Refactor GitHub App installation error handling in code context hash endpoints. Introduced a dedicated assertion function to streamline error validation and improve logging for installation issues.

js/cf-api/endpoints/code-context-hash.ts

@@ -1,5 +1,6 @@
 import { prisma } from "@codeflash-ai/common"
 import { Request, Response } from "express"
+import { Octokit } from "@octokit/core"
 import { githubApp } from "../github/github-app.js"
 import { getInstallationOctokitByOwner, isUserCollaborator } from "../github/github-utils.js"
 import { userNickname } from "../auth0-mgmt.js"
@@ -16,6 +17,34 @@ import {
   githubInstallationError,
 } from "../exceptions/index.js"
 
+const GITHUB_APP_INSTALL_LINK = "https://github.com/apps/codeflash-ai/installations/select_target"
+
+/**
+ * Validates the installation octokit result and throws appropriate errors if it's an Error.
+ * Uses TypeScript assertion to narrow the type to Octokit on success.
+ */
+function assertInstallationOctokit(
+  octokit: Octokit | Error,
+  owner: string,
+  repo: string,
+  req: Request,
+): asserts octokit is Octokit {
+  if (!(octokit instanceof Error)) return
+
+  const repoPath = `${owner}/${repo}`
+  const errorMessage = octokit.message
+
+  if (errorMessage.includes("not installed")) {
+    logger.warn("GitHub App not installed on repository", req, {
+      repo: repoPath,
+      installationLink: GITHUB_APP_INSTALL_LINK,
+    })
+    throw githubInstallationNotFound(`${repoPath}. Please install the GitHub App at: ${GITHUB_APP_INSTALL_LINK}`)
+  } else {
+    throw githubInstallationError(errorMessage)
+  }
+}
+
 export async function is_code_being_optimized_again(req: Request, res: Response) {
   try {
     const { owner, repo, pr_number, code_contexts } = req.body
@@ -29,21 +58,7 @@ export async function is_code_being_optimized_again(req: Request, res: Response)
       throw unauthorized("")
     }
     const octokit = await getInstallationOctokitByOwner(githubApp, owner, repo, userId)
-    if (octokit instanceof Error) {
+    assertInstallationOctokit(octokit, owner, repo, req)
-      const errorMessage = octokit.message
-      if (errorMessage.includes("not installed")) {
-        const installationLink = "https://github.com/apps/codeflash-ai/installations/select_target"
-        logger.warn("GitHub App not installed on repository", req, {
-          repo: `${owner}/${repo}`,
-          installationLink,
-        })
-        throw githubInstallationNotFound(
-          `${owner}/${repo}. Please install the GitHub App at: ${installationLink}`,
-        )
-      } else {
-        throw githubInstallationError(errorMessage)
-      }
-    }
 
     // Check collaborator status with error handling
     try {
@@ -177,21 +192,7 @@ export async function add_optimized_code_context(req: Request, res: Response) {
     }
 
     const octokit = await getInstallationOctokitByOwner(githubApp, owner, repo, userId)
-    if (octokit instanceof Error) {
+    assertInstallationOctokit(octokit, owner, repo, req)
-      const errorMessage = octokit.message
-      if (errorMessage.includes("not installed")) {
-        const installationLink = "https://github.com/apps/codeflash-ai/installations/select_target"
-        logger.warn("GitHub App not installed on repository", req, {
-          repo: `${owner}/${repo}`,
-          installationLink,
-        })
-        throw githubInstallationNotFound(
-          `${owner}/${repo}. Please install the GitHub App at: ${installationLink}`,
-        )
-      } else {
-        throw githubInstallationError(errorMessage)
-      }
-    }
 
     // Check collaborator status with error handling
     try {