eslint: Fix @typescript-eslint/prefer-nullish-coalescing.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

web/src/blueslip.ts

@@ -89,7 +89,7 @@ export function warn(msg: string, more_info?: unknown): void {
 export function error(msg: string, more_info?: object | undefined, original_error?: unknown): void {
     // Log the Sentry error before the console warning, so we don't
     // end up with a doubled message in the Sentry logs.
-    Sentry.setContext("more_info", more_info === undefined ? null : more_info);
+    Sentry.setContext("more_info", more_info ?? null);
 
     // Note that original_error could be of any type, because you can "raise"
     // any type -- something we do see in practice with the error

web/src/browser_history.ts

@@ -82,6 +82,7 @@ export function update(new_hash: string): void {
 export function exit_overlay(): void {
     if (hash_parser.is_overlay_hash(window.location.hash) && !state.changing_hash) {
         ui_util.blur_active_element();
+        // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
         const new_hash = state.hash_before_overlay || `#${user_settings.web_home_view}`;
         update(new_hash);
     }

web/src/compose_call.ts

@@ -35,7 +35,7 @@ export function compute_show_audio_chat_button(): boolean {
     const available_providers = page_params.realm_available_video_chat_providers;
     if (
         (available_providers.jitsi_meet &&
-            get_jitsi_server_url() &&
+            get_jitsi_server_url() !== null &&
             page_params.realm_video_chat_provider === available_providers.jitsi_meet.id) ||
         (available_providers.zoom &&
             page_params.realm_video_chat_provider === available_providers.zoom.id)

web/src/compose_state.ts

@@ -104,7 +104,7 @@ export function stream_id(): number | undefined {
 export function stream_name(): string {
     const stream_id = selected_recipient_id;
     if (typeof stream_id === "number") {
-        return sub_store.maybe_get_stream_name(stream_id) || "";
+        return sub_store.maybe_get_stream_name(stream_id) ?? "";
     }
     return "";
 }

web/src/message_store.ts

@@ -194,7 +194,7 @@ export function get_pm_full_names(message: Message): string {
 }
 
 export function set_message_booleans(message: Message): void {
-    const flags = message.flags || [];
+    const flags = message.flags ?? [];
 
     function convert_flag(flag_name: string): boolean {
         return flags.includes(flag_name);

web/src/overlays.ts

@@ -81,7 +81,7 @@ export function open_overlay(opts: OverlayOptions): void {
         return;
     }
 
-    if (active_overlay || open_overlay_name) {
+    if (active_overlay !== undefined || open_overlay_name) {
         blueslip.error("Programming error - trying to open overlay before closing other", {
             name: opts.name,
             open_overlay_name,

web/src/people.ts

@@ -190,7 +190,7 @@ export function get_bot_owner_user(user: User & {is_bot: true}): User | undefine
 
 export function can_admin_user(user: User): boolean {
     return (
-        (user.is_bot && user.bot_owner_id && user.bot_owner_id === page_params.user_id) ||
+        (user.is_bot && user.bot_owner_id !== null && user.bot_owner_id === page_params.user_id) ||
         is_my_user_id(user.user_id)
     );
 }

web/src/presence.ts

@@ -75,8 +75,8 @@ export function status_from_raw(raw: RawPresence): PresenceStatus {
     /* Mark users as offline after this many seconds since their last checkin, */
     const offline_threshold_secs = page_params.server_presence_offline_threshold_seconds;
 
-    function age(timestamp?: number): number {
-        return raw.server_timestamp - (timestamp || 0);
+    function age(timestamp = 0): number {
+        return raw.server_timestamp - timestamp;
     }
 
     const active_timestamp = raw.active_timestamp;
@@ -84,7 +84,7 @@ export function status_from_raw(raw: RawPresence): PresenceStatus {
 
     let last_active: number | undefined;
     if (active_timestamp !== undefined || idle_timestamp !== undefined) {
-        last_active = Math.max(active_timestamp || 0, idle_timestamp || 0);
+        last_active = Math.max(active_timestamp ?? 0, idle_timestamp ?? 0);
     }
 
     /*
@@ -141,18 +141,18 @@ export function update_info_from_event(
             server_timestamp: 1585745140
         }
     */
-    const raw = raw_info.get(user_id) || {
+    const raw = raw_info.get(user_id) ?? {
         server_timestamp: 0,
     };
 
     raw.server_timestamp = server_timestamp;
 
     for (const rec of Object.values(info)) {
-        if (rec.status === "active" && rec.timestamp > (raw.active_timestamp || 0)) {
+        if (rec.status === "active" && rec.timestamp > (raw.active_timestamp ?? 0)) {
             raw.active_timestamp = rec.timestamp;
         }
 
-        if (rec.status === "idle" && rec.timestamp > (raw.idle_timestamp || 0)) {
+        if (rec.status === "idle" && rec.timestamp > (raw.idle_timestamp ?? 0)) {
             raw.idle_timestamp = rec.timestamp;
         }
     }

web/src/settings_emoji.ts

@@ -130,7 +130,7 @@ export function populate_emoji(): void {
                     name: item.name,
                     display_name: item.name.replaceAll("_", " "),
                     source_url: item.source_url,
-                    author: item.author || "",
+                    author: item.author ?? "",
                     can_delete_emoji: can_delete_emoji(item),
                 },
             });