feat(limitTo): add support for array-likes

- Add support for array-like objects

Author: wesleycho

src/ng/filter/limitTo.js

@@ -108,19 +108,25 @@ function limitToFilter() {
     if (isNaN(limit)) return input;
 
     if (isNumber(input)) input = input.toString();
-    if (!isArray(input) && !isString(input)) return input;
+    if (!isArrayLike(input)) return input;
 
     begin = (!begin || isNaN(begin)) ? 0 : toInt(begin);
     begin = (begin < 0) ? Math.max(0, input.length + begin) : begin;
 
     if (limit >= 0) {
-      return input.slice(begin, begin + limit);
+      return sliceFn(input, begin, begin + limit);
     } else {
       if (begin === 0) {
-        return input.slice(limit, input.length);
+        return sliceFn(input, limit, input.length);
       } else {
-        return input.slice(Math.max(0, begin + limit), begin);
+        return sliceFn(input, Math.max(0, begin + limit), begin);
       }
     }
   };
 }
+
+function sliceFn(input, idx, length) {
+  if (isString(input)) return input.slice(idx, length);
+
+  return Array.prototype.slice.call(input, idx, length);
+}

test/ng/filter/limitToSpec.js

@@ -4,15 +4,35 @@ describe('Filter: limitTo', function() {
   var items;
   var str;
   var number;
+  var arrayLike;
   var limitTo;
 
   beforeEach(inject(function($filter) {
     items = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
     str = "tuvwxyz";
     number = 100.045;
+    arrayLike = {
+      0: 'a',
+      1: 'b',
+      2: 'c',
+      3: 'd',
+      4: 'e',
+      5: 'f',
+      6: 'g',
+      7: 'h',
+      get length() {
+        return Object.keys(this).length - 1;
+      }
+    };
     limitTo = $filter('limitTo');
   }));
 
+  function isInObject(obj) {
+    return function(key) {
+      return !!obj[key];
+    };
+  }
+
 
   it('should return the first X items when X is positive', function() {
     expect(limitTo(items, 3)).toEqual(['a', 'b', 'c']);
@@ -21,20 +41,26 @@ describe('Filter: limitTo', function() {
     expect(limitTo(str, '3')).toEqual("tuv");
     expect(limitTo(number, 3)).toEqual("100");
     expect(limitTo(number, '3')).toEqual("100");
+    expect(limitTo(arrayLike, 3)).toEqual(['a', 'b', 'c']);
+    expect(limitTo(arrayLike, '3')).toEqual(['a', 'b', 'c']);
   });
 
   it('should return the first X items beginning from index Y when X and Y are positive', function() {
     expect(limitTo(items, 3, '3')).toEqual(['d', 'e', 'f']);
     expect(limitTo(items, '3', 3)).toEqual(['d', 'e', 'f']);
     expect(limitTo(str, 3, 3)).toEqual("wxy");
     expect(limitTo(str, '3', '3')).toEqual("wxy");
+    expect(limitTo(arrayLike, 3, 3)).toEqual(['d', 'e', 'f']);
+    expect(limitTo(arrayLike, '3', '3')).toEqual(['d', 'e', 'f']);
   });
 
   it('should return the first X items beginning from index Y when X is positive and Y is negative', function() {
     expect(limitTo(items, 3, '-3')).toEqual(['f', 'g', 'h']);
     expect(limitTo(items, '3', -3)).toEqual(['f', 'g', 'h']);
     expect(limitTo(str, 3, -3)).toEqual("xyz");
     expect(limitTo(str, '3', '-3')).toEqual("xyz");
+    expect(limitTo(arrayLike, 3, '-3')).toEqual(['f', 'g', 'h']);
+    expect(limitTo(arrayLike, '3', -3)).toEqual(['f', 'g', 'h']);
   });
 
   it('should return the last X items when X is negative', function() {
@@ -44,25 +70,33 @@ describe('Filter: limitTo', function() {
     expect(limitTo(str, '-3')).toEqual("xyz");
     expect(limitTo(number, -3)).toEqual("045");
     expect(limitTo(number, '-3')).toEqual("045");
+    expect(limitTo(arrayLike, -3)).toEqual(['f', 'g', 'h']);
+    expect(limitTo(arrayLike, '-3')).toEqual(['f', 'g', 'h']);
   });
 
   it('should return the last X items until index Y when X and Y are negative', function() {
     expect(limitTo(items, -3, '-3')).toEqual(['c', 'd', 'e']);
     expect(limitTo(items, '-3', -3)).toEqual(['c', 'd', 'e']);
     expect(limitTo(str, -3, -3)).toEqual("uvw");
     expect(limitTo(str, '-3', '-3')).toEqual("uvw");
+    expect(limitTo(arrayLike, -3, '-3')).toEqual(['c', 'd', 'e']);
+    expect(limitTo(arrayLike, '-3', -3)).toEqual(['c', 'd', 'e']);
   });
 
   it('should return the last X items until index Y when X is negative and Y is positive', function() {
     expect(limitTo(items, -3, '4')).toEqual(['b', 'c', 'd']);
     expect(limitTo(items, '-3', 4)).toEqual(['b', 'c', 'd']);
     expect(limitTo(str, -3, 4)).toEqual("uvw");
     expect(limitTo(str, '-3', '4')).toEqual("uvw");
+    expect(limitTo(arrayLike, -3, '4')).toEqual(['b', 'c', 'd']);
+    expect(limitTo(arrayLike, '-3', 4)).toEqual(['b', 'c', 'd']);
   });
 
   it('should return an empty array when X = 0', function() {
     expect(limitTo(items, 0)).toEqual([]);
     expect(limitTo(items, '0')).toEqual([]);
+    expect(limitTo(arrayLike, 0)).toEqual([]);
+    expect(limitTo(arrayLike, '0')).toEqual([]);
   });
 
   it('should return entire array when X cannot be parsed', function() {
@@ -71,6 +105,11 @@ describe('Filter: limitTo', function() {
     expect(limitTo(items, 'undefined')).toEqual(items);
     expect(limitTo(items, null)).toEqual(items);
     expect(limitTo(items, undefined)).toEqual(items);
+    expect(limitTo(arrayLike, 'bogus')).toEqual(arrayLike);
+    expect(limitTo(arrayLike, 'null')).toEqual(arrayLike);
+    expect(limitTo(arrayLike, 'undefined')).toEqual(arrayLike);
+    expect(limitTo(arrayLike, null)).toEqual(arrayLike);
+    expect(limitTo(arrayLike, undefined)).toEqual(arrayLike);
   });
 
   it('should return an empty string when X = 0', function() {
@@ -97,12 +136,16 @@ describe('Filter: limitTo', function() {
     expect(limitTo(str, '3', 'undefined')).toEqual(limitTo(str, '3'));
     expect(limitTo(str, '-3', null)).toEqual(limitTo(str, '-3', 0));
     expect(limitTo(str, 3, undefined)).toEqual(limitTo(str, 3));
+    expect(limitTo(arrayLike, 3, 'bogus')).toEqual(limitTo(items, 3, 0));
+    expect(limitTo(arrayLike, -3, 'null')).toEqual(limitTo(items, -3));
+    expect(limitTo(arrayLike, '3', 'undefined')).toEqual(limitTo(items, '3', 0));
+    expect(limitTo(arrayLike, '-3', null)).toEqual(limitTo(items, '-3'));
+    expect(limitTo(arrayLike, 3, undefined)).toEqual(limitTo(items, 3, 0));
   });
 
-  it('should return input if not String or Array or Number', function() {
+  it('should return input if not String or array-like or Number', function() {
     expect(limitTo(null, 1)).toEqual(null);
     expect(limitTo(undefined, 1)).toEqual(undefined);
-    expect(limitTo({}, 1)).toEqual({});
   });
 
 
@@ -111,8 +154,13 @@ describe('Filter: limitTo', function() {
     expect(limitTo(items, '9')).toEqual(items);
     expect(limitTo(items, -9)).toEqual(items);
     expect(limitTo(items, '-9')).toEqual(items);
+    expect(limitTo(arrayLike, 9)).toEqual(items);
+    expect(limitTo(arrayLike, '9')).toEqual(items);
+    expect(limitTo(arrayLike, -9)).toEqual(items);
+    expect(limitTo(arrayLike, '-9')).toEqual(items);
 
-    expect(limitTo(items, 9)).not.toBe(items);
+    expect(limitTo(arrayLike, 9)).not.toBe(items);
+    expect(limitTo(arrayLike, 9)).not.toBe(items);
   });
 
   it('should return the entire string if X exceeds input length', function() {
@@ -129,6 +177,10 @@ describe('Filter: limitTo', function() {
     expect(limitTo(items, 'Infinity')).toEqual(items);
     expect(limitTo(items, -Infinity)).toEqual(items);
     expect(limitTo(items, '-Infinity')).toEqual(items);
+    expect(limitTo(arrayLike, Infinity)).toEqual(items);
+    expect(limitTo(arrayLike, 'Infinity')).toEqual(items);
+    expect(limitTo(arrayLike, -Infinity)).toEqual(items);
+    expect(limitTo(arrayLike, '-Infinity')).toEqual(items);
   });
 
   it('should return the entire string when limited by Infinity', function() {
@@ -141,6 +193,8 @@ describe('Filter: limitTo', function() {
   it('should return an empty array if Y exceeds input length', function() {
     expect(limitTo(items, '3', 12)).toEqual([]);
     expect(limitTo(items, -3, '12')).toEqual([]);
+    expect(limitTo(arrayLike, '3', 12)).toEqual([]);
+    expect(limitTo(arrayLike, -3, '12')).toEqual([]);
   });
 
   it('should return an empty string if Y exceeds input length', function() {
@@ -153,19 +207,25 @@ describe('Filter: limitTo', function() {
     expect(limitTo(items, '-4', -12)).toEqual(['e', 'f', 'g', 'h']);
     expect(limitTo(str, 4, '-12')).toEqual("tuvw");
     expect(limitTo(str, '-4', -12)).toEqual("wxyz");
+    expect(limitTo(arrayLike, 4, '-12')).toEqual(['a', 'b', 'c', 'd']);
+    expect(limitTo(arrayLike, '-4', -12)).toEqual(['e', 'f', 'g', 'h']);
   });
 
   it('should return the entire string beginning from Y if X is positive and X+Y exceeds input length', function() {
     expect(limitTo(items, 7, 3)).toEqual(['d', 'e', 'f', 'g', 'h']);
     expect(limitTo(items, 7, -3)).toEqual(['f', 'g', 'h']);
     expect(limitTo(str, 6, 3)).toEqual("wxyz");
     expect(limitTo(str, 6, -3)).toEqual("xyz");
+    expect(limitTo(arrayLike, 7, 3)).toEqual(['d', 'e', 'f', 'g', 'h']);
+    expect(limitTo(arrayLike, 7, -3)).toEqual(['f', 'g', 'h']);
   });
 
   it('should return the entire string until index Y if X is negative and X+Y exceeds input length', function() {
     expect(limitTo(items, -7, 3)).toEqual(['a', 'b', 'c']);
     expect(limitTo(items, -7, -3)).toEqual(['a', 'b', 'c', 'd', 'e']);
     expect(limitTo(str, -6, 3)).toEqual("tuv");
     expect(limitTo(str, -6, -3)).toEqual("tuvw");
+    expect(limitTo(arrayLike, -7, 3)).toEqual(['a', 'b', 'c']);
+    expect(limitTo(arrayLike, -7, -3)).toEqual(['a', 'b', 'c', 'd', 'e']);
   });
 });