Add Openbox pipe menu renderer

render/1 turns a list of #desktop_entry{} into the XML Openbox expects
on stdout from a pipe menu: hidden entries dropped, remaining ones
sorted case-insensitively by name, each as an <item> wrapping an
Execute action with its command and (if present) icon attribute.
XML-escapes label/command/icon values.

Icon values are passed through as-is (theme icon names, not resolved
paths) -- icon theme resolution is left for later, separate from
rendering. Service wiring (scan -> parse -> render, with caching and
invalidation) is also left for later.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 96 insertions, 0 deletions

diff --git a/test/er_xdg_pipe_menu_renderer_tests.erl b/test/er_xdg_pipe_menu_renderer_tests.erl
new file mode 100644
index 0000000..1fc0192
--- /dev/null
+++ b/test/er_xdg_pipe_menu_renderer_tests.erl
@@ -0,0 +1,96 @@
+-module(er_xdg_pipe_menu_renderer_tests).
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("xmerl/include/xmerl.hrl").
+-include("er_xdg_pipe_menu.hrl").
+
+entry(Name, Exec, Icon) ->
+    entry(Name, Exec, Icon, false).
+
+entry(Name, Exec, Icon, Hidden) ->
+    #desktop_entry{name = Name, exec = Exec, icon = Icon, hidden = Hidden}.
+
+empty_list_renders_empty_menu_test() ->
+    ?assertEqual(
+        <<"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+          "<openbox_pipe_menu>\n"
+          "</openbox_pipe_menu>\n">>,
+        er_xdg_pipe_menu_renderer:render([])
+    ).
+
+single_entry_with_icon_test() ->
+    Rendered = er_xdg_pipe_menu_renderer:render([entry(<<"Firefox">>, <<"firefox">>, <<"firefox">>)]),
+    ?assertEqual(
+        <<"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+          "<openbox_pipe_menu>\n"
+          "  <item label=\"Firefox\" icon=\"firefox\">\n"
+          "    <action name=\"Execute\">\n"
+          "      <command>firefox</command>\n"
+          "    </action>\n"
+          "  </item>\n"
+          "</openbox_pipe_menu>\n">>,
+        Rendered
+    ).
+
+entry_without_icon_omits_icon_attr_test() ->
+    Rendered = er_xdg_pipe_menu_renderer:render([entry(<<"Foo">>, <<"foo">>, undefined)]),
+    ?assertEqual(
+        <<"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+          "<openbox_pipe_menu>\n"
+          "  <item label=\"Foo\">\n"
+          "    <action name=\"Execute\">\n"
+          "      <command>foo</command>\n"
+          "    </action>\n"
+          "  </item>\n"
+          "</openbox_pipe_menu>\n">>,
+        Rendered
+    ).
+
+hidden_entries_are_dropped_test() ->
+    Entries = [
+        entry(<<"Visible">>, <<"visible">>, undefined),
+        entry(<<"Invisible">>, <<"invisible">>, undefined, true)
+    ],
+    Rendered = er_xdg_pipe_menu_renderer:render(Entries),
+    ?assertNot(binary:match(Rendered, <<"Invisible">>) =/= nomatch),
+    ?assert(binary:match(Rendered, <<"Visible">>) =/= nomatch).
+
+entries_are_sorted_case_insensitively_test() ->
+    Entries = [
+        entry(<<"zeta">>, <<"zeta">>, undefined),
+        entry(<<"Alpha">>, <<"alpha">>, undefined),
+        entry(<<"beta">>, <<"beta">>, undefined)
+    ],
+    Rendered = er_xdg_pipe_menu_renderer:render(Entries),
+    Positions = [
+        element(1, binary:match(Rendered, <<"label=\"Alpha\"">>)),
+        element(1, binary:match(Rendered, <<"label=\"beta\"">>)),
+        element(1, binary:match(Rendered, <<"label=\"zeta\"">>))
+    ],
+    ?assertEqual(Positions, lists:sort(Positions)).
+
+escapes_special_characters_test() ->
+    Entry = entry(<<"Foo & <Bar> \"Baz\"">>, <<"foo --title=\"<x>&y\"">>, <<"icon\"&<>">>),
+    Rendered = er_xdg_pipe_menu_renderer:render([Entry]),
+    ?assertEqual(
+        <<"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+          "<openbox_pipe_menu>\n"
+          "  <item label=\"Foo &amp; &lt;Bar&gt; &quot;Baz&quot;\" icon=\"icon&quot;&amp;&lt;&gt;\">\n"
+          "    <action name=\"Execute\">\n"
+          "      <command>foo --title=\"&lt;x&gt;&amp;y\"</command>\n"
+          "    </action>\n"
+          "  </item>\n"
+          "</openbox_pipe_menu>\n">>,
+        Rendered
+    ).
+
+output_is_well_formed_xml_test() ->
+    Entries = [
+        entry(<<"Firefox">>, <<"firefox">>, <<"firefox">>),
+        entry(<<"Foo & Bar">>, <<"foo">>, undefined)
+    ],
+    Rendered = er_xdg_pipe_menu_renderer:render(Entries),
+    {Doc, _Rest} = xmerl_scan:string(binary_to_list(Rendered)),
+    ?assertEqual(openbox_pipe_menu, Doc#xmlElement.name),
+    Items = [E || E = #xmlElement{name = item} <- Doc#xmlElement.content],
+    ?assertEqual(2, length(Items)).