From ffa27ddcbc32275a333a1408b2eb7f6a5f68b3ca Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 15 Feb 2026 04:32:55 +0000
Subject: [PATCH] refactor(update): dedupe package manager detection

---
 src/infra/detect-package-manager.ts | 29 +++++++++++++++++++++++++++++
 src/infra/update-check.ts           | 24 ++----------------------
 src/infra/update-runner.ts          | 24 ++----------------------
 3 files changed, 33 insertions(+), 44 deletions(-)
 create mode 100644 src/infra/detect-package-manager.ts

diff --git a/src/infra/detect-package-manager.ts b/src/infra/detect-package-manager.ts
new file mode 100644
index 000000000..f1f96180c
--- /dev/null
+++ b/src/infra/detect-package-manager.ts
@@ -0,0 +1,29 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+
+export type DetectedPackageManager = "pnpm" | "bun" | "npm";
+
+export async function detectPackageManager(root: string): Promise<DetectedPackageManager | null> {
+  try {
+    const raw = await fs.readFile(path.join(root, "package.json"), "utf-8");
+    const parsed = JSON.parse(raw) as { packageManager?: string };
+    const pm = parsed?.packageManager?.split("@")[0]?.trim();
+    if (pm === "pnpm" || pm === "bun" || pm === "npm") {
+      return pm;
+    }
+  } catch {
+    // ignore
+  }
+
+  const files = await fs.readdir(root).catch((): string[] => []);
+  if (files.includes("pnpm-lock.yaml")) {
+    return "pnpm";
+  }
+  if (files.includes("bun.lockb")) {
+    return "bun";
+  }
+  if (files.includes("package-lock.json")) {
+    return "npm";
+  }
+  return null;
+}
diff --git a/src/infra/update-check.ts b/src/infra/update-check.ts
index 8525f53bf..d20621039 100644
--- a/src/infra/update-check.ts
+++ b/src/infra/update-check.ts
@@ -2,6 +2,7 @@ import fs from "node:fs/promises";
 import path from "node:path";
 import { runCommandWithTimeout } from "../process/exec.js";
 import { fetchWithTimeout } from "../utils/fetch-timeout.js";
+import { detectPackageManager as detectPackageManagerImpl } from "./detect-package-manager.js";
 import { parseSemver } from "./runtime-guard.js";
 import { channelToNpmTag, type UpdateChannel } from "./update-channels.js";
 
@@ -58,28 +59,7 @@ async function exists(p: string): Promise<boolean> {
 }
 
 async function detectPackageManager(root: string): Promise<PackageManager> {
-  try {
-    const raw = await fs.readFile(path.join(root, "package.json"), "utf-8");
-    const parsed = JSON.parse(raw) as { packageManager?: string };
-    const pm = parsed?.packageManager?.split("@")[0]?.trim();
-    if (pm === "pnpm" || pm === "bun" || pm === "npm") {
-      return pm;
-    }
-  } catch {
-    // ignore
-  }
-
-  const files = await fs.readdir(root).catch((): string[] => []);
-  if (files.includes("pnpm-lock.yaml")) {
-    return "pnpm";
-  }
-  if (files.includes("bun.lockb")) {
-    return "bun";
-  }
-  if (files.includes("package-lock.json")) {
-    return "npm";
-  }
-  return "unknown";
+  return (await detectPackageManagerImpl(root)) ?? "unknown";
 }
 
 async function detectGitRoot(root: string): Promise<string | null> {
diff --git a/src/infra/update-runner.ts b/src/infra/update-runner.ts
index ac774a141..46bbf8a19 100644
--- a/src/infra/update-runner.ts
+++ b/src/infra/update-runner.ts
@@ -6,6 +6,7 @@ import {
   resolveControlUiDistIndexHealth,
   resolveControlUiDistIndexPathForRoot,
 } from "./control-ui-assets.js";
+import { detectPackageManager as detectPackageManagerImpl } from "./detect-package-manager.js";
 import { trimLogTail } from "./restart-sentinel.js";
 import {
   channelToNpmTag,
@@ -254,28 +255,7 @@ async function findPackageRoot(candidates: string[]) {
 }
 
 async function detectPackageManager(root: string) {
-  try {
-    const raw = await fs.readFile(path.join(root, "package.json"), "utf-8");
-    const parsed = JSON.parse(raw) as { packageManager?: string };
-    const pm = parsed?.packageManager?.split("@")[0]?.trim();
-    if (pm === "pnpm" || pm === "bun" || pm === "npm") {
-      return pm;
-    }
-  } catch {
-    // ignore
-  }
-
-  const files = await fs.readdir(root).catch((): string[] => []);
-  if (files.includes("pnpm-lock.yaml")) {
-    return "pnpm";
-  }
-  if (files.includes("bun.lockb")) {
-    return "bun";
-  }
-  if (files.includes("package-lock.json")) {
-    return "npm";
-  }
-  return "npm";
+  return (await detectPackageManagerImpl(root)) ?? "npm";
 }
 
 type RunStepOptions = {