Actions: tolerate long ${{ ... }} expressions

actions/ql/lib/codeql/actions/ast/internal/Ast.qll

@@ -27,8 +27,8 @@ string getADelimitedExpression(YamlString s, int offset) {
   // not just the last (greedy match) or first (reluctant match).
   result =
     s.getValue()
-        .regexpFind("\\$\\{\\{(?:[^}]|}(?!}))*\\}\\}", _, offset)
-        .regexpCapture("(\\$\\{\\{(?:[^}]|}(?!}))*\\}\\})", 1)
+        .regexpFind("\\$\\{\\{(?:[^}]|}(?!}))*+\\}\\}", _, offset)
+        .regexpCapture("(\\$\\{\\{(?:[^}]|}(?!}))*+\\}\\})", 1)
         .trim()
 }
 

actions/ql/test/library-tests/very-long-expression/very_long_expression_node.expected

@@ -0,0 +1 @@
+| 97418 |

actions/ql/test/library-tests/very-long-expression/very_long_expression_node.ql

@@ -0,0 +1,5 @@
+import codeql.actions.ast.internal.Ast
+
+int getAnExpressionLength() { result = any(ExpressionImpl e).toString().length() }
+
+select max(getAnExpressionLength())