From 422691344e99d4d63ca213922da90e42343e2332 Mon Sep 17 00:00:00 2001
From: Lilith Hafner <Lilith.Hafner@gmail.com>
Date: Sat, 23 Sep 2023 16:19:40 -0500
Subject: [PATCH] Fix numargs for ComposedFunction

---
 src/utils.jl                             | 2 ++
 test/function_building_error_messages.jl | 5 +++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/utils.jl b/src/utils.jl
index d013c9ac9d..7f5f4b8246 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -27,6 +27,8 @@ function numargs(f::RuntimeGeneratedFunctions.RuntimeGeneratedFunction{
     (length(T),)
 end
 
+numargs(f::ComposedFunction) = numargs(f.inner)
+
 """
 $(SIGNATURES)
 
diff --git a/test/function_building_error_messages.jl b/test/function_building_error_messages.jl
index 269985a397..924c342e51 100644
--- a/test/function_building_error_messages.jl
+++ b/test/function_building_error_messages.jl
@@ -7,10 +7,11 @@ function test_num_args()
     numpar = SciMLBase.numargs(f) # Should be [1,2]
     g = (x, y) -> x^2
     numpar2 = SciMLBase.numargs(g) # [2]
+    numpar3 = SciMLBase.numargs(sqrt ∘ g) # [2]
     @show numpar, minimum(numpar) == 1, maximum(numpar) == 2
     minimum(numpar) == 1 && maximum(numpar) == 2 &&
         maximum(numpar2) == 2 &&
-        minimum(numpar2) == 2
+        only(numpar3) == 2
 end
 
 @test test_num_args()
@@ -614,7 +615,7 @@ bvjp(u, v, p, t) = [1.0]
 @test_throws SciMLBase.NonconformingFunctionsError BVPFunction(bfoop, bciip, vjp = bvjp)
 bvjp(du, u, v, p, t) = [1.0]
 BVPFunction(bfiip, bciip, vjp = bvjp)
-  
+
 @test_throws SciMLBase.NonconformingFunctionsError BVPFunction(bfoop, bciip, vjp = bvjp)
 
 # IntegralFunction