Improve permission utils, make them bigint-aware

backend/src/utils/canReadChannel.ts

@@ -1,10 +1,7 @@
-import { Constants, GuildChannel } from "eris";
-import { hasChannelPermissions } from "./hasChannelPermissions";
+import { Constants, GuildChannel, Member } from "eris";
+import { memberHasChannelPermissions } from "./memberHasChannelPermissions";
+import { readChannelPermissions } from "./readChannelPermissions";
 
-export function canReadChannel(channel: GuildChannel, memberId: string) {
-  const channelPermissions = channel.permissionsOf(memberId);
-  return hasChannelPermissions(channelPermissions, [
-    Constants.Permissions.readMessages,
-    Constants.Permissions.readMessageHistory,
-  ]);
+export function canReadChannel(channel: GuildChannel, member: Member) {
+  return memberHasChannelPermissions(member, channel, readChannelPermissions);
 }

backend/src/utils/hasChannelPermissions.ts

@@ -1,17 +0,0 @@
-import { Constants, Permission } from "eris";
-
-export function hasChannelPermissions(channelPermissions: Permission, permissions: number | number[]) {
-  if (Boolean(channelPermissions.allow & Constants.Permissions.administrator)) {
-    return true;
-  }
-
-  if (!Array.isArray(permissions)) {
-    permissions = [permissions];
-  }
-
-  for (const permission of permissions) {
-    if (!(channelPermissions.allow & permission)) return false;
-  }
-
-  return true;
-}

backend/src/utils/hasDiscordPermissions.ts

@@ -0,0 +1,16 @@
+import { Constants, Permission } from "eris";
+
+/**
+ * @param resolvedPermissions A Permission object from e.g. GuildChannel#permissionsOf() or Member#permission
+ * @param requiredPermissions Bitmask of required permissions
+ */
+export function hasDiscordPermissions(resolvedPermissions: Permission, requiredPermissions: number | bigint) {
+  const allowedPermissions = BigInt(resolvedPermissions.allow);
+  const nRequiredPermissions = BigInt(requiredPermissions);
+
+  if (Boolean(allowedPermissions & BigInt(Constants.Permissions.administrator))) {
+    return true;
+  }
+
+  return Boolean(allowedPermissions & nRequiredPermissions);
+}

backend/src/utils/memberHasChannelPermissions.ts

@@ -1,8 +1,15 @@
 import { Constants, GuildChannel, Member, Permission } from "eris";
 import { PluginData } from "knub";
-import { hasChannelPermissions } from "./hasChannelPermissions";
+import { hasDiscordPermissions } from "./hasDiscordPermissions";
 
-export function memberHasChannelPermissions(member: Member, channel: GuildChannel, permissions: number | number[]) {
+/**
+ * @param requiredPermissions Bitmask of required permissions
+ */
+export function memberHasChannelPermissions(
+  member: Member,
+  channel: GuildChannel,
+  requiredPermissions: number | bigint,
+) {
   const memberChannelPermissions = channel.permissionsOf(member.id);
-  return hasChannelPermissions(memberChannelPermissions, permissions);
+  return hasDiscordPermissions(memberChannelPermissions, requiredPermissions);
 }

backend/src/utils/readChannelPermissions.ts

@@ -0,0 +1,7 @@
+import { Constants } from "eris";
+
+/**
+ * Bitmask of permissions required to read messages in a channel
+ */
+export const readChannelPermissions =
+  BigInt(Constants.Permissions.readMessages) | BigInt(Constants.Permissions.readMessageHistory);

backend/src/utils/verifyPermissions.ts

@@ -0,0 +1,54 @@
+import { Constants, Permission } from "eris";
+import { PluginData } from "knub";
+import { hasDiscordPermissions } from "./hasDiscordPermissions";
+import { LogsPlugin } from "../plugins/Logs/LogsPlugin";
+import { LogType } from "../data/LogType";
+
+const defaultErrorText = `Missing permissions.`;
+
+const camelCaseToTitleCase = str =>
+  str
+    .replace(/([a-z])([A-Z])/g, "$1 $2")
+    .split(" ")
+    .map(w => w[0].toUpperCase() + w.slice(1))
+    .join(" ");
+
+const permissionNumberToName: Map<bigint, string> = new Map();
+for (const key in Constants.Permissions) {
+  permissionNumberToName.set(BigInt(Constants.Permissions[key]), camelCaseToTitleCase(key));
+}
+
+/**
+ *
+ * @param resolvedPermissions A Permission object from e.g. GuildChannel#permissionsOf() or Member#permission
+ * @param requiredPermissions Bitmask of required permissions
+ * @param errorText Custom error text
+ */
+export function verifyPermissions(
+  pluginData: PluginData<any>,
+  resolvedPermissions: Permission,
+  requiredPermissions: number | bigint,
+  errorText?: string,
+) {
+  const nRequiredPermissions = BigInt(requiredPermissions);
+
+  if (!hasDiscordPermissions(resolvedPermissions, nRequiredPermissions)) {
+    const requiredPermissionNames = [];
+    for (const [permissionNumber, permissionName] of permissionNumberToName.entries()) {
+      if (nRequiredPermissions & permissionNumber) {
+        requiredPermissionNames.push(permissionName);
+      }
+    }
+
+    const logs = pluginData.getPlugin(LogsPlugin);
+    logs.log(LogType.BOT_ALERT, {
+      body: `${errorText ||
+        defaultErrorText} Please ensure I have the following permissions: **${requiredPermissionNames.join(
+        "**, **",
+      )}**`.trim(),
+    });
+    return false;
+  }
+
+  return true;
+}