1 files changed, 27 insertions, 0 deletions
diff --git a/packages/web/src/types/lang-map.d.ts b/packages/web/src/types/lang-map.d.ts
index e69de29bb..b21d2a005 100644
--- a/packages/web/src/types/lang-map.d.ts
+++ b/packages/web/src/types/lang-map.d.ts
@@ -0,0 +1,27 @@
+declare module "lang-map" {
+  /** Returned by calling `map()` */
+  export interface MapReturn {
+    /** All extensions keyed by language name */
+    extensions: Record<string, string[]>;
+    /** All languages keyed by file-extension */
+    languages: Record<string, string[]>;
+  }
+
+  /**
+   * Calling `map()` gives you the raw lookup tables:
+   *
+   * ```js
+   * const { extensions, languages } = map();
+   * ```
+   */
+  function map(): MapReturn;
+
+  /** Static method: get extensions for a given language */
+  namespace map {
+    function extensions(language: string): string[];
+    /** Static method: get languages for a given extension */
+    function languages(extension: string): string[];
+  }
+
+  export = map;
+}