Parse gh app install callback with a discriminated union

Author: myftija

apps/webapp/app/routes/_app.github.callback/route.tsx

@@ -8,11 +8,22 @@ import { tryCatch } from "@trigger.dev/core";
 import { $replica } from "~/db.server";
 import { requireUser } from "~/services/session.server";
 
-const QuerySchema = z.object({
-  installation_id: z.coerce.number(),
-  setup_action: z.enum(["install", "update", "request"]),
-  state: z.string(),
-});
+const QuerySchema = z.discriminatedUnion("setup_action", [
+  z.object({
+    setup_action: z.literal("install"),
+    installation_id: z.coerce.number(),
+    state: z.string(),
+  }),
+  z.object({
+    setup_action: z.literal("update"),
+    installation_id: z.coerce.number(),
+    state: z.string(),
+  }),
+  z.object({
+    setup_action: z.literal("request"),
+    state: z.string(),
+  }),
+]);
 
 export async function loader({ request }: LoaderFunctionArgs) {
   const url = new URL(request.url);
@@ -28,14 +39,13 @@ export async function loader({ request }: LoaderFunctionArgs) {
     return redirectWithErrorMessage("/", request, "Failed to install GitHub App");
   }
 
-  const { installation_id, setup_action, state } = result.data;
+  const callbackData = result.data;
 
-  const sessionResult = await validateGitHubAppInstallSession(cookieHeader, state);
+  const sessionResult = await validateGitHubAppInstallSession(cookieHeader, callbackData.state);
 
   if (!sessionResult.valid) {
     logger.error("GitHub App callback with invalid session", {
-      state,
-      installation_id,
+      callbackData,
       error: sessionResult.error,
     });
 
@@ -63,10 +73,12 @@ export async function loader({ request }: LoaderFunctionArgs) {
     return redirectWithErrorMessage(redirectTo, request, "Failed to install GitHub App");
   }
 
-  switch (setup_action) {
+  switch (callbackData.setup_action) {
     case "install":
     case "update": {
-      const [error] = await tryCatch(linkGitHubAppInstallation(installation_id, organizationId));
+      const [error] = await tryCatch(
+        linkGitHubAppInstallation(callbackData.installation_id, organizationId)
+      );
 
       if (error) {
         logger.error("Failed to link GitHub App installation", {
@@ -82,14 +94,14 @@ export async function loader({ request }: LoaderFunctionArgs) {
       // This happens when a non-admin user requests installation
       // The installation_id won't be available until an admin approves
       logger.info("GitHub App installation requested, awaiting approval", {
-        state,
+        callbackData,
       });
 
       return redirectWithSuccessMessage(redirectTo, request, "GitHub App installation requested");
     }
 
     default:
-      setup_action satisfies never;
+      callbackData satisfies never;
       return redirectWithErrorMessage(redirectTo, request, "Failed to install GitHub App");
   }
 }