From baf44ddb58c95824d0015f8186689f082e2fe2e3 Mon Sep 17 00:00:00 2001
From: Avik Pal <avikpal@mit.edu>
Date: Sat, 4 Nov 2023 15:50:14 -0400
Subject: [PATCH] Add a default for NLLS

---
 Project.toml                    |  2 +-
 src/default.jl                  | 21 +++++++++++++++------
 test/nonlinear_least_squares.jl |  1 +
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Project.toml b/Project.toml
index 6411e91a5..076596ee4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "NonlinearSolve"
 uuid = "8913a72c-1f9b-4ce2-8d82-65094dcecaec"
 authors = ["SciML"]
-version = "2.6.1"
+version = "2.7.0"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
diff --git a/src/default.jl b/src/default.jl
index 178d72f1c..8c11c6bbf 100644
--- a/src/default.jl
+++ b/src/default.jl
@@ -268,12 +268,21 @@ end
 
 ## Defaults
 
-function SciMLBase.__init(prob::NonlinearProblem{uType, iip}, alg::Nothing, args...;
-        kwargs...) where {uType, iip}
-    SciMLBase.__init(prob, FastShortcutNonlinearPolyalg(), args...; kwargs...)
+function SciMLBase.__init(prob::NonlinearProblem, ::Nothing, args...; kwargs...)
+    return SciMLBase.__init(prob, FastShortcutNonlinearPolyalg(), args...; kwargs...)
 end
 
-function SciMLBase.__solve(prob::NonlinearProblem{uType, iip}, alg::Nothing, args...;
-        kwargs...) where {uType, iip}
-    SciMLBase.__solve(prob, FastShortcutNonlinearPolyalg(), args...; kwargs...)
+function SciMLBase.__solve(prob::NonlinearProblem, ::Nothing, args...; kwargs...)
+    return SciMLBase.__solve(prob, FastShortcutNonlinearPolyalg(), args...; kwargs...)
+end
+
+# FIXME: We default to using LM currently. But once we have line searches for GN implemented
+#        we should default to a polyalgorithm.
+function SciMLBase.__init(prob::NonlinearLeastSquaresProblem, ::Nothing, args...; kwargs...)
+    return SciMLBase.__init(prob, LevenbergMarquardt(), args...; kwargs...)
+end
+
+function SciMLBase.__solve(prob::NonlinearLeastSquaresProblem, ::Nothing, args...;
+        kwargs...)
+    return SciMLBase.__solve(prob, LevenbergMarquardt(), args...; kwargs...)
 end
diff --git a/test/nonlinear_least_squares.jl b/test/nonlinear_least_squares.jl
index c7a02dc58..6c80fbeff 100644
--- a/test/nonlinear_least_squares.jl
+++ b/test/nonlinear_least_squares.jl
@@ -34,6 +34,7 @@ solvers = [
     LevenbergMarquardt(; linsolve = LUFactorization()),
     LeastSquaresOptimJL(:lm),
     LeastSquaresOptimJL(:dogleg),
+    nothing,
 ]
 
 for prob in nlls_problems, solver in solvers