Handle TypeError from `where` filter gracefully (#9292)

Merge pull request 9292

lib/jekyll/filters.rb

@@ -441,6 +441,14 @@ module Jekyll
       property.split(".").reduce(liquid_data) do |data, key|
         data.respond_to?(:[]) && data[key]
       end
+    rescue TypeError => e
+      msg = if liquid_data.is_a?(Array)
+              "Error accessing object (#{liquid_data.to_s[0...20]}) with given key. Expected an " \
+                "integer but got #{property.inspect} instead."
+            else
+              e.message
+            end
+      raise e, msg
     end
 
     FLOAT_LIKE   = %r!\A\s*-?(?:\d+\.?\d*|\.\d+)\s*\Z!.freeze

test/test_filters.rb

@@ -958,6 +958,18 @@ class TestFilters < JekyllUnitTest
         results = @filter.where(SelectDummy.new, "obj", "1 == 1")
         assert_equal [], results
       end
+
+      should "gracefully handle invalid property type" do
+        hash = {
+          "members" => { "name" => %w(John Jane Jimmy) },
+          "roles"   => %w(Admin Recruiter Manager),
+        }
+        err = assert_raises(TypeError) { @filter.where(hash, "name", "Jimmy") }
+        truncatd_arr_str = hash["roles"].to_liquid.to_s[0...20]
+        msg = "Error accessing object (#{truncatd_arr_str}) with given key. Expected an integer " \
+              'but got "name" instead.'
+        assert_equal msg, err.message
+      end
     end
 
     context "where_exp filter" do