fix(desktop): run WSL commands with --exec so inline scripts are not pre-expanded (#49902)

packages/desktop/src/main/wsl/runtime.test.ts

@@ -0,0 +1,35 @@
+import { expect, test } from "bun:test"
+import { listInstalledWslDistros, probeWslRuntime, runWslSh, wslArgs } from "./runtime"
+
+test("wslArgs bypasses the distro default shell", () => {
+  expect(wslArgs(["sh", "-lc", 'printf "%s\\n" "$HOME"'], "Debian")).toEqual([
+    "-d",
+    "Debian",
+    "--exec",
+    "sh",
+    "-lc",
+    'printf "%s\\n" "$HOME"',
+  ])
+  expect(wslArgs(["bash", "-se"], "Debian", "root")).toEqual([
+    "-d",
+    "Debian",
+    "--user",
+    "root",
+    "--exec",
+    "bash",
+    "-se",
+  ])
+})
+
+// Exercise the real wsl.exe argv path: with `--`, WSL routes the command line through the distro's
+// default shell, which expands `$cli` to "" before `sh` runs the script (#48640).
+const distro =
+  process.platform === "win32" && (await probeWslRuntime()).available
+    ? (await listInstalledWslDistros().catch(() => [])).find((item) => item.isDefault)?.name
+    : undefined
+
+test.skipIf(!distro)("inline scripts keep their own variable expansion inside WSL", async () => {
+  const result = await runWslSh(['cli="from-script"', 'printf "%s\\n" "$cli"'].join("\n"), distro)
+  expect(result.code).toBe(0)
+  expect(result.stdout.trim()).toBe("from-script")
+})

packages/desktop/src/main/wsl/runtime.ts

@@ -38,7 +38,9 @@ const DEFAULT_WSL_TIMEOUT_MS = 20_000
 const DEFAULT_WSL_INSTALL_TIMEOUT_MS = 15 * 60_000
 
 export function wslArgs(args: string[], distro?: string | null, user?: string | null) {
-  return [...(distro ? ["-d", distro] : []), ...(user ? ["--user", user] : []), "--", ...args]
+  // `--` hands the command line to the distro's default shell, which expands `$VAR` and `$(...)`
+  // inside our inline scripts before `sh -lc` ever runs them. `--exec` runs the command directly.
+  return [...(distro ? ["-d", distro] : []), ...(user ? ["--user", user] : []), "--exec", ...args]
 }
 
 export function runWsl(args: string[], opts: RunWslOptions = {}) {