feat: add stripe webhooks (#4)

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- [x] I have pinned the dependencies to a specific patch version.

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### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
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Reviewed-on: #4
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/utils/errorHandler.ts

@@ -0,0 +1,32 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import { sendDiscord } from "../modules/discord.js";
+import { sendMail } from "../modules/sendMail.js";
+
+/**
+ * Forwards an error to the Discord webhook and email.
+ * @param error - The error to forward.
+ * @param context - The context in which the error occurred, for logging purposes.
+ */
+export const errorHandler = async(
+  error: unknown,
+  context: string,
+): Promise<void> => {
+  if (error instanceof Error) {
+    await sendDiscord(
+      `[ERROR] ${context}: ${error.message}`,
+      JSON.stringify(error, null, 2),
+    );
+    await sendMail(
+      `[ERROR] ${context}: ${error.message}`,
+      JSON.stringify(error, null, 2),
+    );
+    return;
+  }
+  await sendDiscord(`[ERROR] ${context}`, JSON.stringify(error, null, 2));
+  await sendMail(`[ERROR] ${context}`, JSON.stringify(error, null, 2));
+};