fix(service): support systemd 219 install cleanup

src/service.ts

@@ -2676,6 +2676,29 @@ type ServiceInstallCleanupOps = {
   stop: () => void;
 };
 
+/**
+ * Query whether systemd already knows the user service before install cleanup.
+ *
+ * Keep the property name in the output instead of using `systemctl --value`:
+ * CentOS 7's systemd 219 supports `-p LoadState` but not the later `--value`
+ * switch (#2866). Requiring the explicit `LoadState=` key also preserves the
+ * fail-closed boundary — empty, truncated, or unrelated output must not be
+ * mistaken for a confirmed absent unit.
+ */
+export function systemdInstallCleanupStatus(
+  deps: { show?: () => string } = {},
+): string | null {
+  const output = (deps.show ?? (() => sh(`systemctl --user show ${TASK} -p LoadState`)))();
+  const lines = output.replace(/\r/g, "").split("\n");
+  if (lines[lines.length - 1] === "") lines.pop();
+  const match = lines.length === 1
+    ? /^LoadState=(.+)$/.exec(lines[0] ?? "")
+    : null;
+  const loadState = match?.[1]?.trim().toLowerCase() ?? "";
+  if (!loadState) throw new Error("systemd service status could not be verified.");
+  return loadState === "not-found" ? null : loadState;
+}
+
 function platformOps(backend: ServiceBackend = "scheduler"): ServiceOps | null {
   if (process.platform === "darwin")
     return { install: installLaunchd, start: startLaunchd, stop: stopLaunchd, status: statusLaunchd, uninstall: uninstallLaunchd };
@@ -2745,17 +2768,12 @@ function platformServiceInstallCleanupOps(backend: ServiceBackend): ServiceInsta
   }
   if (process.platform === "linux") {
     return {
-      status: () => {
-        // `list-unit-files <name>` exits non-zero when the unit has never been
-        // installed, which made a clean first install look like an unknown manager
-        // failure. `show LoadState` gives us the tri-state we actually need: a
-        // healthy user manager returns `not-found` for a missing unit, while an
-        // unreachable/permission-denied manager still makes `sh()` throw and the
-        // caller therefore fails closed.
-        const loadState = sh(`systemctl --user show ${TASK} --property=LoadState --value`).trim().toLowerCase();
-        if (!loadState) throw new Error("systemd service status could not be verified.");
-        return loadState === "not-found" ? null : loadState;
-      },
+      // `list-unit-files <name>` exits non-zero when the unit has never been
+      // installed, which made a clean first install look like an unknown manager
+      // failure. `show LoadState` gives us the tri-state we actually need; the helper
+      // also keeps this compatible with systemd 219 without weakening fail-closed
+      // manager errors (#2866).
+      status: systemdInstallCleanupStatus,
       stop: () => { sh(`systemctl --user stop ${TASK}`); },
     };
   }

tests/systemd-install-cleanup-hardening.test.ts

@@ -1,13 +1,41 @@
 import { describe, expect, test } from "bun:test";
 import { readFileSync } from "node:fs";
 import { join } from "node:path";
+import { systemdInstallCleanupStatus } from "../src/service";
 
 const source = readFileSync(join(import.meta.dir, "../src/service.ts"), "utf8");
 
 describe("systemd install cleanup status hardening", () => {
   test("only treats literal not-found as confirmed unit absence", () => {
-    expect(source).toContain('if (!loadState) throw new Error("systemd service status could not be verified.");');
+    expect(systemdInstallCleanupStatus({ show: () => "LoadState=not-found\n" })).toBeNull();
+    expect(systemdInstallCleanupStatus({ show: () => "LoadState=loaded\n" })).toBe("loaded");
     expect(source).toContain('return loadState === "not-found" ? null : loadState;');
     expect(source).not.toContain('return !loadState || loadState === "not-found" ? null : loadState;');
   });
+
+  test("uses the key/value output supported by systemd 219", () => {
+    const start = source.indexOf("export function systemdInstallCleanupStatus");
+    const end = source.indexOf("function platformOps", start);
+    expect(start).toBeGreaterThanOrEqual(0);
+    expect(end).toBeGreaterThan(start);
+    const helper = source.slice(start, end);
+
+    expect(helper).toContain("systemctl --user show ${TASK} -p LoadState");
+    expect(helper).not.toContain("--value");
+  });
+
+  test("fails closed on missing, empty, or legacy bare-value output", () => {
+    for (const output of [
+      "",
+      "LoadState=\n",
+      "not-found\n",
+      "ActiveState=inactive\n",
+      "ActiveState=inactive\nLoadState=loaded\n",
+      "LoadState=loaded\nunexpected\n",
+      "LoadState=loaded\n\n",
+    ]) {
+      expect(() => systemdInstallCleanupStatus({ show: () => output }))
+        .toThrow("systemd service status could not be verified");
+    }
+  });
 });