Move ICharTrie types to ambient file

This will automatically share the type to all files.

Avoid error when generating Jest coverage report.

Author: wimpyprogrammer

package.json

@@ -18,7 +18,8 @@
   },
   "jest": {
     "collectCoverageFrom": [
-      "**/src/**/?*.(js|ts)"
+      "**/src/**/?*.(js|ts)",
+      "!**/src/**/?*.d.ts"
     ],
     "transform": {
       "^.+\\.ts$": "ts-jest"

src/types/iCharTree.d.ts

@@ -0,0 +1,3 @@
+type Char = string;
+interface ICharTrie extends Record<Char, CharNode> {}
+type CharNode = ICharTrie;

src/utils/trie.ts

@@ -1,9 +1,5 @@
 import { keys, map, partition, uniq } from 'lodash';
 
-type Char = string;
-interface ICharTrie extends Record<Char, CharNode> {}
-type CharNode = ICharTrie;
-
 const leafNode: CharNode = {};
 
 /**