feat: allow users to define environment shape with zod

package.json

@@ -20,7 +20,8 @@
     "env-var": "7.4.1",
     "keyv": "4.5.3",
     "open-graph-scraper": "6.2.2",
-    "param-case": "3.0.4"
+    "param-case": "3.0.4",
+    "zod": "3.22.2"
   },
   "devDependencies": {
     "@types/node": "20.5.8",

src/config.ts

@@ -5,7 +5,6 @@ export const config = {
     token: env.get('DISCORD_TOKEN').required().asString(),
     clientId: env.get('DISCORD_CLIENT_ID').required().asString(),
     guildId: env.get('DISCORD_GUILD_ID').required().asString(),
-    coolLinksChannelId: env.get('COOL_LINKS_CHANNEL_ID').required().asString(),
   },
   redis: {
     url: env.get('REDIS_URL').required().asString(),

src/core/env.ts

@@ -0,0 +1,25 @@
+import { z } from 'zod';
+
+import type { BotModule } from '../types/bot';
+
+export let allEnvSchemas = z.object({});
+export const getEnv = () => process.env as z.infer<typeof allEnvSchemas>;
+
+export const loadEnvirontmentVariables = (modules: Record<string, BotModule>): void => {
+  const modulesEnv = Object.values(modules)
+    .map((module) => 'env' in module && module.env)
+    .filter(<T>(env: T): env is Exclude<T, false> => Boolean(env))
+    .reduce((acc, currentEnv) => {
+      Object.keys(currentEnv).forEach((key) => {
+        if (Object.keys(acc).includes(key)) {
+          throw new Error(`Duplicate environment variable found: ${key}`);
+        }
+      });
+      return { ...acc, ...currentEnv };
+    });
+
+  Object.entries(modulesEnv).forEach(([key, schema]) => {
+    allEnvSchemas = allEnvSchemas.extend({ [key]: schema });
+    schema.parse(process.env[key]);
+  });
+};

src/modules/coolLinksManagement/coolLinksManagement.module.ts

@@ -1,7 +1,8 @@
 import { MessageType, ThreadAutoArchiveDuration } from 'discord.js';
 import ogs from 'open-graph-scraper';
+import { z } from 'zod';
 
-import { config } from '../../config';
+import { getEnv } from '../../core/env';
 import { isASocialNetworkUrl } from '../../helpers/regex.helper';
 import type { BotModule } from '../../types/bot';
 import { getPageSummary } from './summarizeCoolPages';
@@ -33,12 +34,16 @@ const getThreadNameFromOpenGraph = async (url: string): Promise<string | null> =
 const youtubeUrlRegex = new RegExp('^(https?)?(://)?(www.)?(m.)?((youtube.com)|(youtu.be))');
 
 export const coolLinksManagement: BotModule = {
+  env: {
+    COOL_LINKS_CHANNEL_ID: z.string().nonempty(),
+  },
   eventHandlers: {
     messageCreate: async (message) => {
+      const env = getEnv();
       if (
         message.author.bot ||
         message.type !== MessageType.Default ||
-        message.channelId !== config.discord.coolLinksChannelId
+        message.channelId !== env['COOL_LINKS_CHANNEL_ID']
       ) {
         return;
       }

src/types/bot.ts

@@ -3,6 +3,7 @@ import type {
   ClientEvents,
   RESTPostAPIChatInputApplicationCommandsJSONBody,
 } from 'discord.js';
+import type { ZodTypeAny } from 'zod';
 
 type slashCommandHandler = (
   interaction: ChatInputCommandInteraction<'cached' | 'raw'>,
@@ -18,6 +19,9 @@ export type BotCommand = {
 };
 
 export type BotModule = {
+  env?: {
+    [key: string]: ZodTypeAny;
+  };
   slashCommands?: Array<BotCommand>;
   eventHandlers?: {
     [key in keyof ClientEvents]?: EventHandler<key>;