Do not keep a singletin of EMPTY_LIST

jdeniau · jdeniau · commit 14631a62274c · 2024-10-18T00:38:00.000+02:00
diff --git a/__tests__/List.ts b/__tests__/List.ts
@@ -829,7 +829,7 @@ describe('List', () => {
   it('chained mutations does not result in new empty list instance', () => {
     const v1 = List(['x']);
     const v2 = v1.withMutations(v => v.push('y').pop().pop());
-    expect(v2).toBe(List());
+    expect(v2).toEqual(List());
   });
 
   it('calling `clear` and `setSize` should set all items to undefined', () => {
@@ -952,11 +952,7 @@ describe('List', () => {
   });
 
   it('Mutating empty list with a JS API should not mutate new instances', () => {
-    expect(() => {
-      Object.assign(List(), List([1, 2]));
-    }).toThrow(
-      "Cannot assign to read only property 'size' of object '[object Object]'"
-    );
+    Object.assign(List(), List([1, 2]));
 
     expect(List().size).toBe(0);
     expect(List().toArray()).toEqual([]);
diff --git a/src/List.js b/src/List.js
@@ -408,13 +408,8 @@ function makeList(origin, capacity, level, root, tail, ownerID, hash) {
   return list;
 }
 
-let EMPTY_LIST;
 export function emptyList() {
-  if (!EMPTY_LIST) {
-    EMPTY_LIST = makeList(0, 0, SHIFT);
-    Object.freeze(EMPTY_LIST);
-  }
-  return EMPTY_LIST;
+  return makeList(0, 0, SHIFT);
 }
 
 function updateList(list, index, value) {

Original file line number	Diff line number	Diff line change
`@@ -408,13 +408,8 @@ function makeList(origin, capacity, level, root, tail, ownerID, hash) {`
`408`	`408`	`return list;`
`409`	`409`	`}`
`410`	`410`
`411`		`-let EMPTY_LIST;`
`412`	`411`	`export function emptyList() {`
`413`		`- if (!EMPTY_LIST) {`
`414`		`- EMPTY_LIST = makeL 6051 ist(0, 0, SHIFT);`
`415`		`- Object.freeze(EMPTY_LIST);`
`416`		`- }`
`417`		`- return EMPTY_LIST;`
	`412`	`+ return makeList(0, 0, SHIFT);`
`418`	`413`	`}`
`419`	`414`
`420`	`415`	`function updateList(list, index, value) {`