fix(e2e): encode multiline sandbox scripts

test/e2e-scenario/fixtures/clients/sandbox.ts

@@ -7,8 +7,8 @@ import { trustedShellCommand } from "../shell-probe.ts";
 import {
   artifactLabel,
   assertExitZero,
-  outputContainsSandbox,
   type CommandRunner,
+  outputContainsSandbox,
 } from "./command.ts";
 
 /**
@@ -42,12 +42,18 @@ export type TrustedSandboxShellScript = string & {
 };
 
 export function trustedSandboxShellScript(script: string): TrustedSandboxShellScript {
-  if (script.length === 0) {
-    throw new Error("sandbox shell script must not be empty");
+  if (script.length === 0 || script.includes("\0")) {
+    throw new Error("sandbox shell script must be non-empty and contain no NUL bytes");
   }
   return script as TrustedSandboxShellScript;
 }
 
+function sandboxShellArgument(script: TrustedSandboxShellScript): string {
+  if (!/[\r\n]/u.test(script)) return script;
+  const encoded = Buffer.from(script, "utf8").toString("base64");
+  return `eval "$(printf '%s' '${encoded}' | base64 -d)"`;
+}
+
 export class SandboxClient {
   private readonly runner: CommandRunner;
   private readonly openshellPath: string;
@@ -104,10 +110,13 @@ export class SandboxClient {
     options: ShellProbeRunOptions = {},
   ): Promise<ShellProbeResult> {
     validateSandboxName(name);
-    return this.openshell(["sandbox", "exec", "-n", name, "--", "sh", "-lc", script], {
-      artifactName: `sandbox-exec-shell-${name}`,
-      ...options,
-    });
+    return this.openshell(
+      ["sandbox", "exec", "-n", name, "--", "sh", "-lc", sandboxShellArgument(script)],
+      {
+        artifactName: `sandbox-exec-shell-${name}`,
+        ...options,
+      },
+    );
   }
 
   upload(

test/e2e-scenario/support-tests/e2e-clients.test.ts

@@ -402,8 +402,23 @@ describe("E2E fixture clients", () => {
     });
   });
 
+  it("encodes multiline shell scripts into an OpenShell-safe single argument", async () => {
+    const runner = new FakeRunner();
+    const sandbox = new SandboxClient(runner, { openshellPath: "openshell" });
+    const source = "set -e\nprintf 'ready\\n'\n";
+
+    await sandbox.execShell("assistant", trustedSandboxShellScript(source));
+
+    const argument = runner.calls[0]?.args.at(-1) ?? "";
+    expect(argument).not.toMatch(/[\r\n]/u);
+    const encoded = argument.match(/'([A-Za-z0-9+/=]+)' \| base64 -d/u)?.[1];
+    expect(encoded).toBeTruthy();
+    expect(Buffer.from(encoded ?? "", "base64").toString("utf8")).toBe(source);
+  });
+
   it("sandbox client requires trusted non-empty shell scripts", () => {
-    expect(() => trustedSandboxShellScript("")).toThrow(/must not be empty/);
+    expect(() => trustedSandboxShellScript("")).toThrow(/must be non-empty/);
+    expect(() => trustedSandboxShellScript("echo ready\0ignored")).toThrow(/no NUL bytes/);
     expectTypeOf<Parameters<SandboxClient["execShell"]>[1]>().not.toEqualTypeOf<string>();
   });