test: trip when the mirrored editor types move upstream

package.json

@@ -52,6 +52,7 @@
   },
   "devDependencies": {
     "@testing-library/react": "16.3.2",
+    "@types/node": "24.10.9",
     "@types/react": "19.2.17",
     "@types/react-dom": "19.2.3",
     "@vitest/coverage-v8": "4.1.10",

src/types.ts

@@ -18,6 +18,11 @@ export interface ImageEditorSaveResult {
 // KEEP IN SYNC WITH packages/image-editor/src/index.ts in the unlayer
 // monorepo — these mirror the private @unlayer/image-editor package's
 // public API until they move into @unlayer/types.
+//
+// test/typesDrift.test.ts enforces the "until": it fails as soon as
+// @unlayer/types exports any of these names, so the local copy gets deleted
+// rather than left to diverge. It cannot detect the private package
+// changing underneath us — that still needs a human.
 
 /**
  * Options for mounting the image editor.

test/typesDrift.test.ts

@@ -0,0 +1,49 @@
+import { readFileSync, readdirSync } from 'node:fs';
+import { join } from 'node:path';
+
+// src/types.ts hand-mirrors the private @unlayer/image-editor public API,
+// with a comment saying it does so "until they move into @unlayer/types".
+// Nothing enforced the "until": once the move happens, the local copies
+// silently become a second, diverging source of truth — which is how #25
+// (a missing `dock`/`corners`) reached users.
+//
+// This is a tripwire, not a full drift check: a real one needs access to the
+// private package. It fails the moment @unlayer/types starts exporting any
+// mirrored name, so the local copy gets deleted rather than left to rot.
+const MIRRORED = [
+  'MountOptions',
+  'ImageEditorInstance',
+  'ImageEditorEmbed',
+  'ImageEditorSaveResult',
+];
+
+const collectDeclarations = (dir: string): string => {
+  let out = '';
+  for (const entry of readdirSync(dir, { withFileTypes: true })) {
+    const path = join(dir, entry.name);
+    if (entry.isDirectory()) out += collectDeclarations(path);
+    else if (entry.name.endsWith('.d.ts')) out += readFileSync(path, 'utf8');
+  }
+  return out;
+};
+
+it('still needs its local copy of the image editor types', () => {
+  // Read the package directory directly: @unlayer/types restricts its
+  // "exports" field, so require.resolve cannot reach its package.json.
+  const declarations = collectDeclarations(
+    join(process.cwd(), 'node_modules', '@unlayer', 'types')
+  );
+
+  const moved = MIRRORED.filter((name) =>
+    new RegExp(`\\b(interface|type)\\s+${name}\\b`).test(declarations)
+  );
+
+  expect(
+    moved,
+    moved.length
+      ? `@unlayer/types now exports ${moved.join(', ')}. Delete the mirrored ` +
+          `declaration(s) from src/types.ts and re-export from @unlayer/types ` +
+          `instead, then drop the name(s) from this test.`
+      : ''
+  ).toEqual([]);
+});

tsconfig.json

@@ -19,6 +19,6 @@
     "forceConsistentCasingInFileNames": true,
     "noEmit": true,
     "resolveJsonModule": true,
-    "types": ["vitest/globals"]
+    "types": ["vitest/globals", "node"]
   }
 }