Enforce invalid mapping diagnostic

2 files changed, 12 insertions, 1 deletions

diff --git a/lua/clever_f/sequence_coordinator.lua b/lua/clever_f/sequence_coordinator.lua
index a83c75f..0f233cf 100644
--- a/lua/clever_f/sequence_coordinator.lua
+++ b/lua/clever_f/sequence_coordinator.lua
@@ -31,7 +31,7 @@ end
 function M.validate_primary_descriptor(value)
   local descriptor = domain.Descriptor.try_from_string(value)
   if descriptor == nil then
-    fail("clever-f: Invalid mapping '" .. descriptor_text(value) .. "'", 2)
+    error("clever-f: Invalid mapping '" .. descriptor_text(value) .. "'", 0)
   end
   return descriptor
 end
diff --git a/tests/run.lua b/tests/run.lua
index 08771db..66816bb 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -7858,6 +7858,17 @@ test("Free-form action adapter accepts every valid descriptor", function()
   end
 end)
 
+test("Free-form action adapter raises the exact invalid mapping error", function()
+  fresh_sequence_state()
+  local root = composition_root.new({ host = MemoryHost.new() })
+  local ok, diagnostic = pcall(function()
+    root:invoke_descriptor("X")
+  end)
+
+  falsy(ok)
+  same("clever-f: Invalid mapping 'X'", diagnostic)
+end)
+
 test("ActionFacade returns typed primary action outcomes", function()
   fresh_sequence_state()
   local host = MemoryHost.new({