Fix edge cases where expression includes delimiters

grammar.js

@@ -99,7 +99,16 @@ module.exports = grammar({
       ),
 
     _expression_value: ($) =>
-      choice(/[^{}]+/, seq("{", optional($._expression_value), "}")),
+      // Note that we alias "{" and "}", so they are not targetted by
+      // delimiter highlight queries.
+      choice(
+        /[^{}]+/,
+        seq(
+          alias("{", "left"),
+          repeat($._expression_value),
+          alias("}", "right")
+        )
+      ),
 
     special_attribute: ($) => seq($.special_attribute_name, "=", $.expression),
 

queries/injections.scm

@@ -20,5 +20,8 @@
 
 ; expressions live within HTML tags, and do not need to be combined
 ;     <link href={ Routes.static_path(..) } />
+; note that we include children, because expression_value may consist
+; of multiple nodes, when the value contains { and }
 ((expression (expression_value) @injection.content)
- (#set! injection.language "elixir"))
+ (#set! injection.language "elixir")
+ (#set! injection.include-children))