From f0de67f45cf73a7c674c6fc45707362ec4cd549c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Mon, 14 Mar 2022 19:50:53 +0000
Subject: [PATCH 01/15] Add test to make sure `<details>` elements have a
 `<summary>` element

---
 .../accessibility/details_has_summary.rb      | 39 +++++++++++++++++++
 .../accessibility/details_has_summary_test.rb | 23 +++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 lib/erblint-github/linters/github/accessibility/details_has_summary.rb
 create mode 100644 test/linters/accessibility/details_has_summary_test.rb

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
new file mode 100644
index 0000000..9e1bcba
--- /dev/null
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+require_relative "../../custom_helpers"
+
+module ERBLint
+  module Linters
+    module GitHub
+      module Accessibility
+        class DetailsHasSummary < Linter
+          include ERBLint::Linters::CustomHelpers
+          include LinterRegistry
+
+          MESSAGE = "<details> elements need to have explict <summary> elements"
+
+          def run(processed_source)
+            tags(processed_source).each do |tag|
+              next if tag.closing?
+              next unless tag.name == "details"
+
+              # Find the details element index in the AST
+              index = processed_source.ast.to_a.find_index(tag.node)
+
+              # Get the next element in the AST
+              next_node = processed_source.ast.to_a[index + 1]
+              next_tag = BetterHtml::Tree::Tag.from_node(next_node)
+
+              # If the next element is a summary, we're good
+              next if next_tag.name == "summary"
+
+              generate_offense(self.class, processed_source, tag)
+            end
+
+            rule_disabled?(processed_source)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
new file mode 100644
index 0000000..b7c0b1d
--- /dev/null
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class DetailsHasSummary < LinterTestCase
+  def linter_class
+    ERBLint::Linters::GitHub::Accessibility::DetailsHasSummary
+  end
+
+  def test_warns_if_details_doesnt_have_a_summary
+    @file = "<details>I don't have a summary element</details>"
+    @linter.run(processed_source)
+
+    assert_equal @linter.offenses.count, 1
+  end
+
+  def test_does_not_warn_if_only_disabled_attribute_is_set
+    @file = "<details><summary>Expand me!</summary><button>Surprise button!</button></details>"
+    @linter.run(processed_source)
+
+    assert_empty @linter.offenses
+  end
+end

From a10071a7d4706c9d08c9b068f5c2318c59b4a023 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 12:52:57 +0000
Subject: [PATCH 02/15] Use `each_with_index` to get the index of tag

---
 .../linters/github/accessibility/details_has_summary.rb      | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index 9e1bcba..4badb5b 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -13,13 +13,10 @@ class DetailsHasSummary < Linter
           MESSAGE = "<details> elements need to have explict <summary> elements"
 
           def run(processed_source)
-            tags(processed_source).each do |tag|
+            tags(processed_source).each_with_index do |tag, index|
               next if tag.closing?
               next unless tag.name == "details"
 
-              # Find the details element index in the AST
-              index = processed_source.ast.to_a.find_index(tag.node)
-
               # Get the next element in the AST
               next_node = processed_source.ast.to_a[index + 1]
               next_tag = BetterHtml::Tree::Tag.from_node(next_node)

From de0c0880329132b71bd02d7af8995066baf320b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:08:22 +0000
Subject: [PATCH 03/15] Simplify iterating through children

---
 .../accessibility/details_has_summary.rb      | 26 +++++++++++--------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index 4badb5b..94862ae 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -13,18 +13,22 @@ class DetailsHasSummary < Linter
           MESSAGE = "<details> elements need to have explict <summary> elements"
 
           def run(processed_source)
-            tags(processed_source).each_with_index do |tag, index|
-              next if tag.closing?
-              next unless tag.name == "details"
-
-              # Get the next element in the AST
-              next_node = processed_source.ast.to_a[index + 1]
-              next_tag = BetterHtml::Tree::Tag.from_node(next_node)
+            current_details = nil
+            has_summary = false
 
-              # If the next element is a summary, we're good
-              next if next_tag.name == "summary"
-
-              generate_offense(self.class, processed_source, tag)
+            tags(processed_source).each_with_index do |tag, index|
+              if tag.name == "summary" && !tag.closing?
+                has_summary = true
+              end
+
+              next if tag.name != "details"
+
+              if tag.closing? && !has_summary
+                generate_offense(self.class, processed_source, current_details)
+                current_details = nil
+              else
+                current_details = tag
+              end
             end
 
             rule_disabled?(processed_source)

From 43bd2dabe0685cb76a910b702d5bc6ae8059440f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:09:38 +0000
Subject: [PATCH 04/15] Update test name

---
 test/linters/accessibility/details_has_summary_test.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
index b7c0b1d..c3324f6 100644
--- a/test/linters/accessibility/details_has_summary_test.rb
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -14,7 +14,7 @@ def test_warns_if_details_doesnt_have_a_summary
     assert_equal @linter.offenses.count, 1
   end
 
-  def test_does_not_warn_if_only_disabled_attribute_is_set
+  def test_does_not_warn_if_details_has_a_summary
     @file = "<details><summary>Expand me!</summary><button>Surprise button!</button></details>"
     @linter.run(processed_source)
 

From 963ed23bf7c04088855ac8498742fd885726c82c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:09:53 +0000
Subject: [PATCH 05/15] Add a test for when the `<summary>` is in a weird place

---
 test/linters/accessibility/details_has_summary_test.rb | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
index c3324f6..b2278bf 100644
--- a/test/linters/accessibility/details_has_summary_test.rb
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -14,6 +14,13 @@ def test_warns_if_details_doesnt_have_a_summary
     assert_equal @linter.offenses.count, 1
   end
 
+  def test_does_not_warn_if_details_has_a_summary_in_a_weird_place
+    @file = "<details><p>Surprise text!</p><summary>Expand me!</summary></details>"
+    @linter.run(processed_source)
+
+    assert_empty @linter.offenses
+  end
+  
   def test_does_not_warn_if_details_has_a_summary
     @file = "<details><summary>Expand me!</summary><button>Surprise button!</button></details>"
     @linter.run(processed_source)

From 8d42625489b7a71ca116d611cc98ef40d689be0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:16:07 +0000
Subject: [PATCH 06/15] Add docs on the `DetailsHasSummary` rule

---
 README.md                                     |  1 +
 .../accessibility/details-has-summary.md      | 28 +++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 docs/rules/accessibility/details-has-summary.md

diff --git a/README.md b/README.md
index 3a2cf2b..811b9f1 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,7 @@ linters:
 - [GitHub::Accessibility::NoPositiveTabIndex](./docs/rules/accessibility/no-positive-tab-index.md)
 - [GitHub::Accessibility::NoRedundantImageAlt](./docs/rules/accessibility/no-redundant-image-alt.md)
 - [GitHub::Accessibility::NoTitleAttributeCounter](./docs/rules/accessibility/no-title-attribute-counter.md)
+- [GitHub::Accessibility::DetailsHasSummary](./docs/rules/accessibility/details-has-summary.md)
 
 ## Testing
 
diff --git a/docs/rules/accessibility/details-has-summary.md b/docs/rules/accessibility/details-has-summary.md
new file mode 100644
index 0000000..d241486
--- /dev/null
+++ b/docs/rules/accessibility/details-has-summary.md
@@ -0,0 +1,28 @@
+# Details has summary
+
+## Rule Details
+`<details>` should have a `<summary>` element hinting to the user what they'll be expanding by interfacing with the element. This is useful to screen reader users to navigate the website as well as a good UI pattern since omitting a `<summary>` element lets the user agent inject their own `<summary>` element that adds no context to the control.
+
+### 👎 Examples of **incorrect** code for this rule:
+
+```erb
+<details>
+  I don't have a summary tag!
+</details>
+```
+
+### 👍 Examples of **correct** code for this rule:
+
+```erb
+<details>
+  <summary>Expand me!</summary>
+  I do have a summary tag!
+</details>
+````
+
+```erb
+<details>
+  I do have a summary tag!
+  <summary>Expand me!</summary>
+</details>
+````

From 8abd5035b11b42d8ee49e161d44eaed8ba60e6ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:20:14 +0000
Subject: [PATCH 07/15] Update rule description a bit

---
 docs/rules/accessibility/details-has-summary.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/rules/accessibility/details-has-summary.md b/docs/rules/accessibility/details-has-summary.md
index d241486..b2640a2 100644
--- a/docs/rules/accessibility/details-has-summary.md
+++ b/docs/rules/accessibility/details-has-summary.md
@@ -1,7 +1,7 @@
 # Details has summary
 
 ## Rule Details
-`<details>` should have a `<summary>` element hinting to the user what they'll be expanding by interfacing with the element. This is useful to screen reader users to navigate the website as well as a good UI pattern since omitting a `<summary>` element lets the user agent inject their own `<summary>` element that adds no context to the control.
+`<details>` should have a `<summary>` element hinting to the user what they'll be expanding by interfacing with the element. `<summary>` elements are helpful for screen reader users navigating the website. They are also a good UI pattern since a user agent adds their own `<summary>` if a developer omitted it with no context on what UI the details element will expand.
 
 ### 👎 Examples of **incorrect** code for this rule:
 

From aae4f1f344bdbc164a62a91ce14839efd4a8be02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:20:46 +0000
Subject: [PATCH 08/15] Remove unused `each_with_index`

---
 .../linters/github/accessibility/details_has_summary.rb         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index 94862ae..c01c896 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -16,7 +16,7 @@ def run(processed_source)
             current_details = nil
             has_summary = false
 
-            tags(processed_source).each_with_index do |tag, index|
+            tags(processed_source).each do |tag|
               if tag.name == "summary" && !tag.closing?
                 has_summary = true
               end

From bb572de5c23b3296dc28bb1a45e5f47baf5a85f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 13:22:58 +0000
Subject: [PATCH 09/15] Fix rubocop violations

---
 .../linters/github/accessibility/details_has_summary.rb       | 4 +---
 test/linters/accessibility/details_has_summary_test.rb        | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index c01c896..b536532 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -17,9 +17,7 @@ def run(processed_source)
             has_summary = false
 
             tags(processed_source).each do |tag|
-              if tag.name == "summary" && !tag.closing?
-                has_summary = true
-              end
+              has_summary = true if tag.name == "summary" && !tag.closing?
 
               next if tag.name != "details"
 
diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
index b2278bf..7ebf3aa 100644
--- a/test/linters/accessibility/details_has_summary_test.rb
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -20,7 +20,7 @@ def test_does_not_warn_if_details_has_a_summary_in_a_weird_place
 
     assert_empty @linter.offenses
   end
-  
+
   def test_does_not_warn_if_details_has_a_summary
     @file = "<details><summary>Expand me!</summary><button>Surprise button!</button></details>"
     @linter.run(processed_source)

From f4d75a96f54bc870e620accfd066de7fb677d3ea Mon Sep 17 00:00:00 2001
From: Manuel Puyol <manuelpuyol@github.com>
Date: Tue, 15 Mar 2022 10:58:15 -0500
Subject: [PATCH 10/15] Add TagTreeHelpers from PVC to actually build a tag
 tree structure

---
 .../linters/tag_tree_helpers.rb               | 67 +++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 lib/erblint-github/linters/tag_tree_helpers.rb

diff --git a/lib/erblint-github/linters/tag_tree_helpers.rb b/lib/erblint-github/linters/tag_tree_helpers.rb
new file mode 100644
index 0000000..5889f1f
--- /dev/null
+++ b/lib/erblint-github/linters/tag_tree_helpers.rb
@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+module ERBLint
+  module Linters
+    # Helpers used by linters to organize HTML tags into abstract syntax trees.
+    module TagTreeHelpers
+      # from https://github.com/Shopify/erb-lint/blob/6179ee2d9d681a6ec4dd02351a1e30eefa748d3d/lib/erb_lint/linters/self_closing_tag.rb
+      SELF_CLOSING_TAGS = %w[
+        area base br col command embed hr input keygen
+        link menuitem meta param source track wbr img
+      ].freeze
+
+      # This assumes that the AST provided represents valid HTML, where each tag has a corresponding closing tag.
+      # From the tags, we build a structured tree which represents the tag hierarchy.
+      # With this, we are able to know where the tags start and end.
+      def build_tag_tree(processed_source)
+        nodes = processed_source.ast.children
+        tag_tree = {}
+        tags = []
+        current_opened_tag = nil
+
+        nodes.each do |node|
+          tag = BetterHtml::Tree::Tag.from_node(node)
+
+          if node.type == :tag
+            # get the tag from previously calculated list so the references are the same
+            tags << tag
+
+            if tag.closing?
+              if current_opened_tag && tag.name == current_opened_tag.name
+                tag_tree[current_opened_tag][:closing] = tag
+                current_opened_tag = tag_tree[current_opened_tag][:parent]
+              end
+
+              next
+            end
+
+            self_closing = self_closing?(tag)
+
+            tag_tree[tag] = {
+              tag: tag,
+              closing: self_closing ? tag : nil,
+              parent: current_opened_tag,
+              children: []
+            }
+
+            tag_tree[current_opened_tag][:children] << tag_tree[tag] if current_opened_tag
+            current_opened_tag = tag unless self_closing
+          elsif current_opened_tag
+            tag_tree[current_opened_tag][:children] << {
+              tag: tag,
+              closing: tag,
+              parent: current_opened_tag,
+              children: []
+            }
+          end
+        end
+
+        [tags, tag_tree]
+      end
+
+      def self_closing?(tag)
+        tag.self_closing? || SELF_CLOSING_TAGS.include?(tag.name)
+      end
+    end
+  end
+end

From 6491bcc603e6bafbea647b936910068408d37c53 Mon Sep 17 00:00:00 2001
From: Manuel Puyol <manuelpuyol@github.com>
Date: Tue, 15 Mar 2022 10:58:37 -0500
Subject: [PATCH 11/15] Search for details with summaries using the tag_tree

---
 .../accessibility/details_has_summary.rb      | 25 ++++++++++++-------
 .../accessibility/details_has_summary_test.rb |  7 ++++++
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index b536532..a371308 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require_relative "../../custom_helpers"
+require_relative "../../tag_tree_helpers"
 
 module ERBLint
   module Linters
@@ -8,25 +9,31 @@ module GitHub
       module Accessibility
         class DetailsHasSummary < Linter
           include ERBLint::Linters::CustomHelpers
+          include ERBLint::Linters::TagTreeHelpers
           include LinterRegistry
 
           MESSAGE = "<details> elements need to have explict <summary> elements"
 
           def run(processed_source)
-            current_details = nil
             has_summary = false
 
-            tags(processed_source).each do |tag|
-              has_summary = true if tag.name == "summary" && !tag.closing?
+            (tags, tag_tree) = build_tag_tree(processed_source)
 
-              next if tag.name != "details"
+            tags.each do |tag|
+              next if tag.name != "details" || tag.closing?
 
-              if tag.closing? && !has_summary
-                generate_offense(self.class, processed_source, current_details)
-                current_details = nil
-              else
-                current_details = tag
+              details = tag_tree[tag]
+
+              details[:children].each do |child|
+                if child && child[:tag].name == "summary"
+                  has_summary = true
+                  break
+                end
               end
+
+              generate_offense(self.class, processed_source, details[:tag]) unless has_summary
+
+              has_summary = false
             end
 
             rule_disabled?(processed_source)
diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
index 7ebf3aa..df78982 100644
--- a/test/linters/accessibility/details_has_summary_test.rb
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -27,4 +27,11 @@ def test_does_not_warn_if_details_has_a_summary
 
     assert_empty @linter.offenses
   end
+
+  def test_does_warns_if_details_has_a_summary_as_an_inner_child
+    @file = "<details><p><summary>Expand me!</summary></p><button>Surprise button!</button></details>"
+    @linter.run(processed_source)
+
+    assert_equal @linter.offenses.count, 1
+  end
 end

From afd2917331abe2c0b7c96f379b27889ef9b9c0b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Tue, 15 Mar 2022 16:04:52 +0000
Subject: [PATCH 12/15] Add another incorrect example

---
 docs/rules/accessibility/details-has-summary.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/docs/rules/accessibility/details-has-summary.md b/docs/rules/accessibility/details-has-summary.md
index b2640a2..bb671b0 100644
--- a/docs/rules/accessibility/details-has-summary.md
+++ b/docs/rules/accessibility/details-has-summary.md
@@ -11,6 +11,13 @@
 </details>
 ```
 
+```erb
+<details>
+  <div><summary>Expand me!</summary></div>
+  I have a invalid summary tag! The summary tag needs to be a direct child of the details tag.
+</details>
+```
+
 ### 👍 Examples of **correct** code for this rule:
 
 ```erb

From 185195f9ae4fb46e3b4595871b27eb6b079d9856 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@github.com>
Date: Wed, 16 Mar 2022 10:26:07 +0000
Subject: [PATCH 13/15] fix speling

Co-authored-by: Kate Higa  <16447748+khiga8@users.noreply.github.com>
---
 .../linters/github/accessibility/details_has_summary.rb         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index a371308..6fb3ce0 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -12,7 +12,7 @@ class DetailsHasSummary < Linter
           include ERBLint::Linters::TagTreeHelpers
           include LinterRegistry
 
-          MESSAGE = "<details> elements need to have explict <summary> elements"
+          MESSAGE = "<details> elements need to have explicit <summary> element"
 
           def run(processed_source)
             has_summary = false

From 3a802dcc4f4e41f8ef2ca3b81804b9f13d8c0b9e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kristj=C3=A1n=20Oddsson?= <koddsson@gmail.com>
Date: Thu, 17 Mar 2022 14:08:32 +0000
Subject: [PATCH 14/15] Add a test for tag_tree_helpers

---
 test/linters/tag_tree_helpers_test.rb | 41 +++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 test/linters/tag_tree_helpers_test.rb

diff --git a/test/linters/tag_tree_helpers_test.rb b/test/linters/tag_tree_helpers_test.rb
new file mode 100644
index 0000000..f4fdf82
--- /dev/null
+++ b/test/linters/tag_tree_helpers_test.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require_relative "../../lib/erblint-github/linters/tag_tree_helpers"
+
+class TagTreeHelpers < Minitest::Test
+  include ERBLint::Linters::TagTreeHelpers
+
+  def test_build_tree
+    file = %{
+      <html>
+        <head>
+          <title>Hello</title>
+        </head>
+        <body>
+          <h1>Hello</h1>
+          Welcome to my page!
+        </body>
+      </html>
+    }
+    processed_source = ERBLint::ProcessedSource.new("file.rb", file)
+    tags, tree = build_tag_tree(processed_source)
+
+    html_tag = tags.first
+
+    assert_equal "html", html_tag.name
+
+    children = tree[html_tag][:children].filter do |child|
+      child[:tag].name
+    end
+
+    assert_equal 2, children.length
+    assert_equal "head", children[0][:tag].name
+
+    body_tag = children[1][:tag]
+    assert_equal "body", body_tag.name
+
+    h1_tag = tree[body_tag][:children].filter{ |child| child[:tag].name }.first[:tag]
+    assert_equal "h1", h1_tag.name
+  end
+end

From 4e12784e36a2da4b331f536829622fa7ed292abf Mon Sep 17 00:00:00 2001
From: Manuel Puyol <manuelpuyol@github.com>
Date: Tue, 22 Mar 2022 10:59:44 -0500
Subject: [PATCH 15/15] add tests for content_tag

---
 .../accessibility/details_has_summary.rb      | 36 +++++++++++++++-
 .../accessibility/details_has_summary_test.rb | 42 ++++++++++++++++++-
 2 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
index 6fb3ce0..03a6ae7 100644
--- a/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
+++ b/lib/erblint-github/linters/github/accessibility/details_has_summary.rb
@@ -25,7 +25,28 @@ def run(processed_source)
               details = tag_tree[tag]
 
               details[:children].each do |child|
-                if child && child[:tag].name == "summary"
+                if child[:tag].name == "summary"
+                  has_summary = true
+                  break
+                end
+
+                erb_nodes = extract_erb_nodes(child[:tag].node)
+
+                next if erb_nodes.blank?
+
+                code = ""
+
+                erb_nodes.each do |erb_node|
+                  _, _, code_node = *erb_node
+                  code += code_node.children.first
+                end
+
+                ast = erb_ast(code)
+
+                ast = ast.children.first if ast.type == :block
+                next unless ast.method_name == :content_tag
+
+                if ast.arguments.first.value.to_s == "summary"
                   has_summary = true
                   break
                 end
@@ -38,6 +59,19 @@ def run(processed_source)
 
             rule_disabled?(processed_source)
           end
+
+          private
+
+          def extract_erb_nodes(node)
+            return node if node.type == :erb
+            return nil unless node.type == :text
+
+            node.children.select { |x| x.try(:type) == :erb }
+          end
+
+          def erb_ast(code)
+            RuboCop::AST::ProcessedSource.new(code, RUBY_VERSION.to_f).ast
+          end
         end
       end
     end
diff --git a/test/linters/accessibility/details_has_summary_test.rb b/test/linters/accessibility/details_has_summary_test.rb
index df78982..54324c1 100644
--- a/test/linters/accessibility/details_has_summary_test.rb
+++ b/test/linters/accessibility/details_has_summary_test.rb
@@ -11,7 +11,7 @@ def test_warns_if_details_doesnt_have_a_summary
     @file = "<details>I don't have a summary element</details>"
     @linter.run(processed_source)
 
-    assert_equal @linter.offenses.count, 1
+    assert_equal 1, @linter.offenses.count
   end
 
   def test_does_not_warn_if_details_has_a_summary_in_a_weird_place
@@ -32,6 +32,44 @@ def test_does_warns_if_details_has_a_summary_as_an_inner_child
     @file = "<details><p><summary>Expand me!</summary></p><button>Surprise button!</button></details>"
     @linter.run(processed_source)
 
-    assert_equal @linter.offenses.count, 1
+    assert_equal 1, @linter.offenses.count
+  end
+
+  def test_doesnt_warns_if_details_has_a_summary_content_tag
+    @file = <<~ERB
+      <details>
+        <%= content_tag(:summary) { "Expand me!" } %>
+        <p>Surprise text!</p>
+      </details>
+    ERB
+    @linter.run(processed_source)
+
+    assert_empty @linter.offenses
+  end
+
+  def test_doesnt_warns_if_details_has_a_summary_content_tag_with_do_block
+    @file = <<~ERB
+      <details>
+        <%= content_tag(:summary) do %>
+          Expand me!
+        <% end %>
+        <p>Surprise text!</p>
+      </details>
+    ERB
+    @linter.run(processed_source)
+
+    assert_empty @linter.offenses
+  end
+
+  def test_warns_if_details_has_a_non_summary_content_tag
+    @file = <<~ERB
+      <details>
+        <%= content_tag(:div) { "Expand me!" } %>
+        <p>Surprise text!</p>
+      </details>
+    ERB
+    @linter.run(processed_source)
+
+    assert_equal 1, @linter.offenses.count
   end
 end