Add test for ForwardDiff with StaticArrays

test/forwarddiff_overloads.jl

@@ -193,3 +193,49 @@ overload_x_p = solve(prob, UMFPACKFactorization())
 backslash_x_p = A \ b
 
 @test ≈(overload_x_p, backslash_x_p, rtol = 1e-9)
+
+
+# Test StaticArrays
+# They don't go through the overloads
+# But we should test that the overloads don't mess anything up
+function static_h(p)
+    A = @SMatrix [p[1] p[2]+1 p[2]^3;
+                  3*p[1] p[1]+5 p[2] * p[1]-4;
+                  p[2]^2 9*p[1] p[2]]
+
+    b = SA[p[1] + 1, p[2] * 2, p[1]^2]
+
+    (A, b)
+end
+
+# Check to make sure it's not a DualLinearCache
+function static_linsolve_cache_check(p)
+    A,b = static_h(p)
+    prob = LinearProblem(A, b)
+    cache = init(prob)
+    cache isa LinearCache
+end
+
+@test static_linsolve_cache_check([5.0, 5.0])
+
+function static_linsolve(p)
+    A, b = static_h(p)
+    prob = LinearProblem(A, b)
+    solve(prob)
+end
+
+function static_backslash(p)
+    A, b = static_h(p)
+    A \ b
+end
+
+@test (ForwardDiff.jacobian(static_linsolve, [5.0, 5.0]) ≈
+       ForwardDiff.jacobian(static_backslash, [5.0, 5.0]))
+
+#Test to make sure that the cache is not a DualLinearCache
+A, b = static_h([ForwardDiff.Dual(5.0, 1.0, 0.0), ForwardDiff.Dual(5.0, 0.0, 1.0)])
+
+static_dual_prob = LinearProblem(A, b)
+static_dual_cache = init(static_dual_prob)
+
+@test static_dual_cache isa LinearSolve.LinearCache