Fix behavior with string unicodes diffs

Author: caub

src/diff/lcs.ts

@@ -1,4 +1,6 @@
-function lcs<T>(a: T[], b: T[], compareFunc: (a: T, b: T) => boolean): number {
+function lcs<T>(_a: T[], _b: T[], compareFunc: (a: T, b: T) => boolean): number {
+  const a = [..._a], // normalize string unicodes
+    b = [..._b];
   const M = a.length,
     N = b.length;
   const MAX = M + N;

src/test/patch.spec.ts

@@ -19,19 +19,19 @@ describe('Get Patch', () => {
         type: 'add',
         oldPos,
         newPos,
-        items: str.split(''),
+        items: [...str],
       };
     }
     function remove(oldPos: number, newPos: number, str: string): es.PatchItem<string> {
       return {
         type: 'remove',
         oldPos,
         newPos,
-        items: str.split(''),
+        items: [...str],
       };
     }
     function es_str(a: string, b: string, script: es.Patch<string>, msg?: string) {
-      assert.deepStrictEqual(es.getPatch(a.split(''), b.split('')), script, msg);
+      assert.deepStrictEqual(es.getPatch([...a], [...b]), script, msg);
     }
 
     es_str('', '', [], 'empty');
@@ -103,5 +103,7 @@ describe('Get Patch', () => {
       [add(12, 12, '12345678901234567890')],
       'remove 12345678901234567890',
     );
+
+    es_str('💢💩💧', '💢💫💧', [remove(1, 1, '💩'), add(2, 1, '💫')], 'works with unicodes')
   });
 });

tsconfig.json

@@ -8,6 +8,7 @@
     "declaration": true,
     "outDir": "./dist",
     "strict": true,
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "downlevelIteration": true
   }
 }