Fix regression when using empty/nil properties with array filters (#1944)

* Make all array filters that use `filter_array` util process empty string and nil correctly

* up version

* fix ordering of checks

* also do it for map

* Do not raise property error

* Gracefully empty property in map filter

---------

Co-authored-by: Marco Concetto Rudilosso <[email protected]>

Author: ianks

lib/liquid/standardfilters.rb

@@ -3,7 +3,6 @@
 require 'cgi'
 require 'base64'
 require 'bigdecimal'
-
 module Liquid
   module StandardFilters
     MAX_I32 = (1 << 31) - 1
@@ -538,6 +537,10 @@ def reverse(input)
     # @liquid_return [array[untyped]]
     def map(input, property)
       property = Utils.to_s(property)
+
+      # Return the input array if property is empty (no-op)
+      return InputIterator.new(input, context).to_a if property.empty?
+
       InputIterator.new(input, context).map do |e|
         e = e.call if e.is_a?(Proc)
 
@@ -986,12 +989,11 @@ def sum(input, property = nil)
     attr_reader :context
 
     def filter_array(input, property, target_value, default_value = [], &block)
-      property = Liquid::Utils.to_s(property)
-      return default_value if property.empty?
-
       ary = InputIterator.new(input, context)
       return default_value if ary.empty?
 
+      property = Utils.to_s(property)
+
       block.call(ary) do |item|
         if target_value.nil?
           item[property]

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.8.2"
+  VERSION = "5.8.3"
 end

test/integration/standard_filter_test.rb

@@ -560,15 +560,47 @@ def test_map_returns_empty_on_2d_input_array
     end
   end
 
-  def test_map_returns_empty_with_no_property
-    foo = [
+  def test_map_with_nil_property
+    array = [
+      { "handle" => "alpha", "value" => "A" },
+      { "handle" => "beta", "value" => "B" },
+      { "handle" => "gamma", "value" => "C" }
+    ]
+
+    assert_template_result("alpha beta gamma", "{{ array | map: nil | map: 'handle' | join: ' ' }}", { "array" => array })
+  end
+
+  def test_map_with_empty_string_property
+    array = [
+      { "handle" => "alpha", "value" => "A" },
+      { "handle" => "beta", "value" => "B" },
+      { "handle" => "gamma", "value" => "C" }
+    ]
+
+    assert_template_result("alpha beta gamma", "{{ array | map: '' | map: 'handle' | join: ' ' }}", { "array" => array })
+  end
+
+  def test_map_with_value_property
+    array = [
+      { "handle" => "alpha", "value" => "A" },
+      { "handle" => "beta", "value" => "B" },
+      { "handle" => "gamma", "value" => "C" }
+    ]
+
+    assert_template_result("A B C", "{{ array | map: 'value' | join: ' ' }}", { "array" => array })
+  end
+
+  def test_map_returns_input_with_no_property
+    input = [
       [1],
       [2],
       [3],
     ]
-    assert_raises(Liquid::ArgumentError) do
-      @filters.map(foo, nil)
-    end
+    result = @filters.map(input, nil)
+    assert_equal(input.flatten, result)
+
+    result = @filters.map(input, '')
+    assert_equal(input.flatten, result)
   end
 
   def test_sort_works_on_enumerables
@@ -1033,6 +1065,22 @@ def test_where
     assert_template_result(expected_output, template, { "array" => array })
   end
 
+  def test_where_with_empty_string_is_a_no_op
+    environment = { "array" => ["alpha", "beta", "gamma"] }
+    expected_output = "alpha beta gamma"
+    template = "{{ array | where: '' | join: ' ' }}"
+
+    assert_template_result(expected_output, template, environment)
+  end
+
+  def test_where_with_nil_is_a_no_op
+    environment = { "array" => ["alpha", "beta", "gamma"] }
+    expected_output = "alpha beta gamma"
+    template = "{{ array | where: nil | join: ' ' }}"
+
+    assert_template_result(expected_output, template, environment)
+  end
+
   def test_where_with_value
     array = [
       { "handle" => "alpha", "ok" => true },