feat(desktop): add individual datasource tools

src/desktop/cachePath.test.ts

@@ -0,0 +1,265 @@
+import {
+  closeSync,
+  constants,
+  fstatSync,
+  mkdirSync,
+  mkdtempSync,
+  openSync,
+  readFileSync,
+  realpathSync,
+  rmSync,
+  type Stats,
+  statSync,
+  symlinkSync,
+  writeFileSync,
+} from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+
+import {
+  type ContainedCacheReadOperations,
+  getCacheDir,
+  readContainedCacheTextFile,
+} from './cachePath.js';
+
+describe('readContainedCacheTextFile', () => {
+  const temporaryPaths: string[] = [];
+
+  afterEach(() => {
+    for (const path of temporaryPaths.splice(0)) {
+      rmSync(path, { recursive: true, force: true });
+    }
+  });
+
+  function cacheDirectory(label: string): string {
+    const directory = mkdtempSync(join(getCacheDir(), `contained-cache-${label}-`));
+    temporaryPaths.push(directory);
+    return directory;
+  }
+
+  function outsideDirectory(label: string): string {
+    const directory = mkdtempSync(join(tmpdir(), `contained-cache-outside-${label}-`));
+    temporaryPaths.push(directory);
+    return directory;
+  }
+
+  function defaultOperations(
+    overrides: Partial<ContainedCacheReadOperations> = {},
+  ): ContainedCacheReadOperations {
+    return {
+      open: (path: string, flags: number) => openSync(path, flags),
+      fstat: (fd: number) => fstatSync(fd),
+      realpath: (path: string) => realpathSync(path),
+      stat: (path: string) => statSync(path),
+      read: (fd: number) => readFileSync(fd),
+      close: (fd: number) => closeSync(fd),
+      ...overrides,
+    } satisfies ContainedCacheReadOperations;
+  }
+
+  it('rejects lexical sibling and traversal paths before opening them', () => {
+    const open = vi.fn(() => {
+      throw new Error('must not open');
+    });
+    const operations = defaultOperations({ open });
+    const cacheDir = getCacheDir();
+
+    expect(readContainedCacheTextFile(`${cacheDir}-evil/file.xml`, operations)).toMatchObject({
+      ok: false,
+      issue: 'outside-cache',
+    });
+    expect(
+      readContainedCacheTextFile(join(cacheDir, '..', 'escaped-datasource.xml'), operations),
+    ).toMatchObject({ ok: false, issue: 'outside-cache' });
+    expect(open).not.toHaveBeenCalled();
+  });
+
+  it('reads regular datasource and sidecar files inside the real cache root', () => {
+    const directory = cacheDirectory('valid');
+    const datasourceFile = join(directory, 'datasource.xml');
+    const sidecarFile = `${datasourceFile}.meta.json`;
+    writeFileSync(datasourceFile, '<datasource name="sales"/>');
+    writeFileSync(sidecarFile, '{"instanceId":"safe"}');
+
+    expect(readContainedCacheTextFile(datasourceFile)).toEqual({
+      ok: true,
+      path: datasourceFile,
+      text: '<datasource name="sales"/>',
+    });
+    expect(readContainedCacheTextFile(sidecarFile)).toEqual({
+      ok: true,
+      path: sidecarFile,
+      text: '{"instanceId":"safe"}',
+    });
+  });
+
+  it('opens read-only with no-follow semantics when the platform exposes them', () => {
+    const directory = cacheDirectory('open-flags');
+    const file = join(directory, 'datasource.xml');
+    writeFileSync(file, '<datasource/>');
+    const open = vi.fn((path: string, flags: number) => openSync(path, flags));
+
+    expect(readContainedCacheTextFile(file, defaultOperations({ open })).ok).toBe(true);
+    const flags = open.mock.calls[0]?.[1] ?? 0;
+    const noFollow = typeof constants.O_NOFOLLOW === 'number' ? constants.O_NOFOLLOW : 0;
+    expect(flags).toBe(constants.O_RDONLY | noFollow);
+  });
+
+  it('rejects a final-component symlink that escapes the cache', () => {
+    const directory = cacheDirectory('final-symlink');
+    const outside = outsideDirectory('final-symlink');
+    const outsideFile = join(outside, 'secret.xml');
+    const candidate = join(directory, 'datasource.xml');
+    writeFileSync(outsideFile, '<outside-secret/>');
+    symlinkSync(outsideFile, candidate);
+
+    expect(readContainedCacheTextFile(candidate)).toMatchObject({
+      ok: false,
+      issue: 'unsafe-file',
+    });
+  });
+
+  it('rejects an intermediate-directory symlink that escapes the cache', () => {
+    const directory = cacheDirectory('intermediate-symlink');
+    const outside = outsideDirectory('intermediate-symlink');
+    const outsideFile = join(outside, 'datasource.xml');
+    writeFileSync(outsideFile, '<outside-secret/>');
+    symlinkSync(outside, join(directory, 'linked'));
+
+    expect(readContainedCacheTextFile(join(directory, 'linked', 'datasource.xml'))).toMatchObject({
+      ok: false,
+      issue: 'unsafe-file',
+    });
+  });
+
+  it.each(['final', 'intermediate'] as const)(
+    'rejects a %s sidecar symlink escape without reading external contents',
+    (linkKind) => {
+      const directory = cacheDirectory(`sidecar-${linkKind}`);
+      const outside = outsideDirectory(`sidecar-${linkKind}`);
+      const outsideSidecar = join(outside, 'datasource.xml.meta.json');
+      writeFileSync(outsideSidecar, '{"source_sha256":"external-secret"}');
+      const read = vi.fn((fd: number) => readFileSync(fd));
+      const operations = defaultOperations({ read });
+      let candidate: string;
+      if (linkKind === 'final') {
+        candidate = join(directory, 'datasource.xml.meta.json');
+        symlinkSync(outsideSidecar, candidate);
+      } else {
+        symlinkSync(outside, join(directory, 'linked'));
+        candidate = join(directory, 'linked', 'datasource.xml.meta.json');
+      }
+
+      expect(readContainedCacheTextFile(candidate, operations)).toMatchObject({
+        ok: false,
+        issue: 'unsafe-file',
+      });
+      expect(read).not.toHaveBeenCalled();
+    },
+  );
+
+  it('rejects an opened/current identity mismatch without reading and closes the descriptor', () => {
+    const directory = cacheDirectory('identity-mismatch');
+    const file = join(directory, 'datasource.xml');
+    writeFileSync(file, '<datasource/>');
+    const read = vi.fn((fd: number) => readFileSync(fd));
+    const close = vi.fn((fd: number) => closeSync(fd));
+    const operations = defaultOperations({
+      stat: (path) => withInode(statSync(path), statSync(path).ino + 1),
+      read,
+      close,
+    });
+
+    expect(readContainedCacheTextFile(file, operations)).toMatchObject({
+      ok: false,
+      issue: 'unsafe-file',
+    });
+    expect(read).not.toHaveBeenCalled();
+    expect(close).toHaveBeenCalledTimes(1);
+  });
+
+  it('rejects a candidate whose real path changes across the current-file stat', () => {
+    const directory = cacheDirectory('realpath-change');
+    const file = join(directory, 'datasource.xml');
+    const replacement = join(directory, 'replacement.xml');
+    writeFileSync(file, '<datasource/>');
+    writeFileSync(replacement, '<datasource replacement="true"/>');
+    const read = vi.fn((fd: number) => readFileSync(fd));
+    const close = vi.fn((fd: number) => closeSync(fd));
+    let candidateRealpathCalls = 0;
+    const operations = defaultOperations({
+      realpath: (path) => {
+        if (path === getCacheDir()) return realpathSync(path);
+        candidateRealpathCalls += 1;
+        return candidateRealpathCalls === 1 ? realpathSync(file) : realpathSync(replacement);
+      },
+      read,
+      close,
+    });
+
+    expect(readContainedCacheTextFile(file, operations)).toMatchObject({
+      ok: false,
+      issue: 'unsafe-file',
+    });
+    expect(read).not.toHaveBeenCalled();
+    expect(close).toHaveBeenCalledTimes(1);
+  });
+
+  it('closes the descriptor after both a successful read and a read failure', () => {
+    const directory = cacheDirectory('close');
+    const file = join(directory, 'datasource.xml');
+    writeFileSync(file, '<datasource/>');
+    const closeAfterSuccess = vi.fn((fd: number) => closeSync(fd));
+
+    expect(
+      readContainedCacheTextFile(file, defaultOperations({ close: closeAfterSuccess })).ok,
+    ).toBe(true);
+    expect(closeAfterSuccess).toHaveBeenCalledTimes(1);
+
+    const closeAfterFailure = vi.fn((fd: number) => closeSync(fd));
+    const failure = readContainedCacheTextFile(
+      file,
+      defaultOperations({
+        read: () => {
+          throw new Error('read failed');
+        },
+        close: closeAfterFailure,
+      }),
+    );
+    expect(failure).toMatchObject({ ok: false, issue: 'read-error' });
+    expect(closeAfterFailure).toHaveBeenCalledTimes(1);
+  });
+
+  it('classifies a missing file separately from unreadable and unsafe files', () => {
+    const directory = cacheDirectory('classify');
+    const missing = join(directory, 'missing.xml');
+    const unreadable = join(directory, 'unreadable.xml');
+    const nonFile = join(directory, 'directory.xml');
+    writeFileSync(unreadable, '<datasource/>');
+    mkdirSync(nonFile);
+
+    expect(readContainedCacheTextFile(missing)).toMatchObject({ ok: false, issue: 'missing' });
+    expect(
+      readContainedCacheTextFile(
+        unreadable,
+        defaultOperations({
+          open: () => {
+            const error = new Error('permission denied') as NodeJS.ErrnoException;
+            error.code = 'EACCES';
+            throw error;
+          },
+        }),
+      ),
+    ).toMatchObject({ ok: false, issue: 'read-error' });
+    expect(readContainedCacheTextFile(nonFile)).toMatchObject({
+      ok: false,
+      issue: 'unsafe-file',
+    });
+  });
+});
+
+function withInode(stats: Stats, ino: number): Stats {
+  const copy = Object.assign(Object.create(Object.getPrototypeOf(stats)), stats) as Stats;
+  Object.defineProperty(copy, 'ino', { value: ino, configurable: true });
+  return copy;
+}