Update sjsonnet/test/src/sjsonnet/TailCallOptimizationTests.scala

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: He-Pin

sjsonnet/test/src/sjsonnet/TailCallOptimizationTests.scala

@@ -131,6 +131,22 @@ object TailCallOptimizationTests extends TestSuite {
       ) ==> ujson.Arr(ujson.Num(0), ujson.Num(2), ujson.Num(4), ujson.Num(6), ujson.Num(8))
     }
 
+    test("tailstrictBuiltinFilter") {
+      // Verify that a builtin using the evalRhs/scope-reuse fast path (std.filter)
+      // correctly resolves TailCall produced by a user callback that uses tailstrict.
+      eval(
+        """
+          |std.filter(
+          |  function(x)
+          |    local f(n) =
+          |      if n <= 0 then true
+          |      else f(n - 1) tailstrict;
+          |    f(1000),
+          |  [1]
+          |)
+          |""".stripMargin
+      ) ==> ujson.Arr(ujson.Num(1))
+    }
     test("tailstrictZeroArgs") {
       // Apply0: zero-argument tailstrict call
       eval(