Ensure array sequence methods don't error for falsey values.

lodash.js

@@ -15394,18 +15394,26 @@
       };
     });
 
-    // Add `Array` and `String` methods to `lodash.prototype`.
+    // Add `Array` methods to `lodash.prototype`.
     arrayEach(['pop', 'push', 'shift', 'sort', 'splice', 'unshift'], function(methodName) {
       var func = arrayProto[methodName],
           chainName = /^(?:push|sort|unshift)$/.test(methodName) ? 'tap' : 'thru',
+          mutates = methodName != 'sort',
           retUnwrapped = /^(?:pop|shift)$/.test(methodName);
 
       lodash.prototype[methodName] = function() {
         var args = arguments;
         if (retUnwrapped && !this.__chain__) {
-          return func.apply(this.value(), args);
+          var value = this.value();
+          if ((mutates ? !isArray(value) : (value == null))) {
+            value = [];
+          }
+          return func.apply(value, args);
         }
         return this[chainName](function(value) {
+          if ((mutates ? !isArray(value) : (value == null))) {
+            value = [];
+          }
           return func.apply(value, args);
         });
       };

test/test.js

@@ -24331,6 +24331,21 @@
         skipAssert(assert, 5);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).pop() : _().pop();
+          return result === undefined;
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -24353,6 +24368,21 @@
         skipAssert(assert, 2);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).push(1).value() : _().push(1).value();
+          return lodashStable.eq(result, value);
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -24379,6 +24409,21 @@
         skipAssert(assert, 5);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).shift() : _().shift();
+          return result === undefined;
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -24401,6 +24446,21 @@
         skipAssert(assert, 2);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).sort().value() : _().sort().value();
+          return lodashStable.eq(result, value);
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -24427,6 +24487,21 @@
         skipAssert(assert, 5);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).splice(0, 1).value() : _().splice(0, 1).value();
+          return lodashStable.isEqual(result, []);
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -24449,6 +24524,21 @@
         skipAssert(assert, 2);
       }
     });
+
+    QUnit.test('should accept falsey arguments', function(assert) {
+      assert.expect(1);
+
+      var expected = lodashStable.map(falsey, alwaysTrue);
+
+      var actual = lodashStable.map(falsey, function(value, index) {
+        try {
+          var result = index ? _(value).unshift(1).value() : _().unshift(1).value();
+          return lodashStable.eq(result, value);
+        } catch (e) {}
+      });
+
+      assert.deepEqual(actual, expected);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/