handle closing interpolation without opening brace in attrs (#4129)

Closes #4117.

Author: SteffenDE

lib/phoenix_live_view/tag_engine/tokenizer.ex

@@ -491,6 +491,10 @@ defmodule Phoenix.LiveView.TagEngine.Tokenizer do
 
   ## handle_attr_name
 
+  defp handle_attr_name(<<"}"::utf8, _rest::binary>>, column, _buffer) do
+    {:error, "expected attribute, but found end of interpolation: }", column}
+  end
+
   defp handle_attr_name(<<c::utf8, _rest::binary>>, column, _buffer)
        when c in @quote_chars do
     {:error, "invalid character in attribute name: #{<<c>>}", column}

test/phoenix_live_view/html_engine_test.exs

@@ -738,14 +738,14 @@ defmodule Phoenix.LiveView.HTMLEngineTest do
       test/phoenix_live_view/html_engine_test.exs:2:38: unsupported attribute \":bar\" in local component: local_function_component
         |
       1 | <br>
-      2 | <.local_function_component value='1' :bar=\"1\"}
+      2 | <.local_function_component value='1' :bar=\"1\" />
         |                                      ^\
       """
 
       assert_raise(ParseError, message, fn ->
         eval("""
         <br>
-        <.local_function_component value='1' :bar="1"}
+        <.local_function_component value='1' :bar="1" />
         />
         """)
       end)

…hoenix_live_view/heex/tokenizer_test.exs …_live_view/tag_engine/tokenizer_test.exstest/phoenix_live_view/heex/tokenizer_test.exs renamed to test/phoenix_live_view/tag_engine/tokenizer_test.exs test/phoenix_live_view/heex/tokenizer_test.exs renamed to test/phoenix_live_view/tag_engine/tokenizer_test.exs

@@ -443,6 +443,19 @@ defmodule Phoenix.LiveView.TagEngine.TokenizerTest do
         tokenize(~S(<div class={"test"}">))
       end
     end
+
+    test "raise on missing opening interpolation" do
+      message = """
+      nofile:1:29: expected attribute, but found end of interpolation: }
+        |
+      1 | <div class=\"image-container\"}>
+        |                             ^\
+      """
+
+      assert_raise ParseError, message, fn ->
+        tokenize(~S(<div class="image-container"}>))
+      end
+    end
   end
 
   describe "boolean attributes" do