Raise when multiple links found Static pages

What changed?
=============

We update our `Query.find/3` result to differentiate between finding one
or many elements.

Since we now do that, we can improve our assertions. But we also bring
the static and LiveView behavior up to par in a place where we had a
difference.

LiveView raises when we find multiple elements that have the same
selector and text. So, it requires users to find a unique element.

Our Static implementation would simply follow the first link (if many
were found) instead of raising. We now update the code to raise if we
find many -- matching the LiveView behavior.

lib/phoenix_test/assertions.ex

@@ -47,6 +47,13 @@ defmodule PhoenixTest.Assertions do
 
         #{format_found_element(element)}
         """
+
+      {:found_many, elements} ->
+        raise """
+        Expected not to find an element.
+
+        But found #{Enum.count(elements)} elements with selector #{inspect(selector)} and text #{inspect(text)}:
+        """
     end
   end
 

lib/phoenix_test/query.ex

@@ -38,6 +38,14 @@ defmodule PhoenixTest.Query do
 
       {:found, element} ->
         element
+
+      {:found_many, _elements} ->
+        msg =
+          """
+          Found more than one element with selector #{inspect(selector)} and text #{inspect(text)}.
+          """
+
+        raise ArgumentError, msg
     end
   end
 
@@ -81,21 +89,10 @@ defmodule PhoenixTest.Query do
 
       {:found, found_element} ->
         found_element
-    end
-  end
 
-  defp find_with_text(html, selector, text) do
-    elements_matched_selector =
-      html
-      |> Html.all(selector)
-
-    Enum.find(elements_matched_selector, :not_found, fn element ->
-      Html.text(element) =~ text
-    end)
-    |> then(fn
-      :not_found -> {:not_found, elements_matched_selector}
-      found -> {:found, found}
-    end)
+      {:found_many, [found_element | _]} ->
+        found_element
+    end
   end
 
   defp find_one_of(html, elements) do
@@ -110,9 +107,22 @@ defmodule PhoenixTest.Query do
     |> Enum.find({:not_found, elements}, fn
       {:not_found, _} -> false
       {:found, _} -> true
+      {:found_many, _} -> true
     end)
   end
 
+  defp find_with_text(html, selector, text) do
+    elements_matched_selector = Html.all(html, selector)
+
+    elements_matched_selector
+    |> Enum.filter(fn element -> Html.text(element) =~ text end)
+    |> case do
+      [] -> {:not_found, elements_matched_selector}
+      [found] -> {:found, found}
+      [_ | _] = found_many -> {:found_many, found_many}
+    end
+  end
+
   defp first(html, selector) do
     html
     |> Html.all(selector)

test/phoenix_test/assertions_test.exs

@@ -118,9 +118,7 @@ defmodule PhoenixTest.AssertionsTest do
       msg = """
       Expected not to find an element.
 
-      But found an element with selector ".multiple_links" and text "Multiple links":
-
-      <a> with content "Multiple links"
+      But found 2 elements with selector ".multiple_links" and text "Multiple links":
       """
 
       assert_raise RuntimeError, msg, fn ->

test/phoenix_test/static_test.exs

@@ -37,11 +37,12 @@ defmodule PhoenixTest.StaticTest do
       |> assert_has("h1", "Page 2")
     end
 
-    test "follows first link when there are multiple links with same text", %{conn: conn} do
-      conn
-      |> visit("/page/index")
-      |> click_link("Multiple links")
-      |> assert_has("h1", "Page 3")
+    test "raises error when there are multiple links with same text", %{conn: conn} do
+      assert_raise ArgumentError, ~r/Found more than one element with selector/, fn ->
+        conn
+        |> visit("/page/index")
+        |> click_link("Multiple links")
+      end
     end
 
     test "handles navigation to a LiveView", %{conn: conn} do