fix: clarify check setup requirements

Return an actionable 404 when /check cannot find the scheduler repository record, and document that the app must be installed before configuration validation.

Fixes #658

Author: coleleavitt

README.md

@@ -115,10 +115,10 @@ to yours using **hard reset** periodically. You can also manually
    conflictLabel: "merge-conflict" # Optional, on merge conflict assign a custom label, Default: merge-conflict
    ```
 
-4. Go to `https://pull.git.ci/check/${owner}/${repo}` to validate your
-   `.github/pull.yml`.
-5. Install
+4. Install
    **[<img src="https://prod.download/pull-18h-svg" valign="bottom"/> Pull app][pull-app]**.
+5. Go to `https://pull.git.ci/check/${owner}/${repo}` to validate your
+   `.github/pull.yml`.
 
 ### Trigger Manually
 

src/router/repo-handler.ts

@@ -2,6 +2,7 @@ import type { Request, Response } from "express";
 import type { Probot } from "probot";
 import { appConfig } from "@/src/configs/app-config.ts";
 import { getPullConfig } from "@/src/utils/get-pull-config.ts";
+import { missingRepositoryResponse } from "@/src/router/repo-response.ts";
 import {
   createSchedulerService,
   JobPriority,
@@ -21,8 +22,9 @@ function getRepoHandlers(
       const repoRecord = await RepositoryModel.findOne({ full_name });
 
       if (!repoRecord) {
-        app.log.error({ full_name }, `❌ Repo record not found`);
-        throw new Error(`❌ Repo record not found`);
+        app.log.warn({ full_name }, "Repository is not registered");
+        const response = missingRepositoryResponse(full_name);
+        return res.status(response.statusCode).json(response.body);
       }
 
       const {

src/router/repo-response.test.ts

@@ -0,0 +1,13 @@
+import { assertEquals } from "@std/assert";
+import { missingRepositoryResponse } from "@/src/router/repo-response.ts";
+
+Deno.test("missing repository response explains installation requirement", () => {
+  assertEquals(missingRepositoryResponse("dockur/zima"), {
+    statusCode: 404,
+    body: {
+      status: "error",
+      message:
+        "Repository 'dockur/zima' is not registered. Install the Pull GitHub App on this repository before checking its configuration.",
+    },
+  });
+});

src/router/repo-response.ts

@@ -0,0 +1,10 @@
+export function missingRepositoryResponse(fullName: string) {
+  return {
+    statusCode: 404,
+    body: {
+      status: "error",
+      message:
+        `Repository '${fullName}' is not registered. Install the Pull GitHub App on this repository before checking its configuration.`,
+    },
+  } as const;
+}