Fix back navigation from filter views to cards (#2725)

* test: update sign_in_as system test helper to be more generic

and support fixture users with more than one board

* test: backfill a test for the card "back link"

when coming from a board filter page

* Fix back navigation to filter views from cards

When navigating from a filter view to a card, the back link now shows
the filter's label and navigates back to the filter URL instead of the
card's board.

The turbo-navigation Stimulus controller stores the page title alongside
the referrer URL in sessionStorage. On the card show page, a
referrerBackLink target rewrites the back link's href and label from the
stored values. This is scoped only to the card show page to avoid
navigation loops in multi-level deep pages.

* Add referrer allowlist to prevent stale referrer rewrites

The back link is only rewritten when the stored referrer's path matches
an allowlist of paths passed via prefer_referrer. This prevents stale
referrers from unrelated pages (e.g., settings) from overriding the
card's back link.

* Move back link navigation tests to dedicated system test file

Extract back link tests from smoke_test.rb into their own file since
they test specific JavaScript behavior that needs regression coverage.
Move sign_in_as helper to ApplicationSystemTestCase for reuse.

* Move markdown paste tests to dedicated system test file

test/application_system_test_case.rb

@@ -28,4 +28,10 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
   else
     driven_by :chrome_headless, screen_size: [ 1200, 1000 ]
   end
+
+  private
+    def sign_in_as(user)
+      visit session_transfer_url(user.identity.transfer_id, script_name: nil)
+      assert_current_path root_path
+    end
 end

test/system/back_link_navigation_test.rb

@@ -0,0 +1,38 @@
+require "application_system_test_case"
+
+class BackLinkNavigationTest < ApplicationSystemTestCase
+  test "card back link returns to board filter view when navigating from it" do
+    sign_in_as(users(:david))
+
+    filter_url = board_url(boards(:writebook), creator_ids: [ users(:david).id ])
+    visit filter_url
+    click_on cards(:logo).title
+
+    back_link = find("a.btn--back")
+    assert_selector "a.btn--back strong", text: "Back to Writebook"
+    back_link.click
+    assert_current_path filter_url, ignore_query: false
+  end
+
+  test "card back link returns to global filter view when navigating from it" do
+    sign_in_as(users(:kevin))
+
+    filter_url = cards_url(creator_ids: [ users(:kevin).id ])
+    visit filter_url
+    click_on cards(:text).title
+
+    assert_selector "a.btn--back strong", text: "Back to all boards"
+    find("a.btn--back").click
+    assert_current_path filter_url, ignore_query: false
+  end
+
+  test "card back link is not rewritten when navigating from a non-filter page" do
+    sign_in_as(users(:david))
+
+    visit account_settings_url
+    click_on "Invite people"
+    visit card_url(cards(:logo))
+
+    assert_selector "a.btn--back strong", text: "Back to Writebook"
+  end
+end

test/system/markdown_paste_test.rb

@@ -0,0 +1,44 @@
+require "application_system_test_case"
+
+class MarkdownPasteTest < ApplicationSystemTestCase
+  test "markdown paste adds block spacing" do
+    sign_in_as(users(:david))
+
+    visit card_url(cards(:layout))
+    find("lexxy-editor").click
+    paste_markdown("Hello\n\nWorld")
+
+    within("lexxy-editor") do
+      assert_selector "p", text: "Hello"
+      assert_selector "p br", visible: :all
+      assert_selector "p", text: "World"
+    end
+  end
+
+  test "markdown paste preserves line breaks" do
+    sign_in_as(users(:david))
+
+    visit card_url(cards(:layout))
+    find("lexxy-editor").click
+    paste_markdown("Hello\nWorld")
+
+    inner_html = find("lexxy-editor p", text: "Hello").native.property("innerHTML")
+    children = Nokogiri::HTML5.fragment(inner_html).children
+    assert_pattern do
+      children => [
+        { name: "span", inner_html: "Hello" },
+        { name: "br" },
+        { name: "span", inner_html: "World" }
+      ]
+    end
+  end
+
+  private
+    def paste_markdown(markdown)
+      page.execute_script(<<~JS, markdown)
+        const dt = new DataTransfer();
+        dt.setData("text/plain", arguments[0]);
+        document.activeElement.dispatchEvent(new ClipboardEvent("paste", { clipboardData: dt, bubbles: true }));
+      JS
+    end
+end

test/system/smoke_test.rb

@@ -76,38 +76,6 @@ class SmokeTest < ApplicationSystemTestCase
     assert_no_selector "div##{dom_id(notification)}"
   end
 
-  test "markdown paste adds block spacing" do
-    sign_in_as(users(:david))
-
-    visit card_url(cards(:layout))
-    find("lexxy-editor").click
-    paste_markdown("Hello\n\nWorld")
-
-    within("lexxy-editor") do
-      assert_selector "p", text: "Hello"
-      assert_selector "p br", visible: :all
-      assert_selector "p", text: "World"
-    end
-  end
-
-  test "markdown paste preserves line breaks" do
-    sign_in_as(users(:david))
-
-    visit card_url(cards(:layout))
-    find("lexxy-editor").click
-    paste_markdown("Hello\nWorld")
-
-    inner_html = find("lexxy-editor p", text: "Hello").native.property("innerHTML")
-    children = Nokogiri::HTML5.fragment(inner_html).children
-    assert_pattern do
-      children => [
-        { name: "span", inner_html: "Hello" },
-        { name: "br" },
-        { name: "span", inner_html: "World" }
-      ]
-    end
-  end
-
   test "dragging card to a new column" do
     sign_in_as(users(:david))
 
@@ -127,22 +95,9 @@ class SmokeTest < ApplicationSystemTestCase
   end
 
   private
-    def sign_in_as(user)
-      visit session_transfer_url(user.identity.transfer_id, script_name: nil)
-      assert_selector "h1", text: "Latest Activity"
-    end
-
     def fill_in_lexxy(selector = "lexxy-editor", with:)
       editor_element = find(selector)
       editor_element.set with
       page.execute_script("arguments[0].value = '#{with}'", editor_element)
     end
-
-    def paste_markdown(markdown)
-      page.execute_script(<<~JS, markdown)
-        const dt = new DataTransfer();
-        dt.setData("text/plain", arguments[0]);
-        document.activeElement.dispatchEvent(new ClipboardEvent("paste", { clipboardData: dt, bubbles: true }));
-      JS
-    end
 end