immutable-js
diff --git a/‎__tests__/List.ts
Copy file name to clipboardExpand all lines: __tests__/List.ts
+3-3Lines changed: 3 additions & 3 deletions b/‎__tests__/List.ts
Copy file name to clipboardExpand all lines: __tests__/List.ts
+3-3Lines changed: 3 additions & 3 deletions
diff --git a/‎__tests__/Seq.ts
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+10-2Lines changed: 10 additions & 2 deletions b/‎__tests__/Seq.ts
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+10-2Lines changed: 10 additions & 2 deletions
diff --git a/‎__tests__/Set.ts
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+3-3Lines changed: 3 additions & 3 deletions b/‎__tests__/Set.ts
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+3-3Lines changed: 3 additions & 3 deletions
diff --git a/‎src/utils/isArrayLike.js
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+11-1Lines changed: 11 additions & 1 deletion b/‎src/utils/isArrayLike.js
Copy file name to clipboardExpand all lines: src/utils/isArrayLike.js
+11-1Lines changed: 11 additions & 1 deletion
@@ -58,9 +58,9 @@ describe('List', () => {
   });
 
   it('accepts an array-like', () => {
-    const v = List({ length: 3, 1: 'b' } as any);
-    expect(v.get(1)).toBe('b');
-    expect(v.toArray()).toEqual([undefined, 'b', undefined]);
+    const v = List({ length: 3, 2: 'c' } as any);
+    expect(v.get(2)).toBe('c');
+    expect(v.toArray()).toEqual([undefined, undefined, 'c']);
   });
 
   it('accepts any array-like collection, including strings', () => {
 
@@ -47,11 +47,19 @@ describe('Seq', () => {
   });
 
   it('accepts an array-like', () => {
-    const alike: any = { length: 2, 0: 'a', 1: 'b' };
-    const seq = Seq(alike);
+    const seq = Seq({ length: 2, 0: 'a', 1: 'b' });
     expect(isIndexed(seq)).toBe(true);
     expect(seq.size).toBe(2);
     expect(seq.get(1)).toBe('b');
+
+    const map = Seq({ length: 1, foo: 'bar' });
+    expect(isIndexed(map)).toBe(false);
+    expect(map.size).toBe(2);
+    expect(map.get('foo')).toBe('bar');
+
+    const empty = Seq({ length: 0 });
+    expect(isIndexed(empty)).toBe(true);
+    expect(empty.size).toEqual(0);
   });
 
   it('does not accept a scalar', () => {
 
@@ -20,11 +20,11 @@ describe('Set', () => {
   });
 
   it('accepts array-like of values', () => {
-    const s = Set<any>({ length: 3, 1: 2 } as any);
+    const s = Set<any>({ length: 3, 2: 3 } as any);
     expect(s.size).toBe(2);
     expect(s.has(undefined)).toBe(true);
-    expect(s.has(2)).toBe(true);
-    expect(s.has(1)).toBe(false);
+    expect(s.has(3)).toBe(true);
+    expect(s.has(2)).toBe(false);
   });
 
   it('accepts string, an array-like collection', () => {
 
@@ -6,5 +6,15 @@
  */
 
 export default function isArrayLike(value) {
-  return value && typeof value.length === 'number';
+  if (Array.isArray(value) || typeof value === 'string') {
+    return true;
+  }
+
+  return (
+    value &&
+    typeof value === 'object' &&
+    typeof value.length === 'number' &&
+    ((value.length && value.length - 1 in value) ||
+      (!value.length && Object.keys(value).length <= 1))
+  );
 }