fix

Author: st--

test/Project.toml

@@ -1,5 +1,6 @@
 [deps]
 AxisArrays = "39de3d68-74b9-583c-8d2d-e117c070f3a9"
+Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
 Distances = "b4f34e82-e78d-54a5-968a-f98e89d6e8f7"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"

test/basekernels/constant.jl

@@ -36,6 +36,6 @@
 
         # Standardised tests.
         TestUtils.test_interface(k, Float64)
-        test_ADs(c -> ConstantKernel(; c=first(c)), [c])
+        test_ADs(c -> ConstantKernel(; c=only(c)), [c])
     end
 end

test/basekernels/exponential.jl

@@ -56,7 +56,7 @@
         @test metric(k2) isa WeightedEuclidean
         @test k2(v1, v2) ≈ k(v1, v2)
 
-        test_ADs(γ -> GammaExponentialKernel(; gamma=first(γ)), [1 + 0.5 * rand()])
+        test_ADs(γ -> GammaExponentialKernel(; gamma=only(γ)), [1 + 0.5 * rand()])
         test_params(k, ([γ],))
         TestUtils.test_interface(GammaExponentialKernel(; γ=1.36))
 

test/runtests.jl

@@ -14,6 +14,7 @@ using Zygote: Zygote
 using ForwardDiff: ForwardDiff
 using ReverseDiff: ReverseDiff
 using FiniteDifferences: FiniteDifferences
+using Compat: only
 
 using KernelFunctions: SimpleKernel, metric, kappa, ColVecs, RowVecs, TestUtils