Add structured Discord attachments

src/outbound-attachments.test.ts

@@ -0,0 +1,149 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+import { afterEach, describe, expect, it } from 'vitest';
+
+import { validateOutboundAttachments } from './outbound-attachments.js';
+
+const ONE_PIXEL_PNG = Buffer.from(
+  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/p9sAAAAASUVORK5CYII=',
+  'base64',
+);
+
+const cleanupDirs: string[] = [];
+
+function makeTempDir(baseDir: string, prefix: string): string {
+  const dir = fs.mkdtempSync(path.join(baseDir, prefix));
+  cleanupDirs.push(dir);
+  return dir;
+}
+
+function writeFile(
+  dir: string,
+  name: string,
+  content: Buffer | string,
+): string {
+  const filePath = path.join(dir, name);
+  fs.writeFileSync(filePath, content);
+  return filePath;
+}
+
+afterEach(() => {
+  for (const dir of cleanupDirs.splice(0)) {
+    fs.rmSync(dir, { force: true, recursive: true });
+  }
+});
+
+describe('validateOutboundAttachments', () => {
+  it('accepts real image files under default attachment directories', () => {
+    const dir = makeTempDir(os.tmpdir(), 'ejclaw-attachment-');
+    const imagePath = writeFile(dir, 'screenshot.png', ONE_PIXEL_PNG);
+
+    const result = validateOutboundAttachments([
+      {
+        path: imagePath,
+        name: '../unsafe-name.png',
+        mime: 'image/png',
+      },
+    ]);
+
+    expect(result.rejected).toEqual([]);
+    expect(result.files).toEqual([
+      {
+        attachment: fs.realpathSync(imagePath),
+        name: 'unsafe-name.png',
+      },
+    ]);
+  });
+
+  it('requires workspace paths to be explicitly allowlisted', () => {
+    const dir = makeTempDir(process.cwd(), '.ejclaw-attachment-');
+    const imagePath = writeFile(dir, 'workspace-shot.png', ONE_PIXEL_PNG);
+
+    expect(validateOutboundAttachments([{ path: imagePath }])).toEqual({
+      files: [],
+      rejected: [{ path: imagePath, reason: 'outside-allowed-dirs' }],
+    });
+
+    const allowed = validateOutboundAttachments([{ path: imagePath }], {
+      baseDirs: [dir],
+    });
+
+    expect(allowed.rejected).toEqual([]);
+    expect(allowed.files).toEqual([
+      {
+        attachment: fs.realpathSync(imagePath),
+        name: 'workspace-shot.png',
+      },
+    ]);
+  });
+
+  it('rejects symlink attempts that escape the allowed directory', () => {
+    const workspaceDir = makeTempDir(process.cwd(), '.ejclaw-attachment-');
+    const targetPath = writeFile(
+      workspaceDir,
+      'secret-shot.png',
+      ONE_PIXEL_PNG,
+    );
+    const tmpDir = makeTempDir(os.tmpdir(), 'ejclaw-attachment-');
+    const linkPath = path.join(tmpDir, 'linked-shot.png');
+    fs.symlinkSync(targetPath, linkPath);
+
+    const result = validateOutboundAttachments([{ path: linkPath }]);
+
+    expect(result.files).toEqual([]);
+    expect(result.rejected).toEqual([
+      { path: linkPath, reason: 'outside-allowed-dirs' },
+    ]);
+  });
+
+  it('rejects SVG attachments before inspecting file content', () => {
+    const dir = makeTempDir(os.tmpdir(), 'ejclaw-attachment-');
+    const svgPath = writeFile(dir, 'vector.svg', '<svg></svg>');
+
+    const result = validateOutboundAttachments([{ path: svgPath }]);
+
+    expect(result.files).toEqual([]);
+    expect(result.rejected).toEqual([
+      { path: svgPath, reason: 'unsupported-extension' },
+    ]);
+  });
+
+  it('rejects files whose extension and image signature do not match policy', () => {
+    const dir = makeTempDir(os.tmpdir(), 'ejclaw-attachment-');
+    const fakePng = writeFile(dir, 'fake.png', 'not an image');
+    const realPng = writeFile(dir, 'real.png', ONE_PIXEL_PNG);
+
+    expect(validateOutboundAttachments([{ path: fakePng }])).toEqual({
+      files: [],
+      rejected: [{ path: fakePng, reason: 'invalid-image-signature' }],
+    });
+    expect(
+      validateOutboundAttachments([{ path: realPng, mime: 'image/jpeg' }]),
+    ).toEqual({
+      files: [],
+      rejected: [{ path: realPng, reason: 'mime-mismatch' }],
+    });
+  });
+
+  it('rejects non-files and files over the size cap', () => {
+    const dir = makeTempDir(os.tmpdir(), 'ejclaw-attachment-');
+    const nestedDir = path.join(dir, 'nested.png');
+    fs.mkdirSync(nestedDir);
+    const largePng = writeFile(
+      dir,
+      'large.png',
+      Buffer.concat([ONE_PIXEL_PNG, Buffer.alloc(8 * 1024 * 1024)]),
+    );
+
+    expect(validateOutboundAttachments([{ path: nestedDir }])).toEqual({
+      files: [],
+      rejected: [{ path: nestedDir, reason: 'not-file' }],
+    });
+    expect(validateOutboundAttachments([{ path: largePng }])).toEqual({
+      files: [],
+      rejected: [{ path: largePng, reason: 'too-large' }],
+    });
+  });
+});