fix: support native package verifier scratch

core/tests/module-package-verification.test.ts

@@ -1,4 +1,4 @@
-import { mkdtemp, readdir, rm, stat, writeFile } from "node:fs/promises";
+import { mkdir, mkdtemp, readdir, rm, stat, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import path from "node:path";
 import { afterEach, describe, expect, it } from "vitest";
@@ -48,6 +48,12 @@ async function archiveFile(options: PackageFixtureOptions = {}): Promise<{
   return { archivePath, sha256: fixture.sha256 };
 }
 
+async function executionScratch(): Promise<string> {
+  const directory = path.join(await scratch(), "execution");
+  await mkdir(directory);
+  return directory;
+}
+
 async function rejection(
   options: PackageFixtureOptions,
   code: ModulePackageVerificationErrorCode,
@@ -100,6 +106,52 @@ describe("Module Package v1 verification (ADR 0049)", () => {
     });
   });
 
+  it("uses an explicit execution scratch for pure JavaScript and cleans concurrent runs", async () => {
+    const { archivePath } = await archiveFile();
+    const executionScratchDirectory = await executionScratch();
+    const runs = Array.from({ length: 4 }, () =>
+      verifyModulePackage({ archivePath, executionScratchDirectory, platform }),
+    );
+    await expect(Promise.all(runs)).resolves.toHaveLength(4);
+    expect(await readdir(executionScratchDirectory)).toEqual([]);
+  });
+
+  it("cleans its execution scratch after a backend load failure", async () => {
+    const { archivePath } = await archiveFile({
+      serverSource:
+        'import "dependency-not-in-this-package";\nexport default { id: "example", version: "0.1.0" };\n',
+    });
+    const executionScratchDirectory = await executionScratch();
+    await expect(
+      verifyModulePackage({ archivePath, executionScratchDirectory, platform }),
+    ).rejects.toMatchObject({ code: "MODULE_PACKAGE_ENTRYPOINT_LOAD_FAILED" });
+    expect(await readdir(executionScratchDirectory)).toEqual([]);
+  });
+
+  it("reports a missing execution scratch as a verifier environment error", async () => {
+    const { archivePath } = await archiveFile();
+    const executionScratchDirectory = path.join(await scratch(), "missing");
+    await expect(
+      verifyModulePackage({ archivePath, executionScratchDirectory, platform }),
+    ).rejects.toMatchObject({
+      code: "MODULE_PACKAGE_VERIFIER_SCRATCH_UNAVAILABLE",
+      message:
+        "The verifier execution scratch directory is missing, not writable, or mounted noexec.",
+    });
+    await expect(stat(executionScratchDirectory)).rejects.toMatchObject({ code: "ENOENT" });
+  });
+
+  it("rejects an unsafe archive before consulting the execution scratch", async () => {
+    const { archivePath } = await archiveFile(
+      withEntry({ path: "example/../attacker-chosen", data: "x" }),
+    );
+    const executionScratchDirectory = path.join(await scratch(), "missing");
+    await expect(
+      verifyModulePackage({ archivePath, executionScratchDirectory, platform }),
+    ).rejects.toMatchObject({ code: "MODULE_PACKAGE_UNSAFE_PATH" });
+    await expect(stat(executionScratchDirectory)).rejects.toMatchObject({ code: "ENOENT" });
+  });
+
   it("extracts only a verified package, with normalized modes, into a new directory", async () => {
     const { archivePath } = await archiveFile();
     const target = path.join(await scratch(), "example");

core/tests/verify-module-package-cli.test.ts

@@ -3,6 +3,8 @@ import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { describe, expect, it } from "vitest";
 import {
+  MODULE_VERIFIER_SCRATCH_ENV,
+  moduleVerifierScratchDirectory,
   parseSha256File,
   parseVerifyModulePackageArguments,
   readModulePackagePlatform,
@@ -57,6 +59,21 @@ describe("verify-module-package digest files", () => {
   });
 });
 
+describe("verify-module-package execution scratch", () => {
+  it("accepts an absolute operator-configured directory and otherwise leaves the library default", () => {
+    expect(moduleVerifierScratchDirectory({})).toBeUndefined();
+    expect(
+      moduleVerifierScratchDirectory({ [MODULE_VERIFIER_SCRATCH_ENV]: "/run/ekklesia-verifier" }),
+    ).toBe("/run/ekklesia-verifier");
+  });
+
+  it.each(["", "relative/path"])("refuses the invalid configured path %j", (configured) => {
+    expect(() =>
+      moduleVerifierScratchDirectory({ [MODULE_VERIFIER_SCRATCH_ENV]: configured }),
+    ).toThrow(`${MODULE_VERIFIER_SCRATCH_ENV} must be an absolute path.`);
+  });
+});
+
 describe("verify-module-package platform facts", () => {
   it("reads this platform's versions and its transitional database runtime from the repository", async () => {
     const root = JSON.parse(await readFile(path.join(repositoryRoot, "package.json"), "utf8"));