feat: Get follower ids (#278)

* feat: make box's contents can empty and add animated property

* Modify to original

* add to document

* feat: followers ids api

* 🔥 make function public

* remove wrap function

Co-authored-by: xingo xu <xingoxu@users.noreply.github.com>
Co-authored-by: xingoxu <xingoxu@gmail.com>

Author: louis70109

docs/api-reference/client.md

@@ -369,6 +369,19 @@ client.getGroupMemberIds('group_id').then((ids) => {
 })
 ```
 
+
+#### `getBotFollowersIds(): Promise<string[]>`
+
+It corresponds to the [Bot Followers IDs](https://developers.line.biz/en/reference/messaging-api/#get-follower-ids) API.
+
+*FYI: This feature is available only for verified or premium accounts.*
+
+``` js
+client.getBotFollowersIds().then((ids) => {
+  ids.forEach((id) => console.log(id));
+})
+```
+
 #### `leaveGroup(groupId: string): Promise<any>`
 
 It corresponds to the [Leave group](https://developers.line.biz/en/reference/messaging-api/#leave-group) API.

lib/client.ts

@@ -200,6 +200,23 @@ export default class Client {
     return this.getChatMemberIds("room", roomId);
   }
 
+  public async getBotFollowersIds(): Promise<string[]> {
+    let userIds: string[] = [];
+
+    let start: string;
+    do {
+      const res = await this.http.get<{ userIds: string[]; next?: string }>(
+        `${MESSAGING_API_PREFIX}/followers/ids`,
+        start ? { start } : null,
+      );
+      ensureJSON(res);
+      userIds = userIds.concat(res.userIds);
+      start = res.next;
+    } while (start);
+
+    return userIds;
+  }
+
   public async getGroupMembersCount(
     groupId: string,
   ): Promise<Types.MembersCountResponse> {

test/client.spec.ts

@@ -375,6 +375,12 @@ describe("client", () => {
     ]);
   });
 
+  it("getBotFollowersIds", async () => {
+    const scope = mockGet(MESSAGING_API_PREFIX, "/followers/ids");
+    const ids = await client.getBotFollowersIds();
+    equal(scope.isDone(), true);
+  });
+
   it("getGroupMembersCount", async () => {
     const groupId = "groupId";
     const scope = mockGet(