typing: Convert module to TypeScript.

tools/test-js-with-node

@@ -248,7 +248,7 @@ EXEMPT_FILES = make_set(
         "web/src/topic_popover.js",
         "web/src/tutorial.js",
         "web/src/types.ts",
-        "web/src/typing.js",
+        "web/src/typing.ts",
         "web/src/typing_events.js",
         "web/src/ui_init.js",
         "web/src/ui_report.ts",

web/src/typing.ts

@@ -1,6 +1,7 @@
 import $ from "jquery";
 
 import * as typing_status from "../shared/src/typing_status";
+import type {Recipient} from "../shared/src/typing_status";
 
 import * as blueslip from "./blueslip";
 import * as channel from "./channel";
@@ -11,16 +12,26 @@ import * as people from "./people";
 import * as stream_data from "./stream_data";
 import {user_settings} from "./user_settings";
 
+type TypingAPIRequest = {op: "start" | "stop"} & (
+    | {
+          to: string;
+      }
+    | {
+          type: string;
+          stream_id: string;
+          topic: string;
+      }
+);
+
 // This module handles the outbound side of typing indicators.
 // We detect changes in the compose box and notify the server
 // when we are typing.  For the inbound side see typing_events.js.
 // See docs/subsystems/typing-indicators.md for more details.
 
-function send_typing_notification_ajax(data) {
-    channel.post({
+function send_typing_notification_ajax(data: TypingAPIRequest): void {
+    void channel.post({
         url: "/json/typing",
         data,
-        success() {},
         error(xhr) {
             if (xhr.readyState !== 0) {
                 blueslip.warn("Failed to send typing event: " + xhr.responseText);
@@ -29,7 +40,10 @@ function send_typing_notification_ajax(data) {
     });
 }
 
-function send_direct_message_typing_notification(user_ids_array, operation) {
+function send_direct_message_typing_notification(
+    user_ids_array: number[],
+    operation: "start" | "stop",
+): void {
     const data = {
         to: JSON.stringify(user_ids_array),
         op: operation,
@@ -37,7 +51,11 @@ function send_direct_message_typing_notification(user_ids_array, operation) {
     send_typing_notification_ajax(data);
 }
 
-function send_stream_typing_notification(stream_id, topic, operation) {
+function send_stream_typing_notification(
+    stream_id: number,
+    topic: string,
+    operation: "start" | "stop",
+): void {
     const data = {
         type: "stream",
         stream_id: JSON.stringify(stream_id),
@@ -47,7 +65,10 @@ function send_stream_typing_notification(stream_id, topic, operation) {
     send_typing_notification_ajax(data);
 }
 
-function send_typing_notification_based_on_message_type(to, operation) {
+function send_typing_notification_based_on_message_type(
+    to: Recipient,
+    operation: "start" | "stop",
+): void {
     if (to.message_type === "direct" && user_settings.send_private_typing_notifications) {
         send_direct_message_typing_notification(to.ids, operation);
     } else if (to.message_type === "stream" && user_settings.send_stream_typing_notifications) {
@@ -55,7 +76,7 @@ function send_typing_notification_based_on_message_type(to, operation) {
     }
 }
 
-function get_user_ids_array() {
+function get_user_ids_array(): number[] | null {
     const user_ids_string = compose_pm_pill.get_user_ids_string();
     if (user_ids_string === "") {
         return null;
@@ -64,7 +85,7 @@ function get_user_ids_array() {
     return people.user_ids_string_to_ids_array(user_ids_string);
 }
 
-function is_valid_conversation() {
+function is_valid_conversation(): boolean {
     const compose_empty = !compose_state.has_message_content();
     if (compose_empty) {
         return false;
@@ -73,29 +94,29 @@ function is_valid_conversation() {
     return true;
 }
 
-function get_current_time() {
+function get_current_time(): number {
     return Date.now();
 }
 
-function notify_server_start(to) {
+function notify_server_start(to: Recipient): void {
     send_typing_notification_based_on_message_type(to, "start");
 }
 
-function notify_server_stop(to) {
+function notify_server_stop(to: Recipient): void {
     send_typing_notification_based_on_message_type(to, "stop");
 }
 
-export function get_recipient() {
+export function get_recipient(): Recipient | null {
     const message_type = compose_state.get_message_type();
     if (message_type === "private") {
         return {
             message_type: "direct",
-            ids: get_user_ids_array(),
+            ids: get_user_ids_array()!,
         };
     }
     if (message_type === "stream") {
         const stream_name = compose_state.stream_name();
-        const stream_id = stream_data.get_stream_id(stream_name);
+        const stream_id = stream_data.get_stream_id(stream_name)!;
         const topic = compose_state.topic();
         return {
             message_type: "stream",
@@ -106,7 +127,7 @@ export function get_recipient() {
     return null;
 }
 
-export function initialize() {
+export function initialize(): void {
     const worker = {
         get_current_time,
         notify_server_start,