deps_of_all_optional: add tests proving unneeded optional deps are now also discarded

lua/lazy/core/plugin.lua

@@ -240,7 +240,7 @@ function Spec:fix_disabled()
     end
   end
 
-  -- fix deps of plugins that are all optional
+  -- fix deps of plugins that are completely optional
   self:fix_dependencies(all_optional_deps, dep_of, function(dep_name)
     self.plugins[dep_name] = nil
   end)

tests/core/plugin_spec.lua

@@ -273,6 +273,25 @@ describe("plugin spec opt", function()
       end
     end
   end)
+
+  it("handles the optional keyword", function()
+    local tests = {
+      [{ { "foo/bax" }, { "foo/bar", optional = true, dependencies = "foo/dep1" } }] = false,
+      [{ { "foo/bax", dependencies = "foo/dep1" }, { "foo/bar", optional = true, dependencies = "foo/dep1" } }] = true,
+    }
+    for test, ret in pairs(tests) do
+      local spec = Plugin.Spec.new(test)
+      assert(#spec.notifs == 0)
+      assert(spec.plugins.bax)
+      assert(not spec.plugins.bar)
+      assert(#spec.disabled == 0)
+      if ret then
+        assert(spec.plugins.dep1)
+      else
+        assert(not spec.plugins.opt1)
+      end
+    end
+  end)
 end)
 
 describe("plugin opts", function()