refactor(media): unify safe local file reads

src/infra/fs-safe.test.ts

@@ -0,0 +1,99 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { SafeOpenError, openFileWithinRoot, readLocalFileSafely } from "./fs-safe.js";
+
+const tempDirs: string[] = [];
+
+async function makeTempDir(prefix: string): Promise<string> {
+  const dir = await fs.mkdtemp(path.join(os.tmpdir(), prefix));
+  tempDirs.push(dir);
+  return dir;
+}
+
+afterEach(async () => {
+  await Promise.all(tempDirs.splice(0).map((dir) => fs.rm(dir, { recursive: true, force: true })));
+});
+
+describe("fs-safe", () => {
+  it("reads a local file safely", async () => {
+    const dir = await makeTempDir("openclaw-fs-safe-");
+    const file = path.join(dir, "payload.txt");
+    await fs.writeFile(file, "hello");
+
+    const result = await readLocalFileSafely({ filePath: file });
+    expect(result.buffer.toString("utf8")).toBe("hello");
+    expect(result.stat.size).toBe(5);
+    expect(result.realPath).toContain("payload.txt");
+  });
+
+  it("rejects directories", async () => {
+    const dir = await makeTempDir("openclaw-fs-safe-");
+    await expect(readLocalFileSafely({ filePath: dir })).rejects.toMatchObject({
+      code: "not-file",
+    });
+  });
+
+  it("enforces maxBytes", async () => {
+    const dir = await makeTempDir("openclaw-fs-safe-");
+    const file = path.join(dir, "big.bin");
+    await fs.writeFile(file, Buffer.alloc(8));
+
+    await expect(readLocalFileSafely({ filePath: file, maxBytes: 4 })).rejects.toMatchObject({
+      code: "too-large",
+    });
+  });
+
+  it.runIf(process.platform !== "win32")("rejects symlinks", async () => {
+    const dir = await makeTempDir("openclaw-fs-safe-");
+    const target = path.join(dir, "target.txt");
+    const link = path.join(dir, "link.txt");
+    await fs.writeFile(target, "target");
+    await fs.symlink(target, link);
+
+    await expect(readLocalFileSafely({ filePath: link })).rejects.toMatchObject({
+      code: "symlink",
+    });
+  });
+
+  it("blocks traversal outside root", async () => {
+    const root = await makeTempDir("openclaw-fs-safe-root-");
+    const outside = await makeTempDir("openclaw-fs-safe-outside-");
+    const file = path.join(outside, "outside.txt");
+    await fs.writeFile(file, "outside");
+
+    await expect(
+      openFileWithinRoot({
+        rootDir: root,
+        relativePath: path.join("..", path.basename(outside), "outside.txt"),
+      }),
+    ).rejects.toMatchObject({ code: "invalid-path" });
+  });
+
+  it.runIf(process.platform !== "win32")("blocks symlink escapes under root", async () => {
+    const root = await makeTempDir("openclaw-fs-safe-root-");
+    const outside = await makeTempDir("openclaw-fs-safe-outside-");
+    const target = path.join(outside, "outside.txt");
+    const link = path.join(root, "link.txt");
+    await fs.writeFile(target, "outside");
+    await fs.symlink(target, link);
+
+    await expect(
+      openFileWithinRoot({
+        rootDir: root,
+        relativePath: "link.txt",
+      }),
+    ).rejects.toMatchObject({ code: "invalid-path" });
+  });
+
+  it("returns not-found for missing files", async () => {
+    const dir = await makeTempDir("openclaw-fs-safe-");
+    const missing = path.join(dir, "missing.txt");
+
+    await expect(readLocalFileSafely({ filePath: missing })).rejects.toBeInstanceOf(SafeOpenError);
+    await expect(readLocalFileSafely({ filePath: missing })).rejects.toMatchObject({
+      code: "not-found",
+    });
+  });
+});