fix(connections): restore the test environment in place so SSH tests pass on Node 26

tests/electron/connections.test.ts

@@ -23,6 +23,7 @@ import { createBackend, type Backend } from "../../electron/create-backend.js";
 import { Tailscale } from "../../electron/local-server/tailscale.js";
 import { FakeTailscale } from "../helpers/fake-tailscale.js";
 import { InProcessLocalServer } from "../helpers/in-process-local-server.js";
+import { environmentRestorer } from "../helpers/restore-environment.js";
 import { adminRequest } from "../../server/admin.js";
 import { MasterKeyEncryption } from "../../server/master-key.js";
 import { createWispServer, type WispServer } from "../../server/wisp-server.js";
@@ -40,11 +41,11 @@ const silent = new StructuredLogger({ info: () => undefined, warn: () => undefin
 const fakeSsh = path.join(__dirname, "../fixtures/fake-ssh.cjs");
 const TEST_KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHRlc3R0ZXN0dGVzdHRlc3R0ZXN0dGVzdHRlc3Q= wisp@laptop";
 const cleanups: Array<() => Promise<void> | void> = [];
-const environment = { ...process.env };
+const restoreEnvironment = environmentRestorer();
 
 afterEach(async () => {
   for (const cleanup of cleanups.splice(0).reverse()) await cleanup();
-  process.env = { ...environment };
+  restoreEnvironment();
 });
 
 /** Sets up a new store with one Wisp, as the app does on a first run. */

tests/electron/ssh-test.test.ts

@@ -2,6 +2,7 @@ import path from "node:path";
 import { afterEach, describe, expect, it } from "vitest";
 import { sshTestFailure, testSshConnection } from "../../electron/connections/ssh-test.js";
 import type { SshConnectionProfile } from "../../shared/connections.js";
+import { environmentRestorer } from "../helpers/restore-environment.js";
 
 const profile: SshConnectionProfile = {
   id: "test",
@@ -13,9 +14,9 @@ const profile: SshConnectionProfile = {
   serverPort: 8787,
 };
 const sshPath = path.join(__dirname, "../fixtures/fake-ssh.cjs");
-const environment = { ...process.env };
+const restoreEnvironment = environmentRestorer();
 afterEach(() => {
-  process.env = { ...environment };
+  restoreEnvironment();
 });
 
 describe("SSH connection test", () => {

tests/electron/ssh-tunnel.test.ts

@@ -28,6 +28,7 @@ import {
 import { MasterKeyEncryption } from "../../server/master-key.js";
 import { createWispServer } from "../../server/wisp-server.js";
 import type { SshConnectionProfile, SshPromptView } from "../../shared/connections.js";
+import { environmentRestorer } from "../helpers/restore-environment.js";
 
 const TEST_KEY = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHRlc3R0ZXN0dGVzdHRlc3R0ZXN0dGVzdHRlc3Q= wisp@laptop";
 const fakeSsh = path.join(__dirname, "../fixtures/fake-ssh.cjs");
@@ -43,11 +44,11 @@ async function anotherService(): Promise<number> {
   cleanups.push(() => new Promise<void>((resolve) => service.close(() => resolve())));
   return (service.address() as AddressInfo).port;
 }
-const environment = { ...process.env };
+const restoreEnvironment = environmentRestorer();
 
 afterEach(async () => {
   for (const cleanup of cleanups.splice(0).reverse()) await cleanup();
-  process.env = { ...environment };
+  restoreEnvironment();
 });
 
 const profile = (serverPort: number): SshConnectionProfile => ({

tests/helpers/restore-environment.ts

@@ -0,0 +1,12 @@
+/**
+ * Remembers `process.env` and returns a function that puts it back. It changes
+ * the object in place because, from Node 26, child processes do not see
+ * variables set on an object assigned to `process.env`.
+ */
+export function environmentRestorer(): () => void {
+  const environment = { ...process.env };
+  return () => {
+    for (const name of Object.keys(process.env)) if (!(name in environment)) delete process.env[name];
+    Object.assign(process.env, environment);
+  };
+}