From 81644550883aee7ba59feade78fa32dfbf7f9984 Mon Sep 17 00:00:00 2001
From: Javier Julio <JJfutbol@gmail.com>
Date: Tue, 24 Oct 2023 17:31:29 -0400
Subject: [PATCH] Include empty attributes in HTML output (#543)

This is mostly a full revert of commit 1526789 which was a bad change. Empty attributes are valid HTML and should be supported in Arbre (e.g. boolean attributes). The bad commit was for just addressing the class attribute but that applied to any attribute in HTML when it shouldn't have, even for class. Note that if an attribute value is nil then it is removed. This follows similar output logic to Rails `tag.attributes` helper.
---
 lib/arbre/html/attributes.rb                | 11 +----------
 spec/arbre/unit/html/tag_attributes_spec.rb | 14 +++++++-------
 2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/lib/arbre/html/attributes.rb b/lib/arbre/html/attributes.rb
index 8fd92bf6..b0030495 100644
--- a/lib/arbre/html/attributes.rb
+++ b/lib/arbre/html/attributes.rb
@@ -5,16 +5,11 @@ module HTML
     class Attributes < Hash
 
       def to_s
-        flatten_hash.map do |name, value|
-          next if value_empty?(value)
+        flatten_hash.compact.map do |name, value|
           "#{html_escape(name)}=\"#{html_escape(value)}\""
         end.compact.join ' '
       end
 
-      def any?
-        super{ |k,v| !value_empty?(v) }
-      end
-
       protected
 
       def flatten_hash(hash = self, old_path = [], accumulator = {})
@@ -29,10 +24,6 @@ def flatten_hash(hash = self, old_path = [], accumulator = {})
         accumulator
       end
 
-      def value_empty?(value)
-        value.respond_to?(:empty?) ? value.empty? : !value
-      end
-
       def html_escape(s)
         ERB::Util.html_escape(s)
       end
diff --git a/spec/arbre/unit/html/tag_attributes_spec.rb b/spec/arbre/unit/html/tag_attributes_spec.rb
index 19bb80a4..46167579 100644
--- a/spec/arbre/unit/html/tag_attributes_spec.rb
+++ b/spec/arbre/unit/html/tag_attributes_spec.rb
@@ -18,12 +18,12 @@
         expect(tag.to_s).to eq "<tag id=\"my_id\"></tag>\n"
       end
 
-      it "shouldn't render attributes that are empty" do
+      it "should still render attributes that are empty but not nil" do
         tag.class_list # initializes an empty ClassList
         tag.set_attribute :foo, ''
         tag.set_attribute :bar, nil
 
-        expect(tag.to_s).to eq "<tag id=\"my_id\"></tag>\n"
+        expect(tag.to_s).to eq "<tag id=\"my_id\" class=\"\" foo=\"\"></tag>\n"
       end
 
       context "with hyphenated attributes" do
@@ -41,17 +41,17 @@
           expect(tag.to_s).to eq "<tag id=\"my_id\" data-action=\"some_action\"></tag>\n"
         end
 
-        it "shouldn't render attributes that are empty" do
+        it "should still render attributes that are empty but not nil" do
           tag.class_list # initializes an empty ClassList
           tag.set_attribute :foo, { bar: '' }
           tag.set_attribute :bar, { baz: nil }
 
-          expect(tag.to_s).to eq "<tag id=\"my_id\" data-action=\"some_action\"></tag>\n"
+          expect(tag.to_s).to eq "<tag id=\"my_id\" data-action=\"some_action\" class=\"\" foo-bar=\"\"></tag>\n"
         end
       end
 
       context "when there is a deeply nested attribute" do
-        before { tag.build id: "my_id", foo: { bar: { baz: 'foozle' } } }
+        before { tag.build id: "my_id", foo: { bar: { bat: nil, baz: 'foozle' } } }
 
         it "should flatten the attributes when rendering to html" do
           expect(tag.to_s).to eq "<tag id=\"my_id\" foo-bar-baz=\"foozle\"></tag>\n"
@@ -59,10 +59,10 @@
       end
 
       context "when there are multiple nested attributes" do
-        before { tag.build id: "my_id", foo: { bar: 'foozle1', baz: 'foozle2' } }
+        before { tag.build id: "my_id", foo: { bar: 'foozle1', bat: nil, baz: '' } }
 
         it "should flatten the attributes when rendering to html" do
-          expect(tag.to_s).to eq "<tag id=\"my_id\" foo-bar=\"foozle1\" foo-baz=\"foozle2\"></tag>\n"
+          expect(tag.to_s).to eq "<tag id=\"my_id\" foo-bar=\"foozle1\" foo-baz=\"\"></tag>\n"
         end
       end
     end