fix(esl-utils): simplified flat array utility

Deprecation: use `Array.prototype.flat` instead of `flat` utility
exadel-inc · Apr 28, 2023 · 788a782 · 788a782
1 parent 45f282f
commit 788a782
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/src/modules/esl-utils/misc/array.ts b/src/modules/esl-utils/misc/array.ts
@@ -10,9 +10,11 @@ export const tuple = <T>(arr: T[]): Tuple<T>[] => arr.reduce((acc: Tuple<T>[], e
   return acc;
 }, []);
 
-/** Flat array - unwraps one level of nested arrays */
-export const flat = <T>(arr: (null | T | T[])[]): T[] =>
-  arr.reduce((acc: T[], el) => el ? acc.concat(el) : acc, []) as T[];
+/**
+ * Flat array - unwraps one level of nested arrays
+ * @deprecated use `Array.prototype.flat` instead
+ */
+export const flat = <T>(arr: (null | T | T[])[]): T[] => arr.flat(1) as T[];
 
 /** Wraps passed object or primitive to array */
 export const wrap = <T>(arr: undefined | null | T | T[]): T[] => {

diff --git a/src/modules/esl-utils/misc/test/array.test.ts b/src/modules/esl-utils/misc/test/array.test.ts
@@ -13,12 +13,13 @@ describe('misc/array helper tests', () => {
 
   test('flat', () => {
     expect(flat([])).toEqual([]);
+    expect(flat([0])).toEqual([0]);
     expect(flat([1])).toEqual([1]);
     expect(flat([1, 2])).toEqual([1, 2]);
     expect(flat([1, [2, 3]])).toEqual([1, 2, 3]);
     expect(flat([[1, 2], [3, 4]])).toEqual([1, 2, 3, 4]);
     expect(flat([[1], [2, 3, 4], [], [5]])).toEqual([1, 2, 3, 4, 5]);
-    expect(flat([null, 1, 2, 3, [4, 5], null, [6]])).toEqual([1, 2, 3, 4, 5, 6]);
+    expect(flat([null, 1, 2, 3, [4, 5], null, [6]])).toEqual([null, 1, 2, 3, 4, 5, null, 6]);
   });
 
   test('wrap', () => {
@@ -43,6 +44,7 @@ describe('misc/array helper tests', () => {
 
   test('range', () => {
     expect(range(3)).toEqual([0, 1, 2]);
+    // @ts-ignore
     expect(range(9, (x) => x / 8)).toEqual([...Array(9).keys()].map((x) => x / 8));
   });