id: t.String,
+    JoinUrl: t.String,
+    MeetingType: t.String,
+    Title: t.String,
+    EndTime: t.String,
+});
 
 /**
  * Adds support for Microsoft Teams specific events and interactions.
@@ -936,12 +953,12 @@ export class TeamsActivityHandler extends ActivityHandler {
      * @returns A promise that represents the work queued.
      *
      * @remarks
-     * Overwrite this method to support channel-specific behavior across multiple channels or to add
+     * Override this method to support channel-specific behavior across multiple channels or to add
      * custom event sub-type events.
      */
     protected async dispatchEventActivity(context: TurnContext): Promise<void> {
         await this.handle(context, 'Event', async () => {
-            if (context.activity.channelId == Channels.Msteams) {
+            if (context.activity.channelId === Channels.Msteams) {
                 switch (context.activity.name) {
                     case 'application/vnd.microsoft.meetingStart':
                         return this.onTeamsMeetingStart(context);
@@ -986,10 +1003,18 @@ export class TeamsActivityHandler extends ActivityHandler {
         handler: (meeting: MeetingStartEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
     ): this {
         return this.on('TeamsMeetingStart', async (context, next) => {
-            const meeting = this.convertMeetingEventDetailsToCamelCase<MeetingStartEventDetails>(
-                context.activity.value
+            const meeting = TeamsMeetingStartT.check(context.activity.value);
+            await handler(
+                {
+                    id: meeting.Id,
+                    joinUrl: meeting.JoinUrl,
+                    meetingType: meeting.MeetingType,
+                    startTime: new Date(meeting.StartTime),
+                    title: meeting.Title,
+                },
+                context,
+                next
             );
-            await handler(meeting, context, next);
         });
     }
 
@@ -1003,33 +1028,18 @@ export class TeamsActivityHandler extends ActivityHandler {
         handler: (meeting: MeetingEndEventDetails, context: TurnContext, next: () => Promise<void>) => Promise<void>
     ): this {
         return this.on('TeamsMeetingEnd', async (context, next) => {
-            const meeting = this.convertMeetingEventDetailsToCamelCase<MeetingEndEventDetails>(context.activity.value);
-            await handler(meeting, context, next);
-        });
-    }
-
-    // The payload from Teams comes in with TitleCase keys, so we'll convert them to camelCase
-    // to maintain JSON and JS standard practices.
-    private convertMeetingEventDetailsToCamelCase<T extends MeetingStartEventDetails | MeetingEndEventDetails>(
-        meeting: Record<string, string>
-    ): T {
-        const convertedMeeting: MeetingEventDetails = {
-            id: meeting.Id,
-            joinUrl: meeting.JoinUrl,
-            meetingType: meeting.MeetingType,
-            title: meeting.Title,
-        };
-
-        if (meeting.StartTime) {
-            (convertedMeeting as MeetingStartEventDetails).startTime = new Date(meeting.StartTime);
-        } else if (meeting.EndTime) {
-            (convertedMeeting as MeetingEndEventDetails).endTime = new Date(meeting.EndTime);
-        } else {
-            throw new Error(
-                `Invalid meeting. It does not include StartTime or EndTime: ${JSON.stringify(meeting, null, 2)}`
+            const meeting = TeamsMeetingEndT.check(context.activity.value);
+            await handler(
+                {
+                    id: meeting.Id,
+                    joinUrl: meeting.JoinUrl,
+                    meetingType: meeting.MeetingType,
+                    endTime: new Date(meeting.EndTime),
+                    title: meeting.Title,
+                },
+                context,
+                next
             );
-        }
-
-        return convertedMeeting as T;
+        });
     }
 }
diff --git a/libraries/botbuilder/tests/teamsActivityHandler.test.js b/libraries/botbuilder/tests/teamsActivityHandler.test.js
index d42cdad4f6..e5718b32f3 100644
--- a/libraries/botbuilder/tests/teamsActivityHandler.test.js
+++ b/libraries/botbuilder/tests/teamsActivityHandler.test.js
@@ -2160,7 +2160,7 @@ describe('TeamsActivityHandler', function () {
     });
 
     describe('onEventActivity()', function () {
-        let meetingPayload = { id: 'meetingId' };
+        let meetingPayload;
 
         // Note: Teams payload is TitleCase.
         function createMeetingEventActivity(start = true) {
@@ -2184,7 +2184,7 @@ describe('TeamsActivityHandler', function () {
         let onEventCalled;
         let onDialogCalled;
         this.beforeEach(function () {
-            meetingPayload = { id: 'meetingId' };
+            meetingPayload = { Id: 'meetingId' };
             onEventCalled = false;
             onDialogCalled = false;
         });
diff --git a/yarn.lock b/yarn.lock
index 4ff58e5e9d..a9a92f2a85 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10876,7 +10876,7 @@ run-queue@^1.0.0, run-queue@^1.0.3:
   dependencies:
     aproba "^1.1.1"
 
-runtypes@~6.3.0:
+runtypes@6.3.0, runtypes@~6.3.0:
   version "6.3.0"
   resolved "https://registry.yarnpkg.com/runtypes/-/runtypes-6.3.0.tgz#bd88392c21f471bd45591d5eabaa4644ca7cdf3c"
   integrity sha512-FTNUs13CIrCTjReBOaeY/8EY1LYIQVkkwyE9z5MCjZe9uew9/8TRbWF1PcTczgTFfGBjkjUKeedFWU2O3ExjPg==

From c56cc8d32887ffb3122e8d27d0ffba1986300020 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Fri, 18 Jun 2021 12:11:47 -0700
Subject: [PATCH 11/13] tilde

---
 libraries/botbuilder/package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/botbuilder/package.json b/libraries/botbuilder/package.json
index 2ce69ceb57..eff20ba31d 100644
--- a/libraries/botbuilder/package.json
+++ b/libraries/botbuilder/package.json
@@ -38,7 +38,7 @@
     "filenamify": "^4.1.0",
     "fs-extra": "^7.0.1",
     "htmlparser2": "^6.0.1",
-    "runtypes": "6.3.0",
+    "runtypes": "~6.3.0",
     "uuid": "^8.3.2"
   },
   "devDependencies": {

From 0d464d56bca98e2102dbbfe787b292759679b753 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Fri, 18 Jun 2021 12:50:14 -0700
Subject: [PATCH 12/13] make tests work w/ runtypes

---
 libraries/botbuilder/tests/teamsActivityHandler.test.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libraries/botbuilder/tests/teamsActivityHandler.test.js b/libraries/botbuilder/tests/teamsActivityHandler.test.js
index e5718b32f3..86c6f33ea3 100644
--- a/libraries/botbuilder/tests/teamsActivityHandler.test.js
+++ b/libraries/botbuilder/tests/teamsActivityHandler.test.js
@@ -2184,7 +2184,12 @@ describe('TeamsActivityHandler', function () {
         let onEventCalled;
         let onDialogCalled;
         this.beforeEach(function () {
-            meetingPayload = { Id: 'meetingId' };
+            meetingPayload = {
+                Id: 'meetingId',
+                JoinUrl: 'https://joinUrl',
+                MeetingType: 'Scheduled',
+                title: 'someTitle'
+            };
             onEventCalled = false;
             onDialogCalled = false;
         });

From 00c66d68297c055cca6481cf07dce13fce63aac4 Mon Sep 17 00:00:00 2001
From: Michael Richardson <mrichardson@microsoft.com>
Date: Fri, 18 Jun 2021 13:15:51 -0700
Subject: [PATCH 13/13] cap fix

---
 libraries/botbuilder/tests/teamsActivityHandler.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/botbuilder/tests/teamsActivityHandler.test.js b/libraries/botbuilder/tests/teamsActivityHandler.test.js
index 86c6f33ea3..caa68c708d 100644
--- a/libraries/botbuilder/tests/teamsActivityHandler.test.js
+++ b/libraries/botbuilder/tests/teamsActivityHandler.test.js
@@ -2188,7 +2188,7 @@ describe('TeamsActivityHandler', function () {
                 Id: 'meetingId',
                 JoinUrl: 'https://joinUrl',
                 MeetingType: 'Scheduled',
-                title: 'someTitle'
+                Title: 'someTitle',
             };
             onEventCalled = false;
             onDialogCalled = false;