ts: Convert sub_store module to TypeScript.

We also upgrade @babel/preset-typescript to the latest version to
get support for constant enums.

package.json

@@ -9,7 +9,7 @@
     "@babel/core": "^7.5.5",
     "@babel/plugin-proposal-class-properties": "^7.5.5",
     "@babel/preset-env": "^7.5.5",
-    "@babel/preset-typescript": "^7.3.3",
+    "@babel/preset-typescript": "^7.15.0",
     "@babel/register": "^7.6.2",
     "@formatjs/intl": "^1.9.7",
     "@giphy/js-components": "^5.0.5",

static/js/sub_store.js

@@ -1,40 +0,0 @@
-import * as blueslip from "./blueslip";
-
-const subs_by_stream_id = new Map();
-
-export function get(stream_id) {
-    return subs_by_stream_id.get(stream_id);
-}
-
-export function validate_stream_ids(stream_ids) {
-    const good_ids = [];
-    const bad_ids = [];
-
-    for (const stream_id of stream_ids) {
-        if (subs_by_stream_id.has(stream_id)) {
-            good_ids.push(stream_id);
-        } else {
-            bad_ids.push(stream_id);
-        }
-    }
-
-    if (bad_ids.length > 0) {
-        blueslip.warn(`We have untracked stream_ids: ${bad_ids}`);
-    }
-
-    return good_ids;
-}
-
-export function clear() {
-    subs_by_stream_id.clear();
-}
-
-export function delete_sub(stream_id) {
-    subs_by_stream_id.delete(stream_id);
-}
-
-export function add_hydrated_sub(stream_id, sub) {
-    // The only code that should call this directly is
-    // in stream_data.js. Grep there to find callers.
-    subs_by_stream_id.set(stream_id, sub);
-}

static/js/sub_store.ts

@@ -0,0 +1,83 @@
+import * as blueslip from "./blueslip";
+
+export const enum StreamPostPolicy {
+    EVERYONE = 1,
+    ADMINS = 2,
+    RESTRICT_NEW_MEMBERS = 3,
+    MODERATORS = 4,
+}
+
+export const enum SubscriptionRole {
+    STREAM_ADMINISTRATOR = 20,
+    MEMBER = 50,
+}
+
+export type Stream = {
+    date_created: number;
+    description: string;
+    first_message_id: number | null;
+    history_public_to_subscribers: boolean;
+    invite_only: boolean;
+    is_announcement_only: boolean;
+    is_web_public: boolean;
+    message_retention_days: number | null;
+    name: string;
+    rendered_description: string;
+    stream_id: number;
+    stream_post_policy: StreamPostPolicy;
+};
+
+export type StreamSubscription = Stream & {
+    audible_notifications: boolean | null;
+    color: string;
+    desktop_notifications: boolean | null;
+    email_address: string;
+    email_notifications: boolean | null;
+    in_home_view: boolean;
+    is_muted: boolean;
+    pin_to_top: boolean;
+    push_notifications: boolean | null;
+    role: SubscriptionRole;
+    stream_weekly_traffic: number | null;
+    subscribers?: number[];
+    wildcard_mentions_notify: boolean | null;
+};
+
+const subs_by_stream_id = new Map<number, StreamSubscription>();
+
+export function get(stream_id: number): StreamSubscription | undefined {
+    return subs_by_stream_id.get(stream_id);
+}
+
+export function validate_stream_ids(stream_ids: number[]): number[] {
+    const good_ids = [];
+    const bad_ids = [];
+
+    for (const stream_id of stream_ids) {
+        if (subs_by_stream_id.has(stream_id)) {
+            good_ids.push(stream_id);
+        } else {
+            bad_ids.push(stream_id);
+        }
+    }
+
+    if (bad_ids.length > 0) {
+        blueslip.warn(`We have untracked stream_ids: ${bad_ids}`);
+    }
+
+    return good_ids;
+}
+
+export function clear(): void {
+    subs_by_stream_id.clear();
+}
+
+export function delete_sub(stream_id: number): void {
+    subs_by_stream_id.delete(stream_id);
+}
+
+export function add_hydrated_sub(stream_id: number, sub: StreamSubscription): void {
+    // The only code that should call this directly is
+    // in stream_data.js. Grep there to find callers.
+    subs_by_stream_id.set(stream_id, sub);
+}

yarn.lock

@@ -908,7 +908,7 @@
     "@babel/types" "^7.4.4"
     esutils "^2.0.2"
 
-"@babel/preset-typescript@^7.3.3":
+"@babel/preset-typescript@^7.15.0":
   version "7.15.0"
   resolved "https://registry.yarnpkg.com/@babel/preset-typescript/-/preset-typescript-7.15.0.tgz#e8fca638a1a0f64f14e1119f7fe4500277840945"
   integrity sha512-lt0Y/8V3y06Wq/8H/u0WakrqciZ7Fz7mwPDHWUJAXlABL5hiUG42BNlRXiELNjeWjO5rWmnNKlx+yzJvxezHow==