document attr values/examples event when there is a default (#3745)

Author: thecristen

lib/phoenix_component/declarative.ex

@@ -982,12 +982,19 @@ defmodule Phoenix.Component.Declarative do
     end
   end
 
-  defp build_attr_values_or_examples(%{opts: [values: values]}) do
-    ["Must be one of ", build_literals_list(values, "or"), ?.]
-  end
+  defp build_attr_values_or_examples(%{opts: opts} = attr) do
+    space_before = if attr[:doc] || opts[:default], do: ?\s, else: []
+
+    cond do
+      Keyword.get(opts, :values) ->
+        [space_before, "Must be one of ", build_literals_list(opts[:values], "or"), ?.]
+
+      Keyword.get(opts, :examples) ->
+        [space_before, "Examples include ", build_literals_list(opts[:examples], "and"), ?.]
 
-  defp build_attr_values_or_examples(%{opts: [examples: examples]}) do
-    ["Examples include ", build_literals_list(examples, "and"), ?.]
+      true ->
+        []
+    end
   end
 
   defp build_attr_values_or_examples(_attr) do

test/phoenix_component/declarative_assigns_test.exs

@@ -1060,6 +1060,9 @@ defmodule Phoenix.ComponentDeclarativeAssignsTest do
       * `attr2` (`:atom`) - Examples include `:foo`, `:bar`, and `:baz`.
       * `attr3` (`:list`) - Must be one of `[60, 40]`.
       * `attr4` (`:list`) - Examples include `[60, 40]`.
+      * `attr5` (`:atom`) - Defaults to `:foo`. Must be one of `:foo`, `:bar`, or `:baz`.
+      * `attr6` (`:atom`) - Attr 6 doc. Must be one of `:foo`, `:bar`, or `:baz`.
+      * `attr7` (`:atom`) - Attr 7 doc. Defaults to `:foo`. Must be one of `:foo`, `:bar`, or `:baz`.
       """
     }
 

test/support/live_views/components.ex

@@ -179,7 +179,9 @@ defmodule Phoenix.LiveViewTest.Support.FunctionComponentWithAttrs do
   attr :attr2, :atom, examples: [:foo, :bar, :baz]
   attr :attr3, :list, values: [[60, 40]]
   attr :attr4, :list, examples: [[60, 40]]
-
+  attr :attr5, :atom, default: :foo, values: [:foo, :bar, :baz]
+  attr :attr6, :atom, doc: "Attr 6 doc", values: [:foo, :bar, :baz]
+  attr :attr7, :atom, doc: "Attr 7 doc", default: :foo, values: [:foo, :bar, :baz]
   def fun_attr_values_examples(assigns), do: ~H[]
 end