From a17a11722bdb3fbb7bb0e0159b8fc6835250bff3 Mon Sep 17 00:00:00 2001
From: Pablo Villoslada Puigcerber <pablo85@gmail.com>
Date: Sat, 6 Dec 2014 18:29:31 +0100
Subject: [PATCH] fix(filter): throw error if not used with an array

Throw error if filter is not used with an array.

Closes #9992

BREAKING CHANGE: Previously, the filter was not applied if used with a non array.
Now, it throws an error.
---
 docs/content/error/filter/notarray.ngdoc |  8 ++++++
 src/ng/filter/filter.js                  |  8 +++++-
 test/ng/filter/filterSpec.js             | 31 +++++++++++++++++++++++-
 test/ngScenario/dslSpec.js               |  2 +-
 4 files changed, 46 insertions(+), 3 deletions(-)
 create mode 100644 docs/content/error/filter/notarray.ngdoc

diff --git a/docs/content/error/filter/notarray.ngdoc b/docs/content/error/filter/notarray.ngdoc
new file mode 100644
index 000000000000..c46befba598c
--- /dev/null
+++ b/docs/content/error/filter/notarray.ngdoc
@@ -0,0 +1,8 @@
+@ngdoc error
+@name filter:notarray
+@fullName Not an array
+@description
+
+This error occurs when {@link ng.filter filter} is not used with an array.
+Filter must be used with an array so a subset of items can be returned.
+The array can be initialized asynchronously so null or undefined won't throw this error.
diff --git a/src/ng/filter/filter.js b/src/ng/filter/filter.js
index a739a1ca21c7..8b95b7a04f7f 100644
--- a/src/ng/filter/filter.js
+++ b/src/ng/filter/filter.js
@@ -117,7 +117,13 @@
  */
 function filterFilter() {
   return function(array, expression, comparator) {
-    if (!isArray(array)) return array;
+    if (!isArray(array)) {
+      if (array == null) {
+        return array;
+      } else {
+        throw minErr('filter')('notarray', 'Expected array but received: {0}', array);
+      }
+    }
 
     var predicateFn;
     var matchAgainstAnyProp;
diff --git a/test/ng/filter/filterSpec.js b/test/ng/filter/filterSpec.js
index 7e14f5f567f4..3c07d2496aed 100644
--- a/test/ng/filter/filterSpec.js
+++ b/test/ng/filter/filterSpec.js
@@ -195,7 +195,7 @@ describe('Filter: filter', function() {
     expect(filter(items, expr, true).length).toBe(1);
     expect(filter(items, expr, true)[0]).toBe(items[0]);
 
-    // Inherited function proprties
+    // Inherited function properties
     function Item(text) {
         this.text = text;
     }
@@ -323,6 +323,35 @@ describe('Filter: filter', function() {
   });
 
 
+  it('should throw an error when is not used with an array', function() {
+    var item = {'not': 'array'};
+    expect(function() { filter(item, {}); }).
+      toThrowMinErr('filter', 'notarray', 'Expected array but received: {"not":"array"}');
+
+    item = Object.create(null);
+    expect(function() { filter(item, {}); }).
+      toThrowMinErr('filter', 'notarray', 'Expected array but received: {}');
+
+    item = {
+      toString: null,
+      valueOf: null
+    };
+    expect(function() { filter(item, {}); }).
+      toThrowMinErr('filter', 'notarray', 'Expected array but received: {"toString":null,"valueOf":null}');
+  });
+
+
+  it('should return undefined when the array is undefined', function() {
+    expect(filter(undefined, {})).toBeUndefined();
+  });
+
+
+  it('should return null when the value of the array is null', function() {
+    var item = null;
+    expect(filter(item, {})).toBe(null);
+  });
+
+
   describe('should support comparator', function() {
 
     it('not consider `object === "[object Object]"` in non-strict comparison', function() {
diff --git a/test/ngScenario/dslSpec.js b/test/ngScenario/dslSpec.js
index 2287b6bf3071..5db5801ca551 100644
--- a/test/ngScenario/dslSpec.js
+++ b/test/ngScenario/dslSpec.js
@@ -624,7 +624,7 @@ describe("angular.scenario.dsl", function() {
       });
 
       it('should match bindings by substring match', function() {
-        compile('<pre ng-bind="foo.bar | filter"></pre>', 'binding value');
+        compile('<pre ng-bind="foo.bar | lowercase"></pre>', 'binding value');
         $root.dsl.binding('foo . bar');
         expect($root.futureResult).toEqual('binding value');
       });