Autolink emails and URLs at rendering time

test/helpers/html_helper_test.rb

@@ -0,0 +1,35 @@
+require "test_helper"
+
+class HtmlHelperTest < ActionView::TestCase
+  test "converts URLs into anchor tags" do
+    assert_equal_html \
+      %(<p>Check this: <a href="https://example.com" rel="noreferrer">https://example.com</a></p>),
+      format_html("<p>Check this: https://example.com</p>")
+  end
+
+  test "respect existing links" do
+    assert_equal_html \
+      %(<p>Check this: <a href="https://example.com">https://example.com</a></p>),
+      format_html("<p>Check this: <a href=\"https://example.com\">https://example.com</a></p>")
+  end
+
+  test "converts email addresses into mailto links" do
+    assert_equal_html \
+      %(<p>Contact us at <a href="mailto:support@example.com">support@example.com</a></p>),
+      format_html("<p>Contact us at support@example.com</p>")
+  end
+
+  test "respect existing linked emails" do
+    assert_equal_html \
+      %(<p>Contact us at <a href="mailto:support@example.com">support@example.com</a></p>),
+      format_html(%(<p>Contact us at <a href="mailto:support@example.com">support@example.com</a></p>))
+  end
+
+  test "don't autolink content in excluded elements" do
+    %w[ figcaption pre code ].each do |element|
+      assert_equal_html \
+        "<#{element}>Check this: https://example.com</#{element}>",
+        format_html("<#{element}>Check this: https://example.com</#{element}>")
+    end
+  end
+end