feat: vendor permission system source

pi-permission-system/test/safe-system-paths.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, test } from "vitest";
+
+import { isSafeSystemPath, SAFE_SYSTEM_PATHS } from "#src/safe-system-paths";
+
+describe("SAFE_SYSTEM_PATHS", () => {
+  test("contains /dev/null, /dev/stdin, /dev/stdout, /dev/stderr", () => {
+    expect(SAFE_SYSTEM_PATHS.has("/dev/null")).toBe(true);
+    expect(SAFE_SYSTEM_PATHS.has("/dev/stdin")).toBe(true);
+    expect(SAFE_SYSTEM_PATHS.has("/dev/stdout")).toBe(true);
+    expect(SAFE_SYSTEM_PATHS.has("/dev/stderr")).toBe(true);
+  });
+});
+
+describe("isSafeSystemPath", () => {
+  test("returns true for /dev/null", () => {
+    expect(isSafeSystemPath("/dev/null")).toBe(true);
+  });
+
+  test("returns true for /dev/stdin", () => {
+    expect(isSafeSystemPath("/dev/stdin")).toBe(true);
+  });
+
+  test("returns true for /dev/stdout", () => {
+    expect(isSafeSystemPath("/dev/stdout")).toBe(true);
+  });
+
+  test("returns true for /dev/stderr", () => {
+    expect(isSafeSystemPath("/dev/stderr")).toBe(true);
+  });
+
+  test("returns false for an arbitrary absolute path", () => {
+    expect(isSafeSystemPath("/etc/passwd")).toBe(false);
+  });
+
+  test("returns false for a path prefixed with a safe system path", () => {
+    expect(isSafeSystemPath("/dev/null/subdir")).toBe(false);
+  });
+
+  test("returns false for an empty string", () => {
+    expect(isSafeSystemPath("")).toBe(false);
+  });
+
+  test("returns false for a relative path", () => {
+    expect(isSafeSystemPath("dev/null")).toBe(false);
+  });
+});