Add the docs

MAINTAINERS_GUIDE.md

@@ -0,0 +1,15 @@
+To release, bump the version in `package.json` manually, push the commit to let the CI pipeline check the code.
+
+Then build the latest version of the package:
+
+```bash
+pnpm build
+```
+
+Finally, publish the package to npm:
+
+```bash
+pnpm publish
+```
+
+Then go on GitHub and create a release and write the changelog.

README.md

@@ -192,6 +192,14 @@ function getIndex(fileOrFolder: File | Folder): File | undefined;
 
 Get the index (public API) of a slice or segment. When a segment is a file, it is its own index.
 
+#### `isIndex`
+
+```ts
+export function isIndex(fileOrFolder: File | Folder): boolean;
+```
+
+Determine if a given file or folder is an index file (only files can be indexes, folders are accepted for convenience, but always return false).
+
 #### `isSlice`
 
 > [!NOTE]  
@@ -208,4 +216,30 @@ Determine if this folder is a slice.
 
 Slices are defined as folders that contain at least one segment. Additional segment names can be provided if some slice in project contains only unconventional segments.
 
+#### `isCrossImportPublicApi`
+
+```ts
+export function isCrossImportPublicApi(
+  file: File,
+  {
+    inSlice,
+    forSlice,
+    layerPath,
+  }: { inSlice: string; forSlice: string; layerPath: string },
+): boolean;
+```
+
+Check if a given file is a cross-import public API defined in the slice `inSlice` for the slice `forSlice` on a given layer.
+
+For example:
+
+```ts
+const file = { path: "./src/entities/user/@x/product.ts", type: "file" };
+isCrossImportPublicApi(file, {
+  inSlice: "user",
+  forSlice: "product",
+  layerPath: "./src/entities",
+}); // true
+```
+
 [feature-sliced-design]: https://feature-sliced.design

src/fsd-aware-traverse.ts

@@ -163,7 +163,7 @@ export function getIndex(fileOrFolder: File | Folder): File | undefined {
   }
 }
 
-/** Check if a given file or folder is an index file. */
+/** Determine if a given file or folder is an index file. */
 export function isIndex(fileOrFolder: File | Folder): boolean {
   return (
     fileOrFolder.type === "file" && parse(fileOrFolder.path).name === "index"