Add allocation tests for interface implementations

Project.toml

@@ -4,7 +4,9 @@ authors = ["Samuel Belko <samuelbelko@protonmail.com> and contributors"]
 version = "1.1.0"
 
 [compat]
+AllocCheck = "0.2"
 Aqua = "0.8"
+BenchmarkTools = "1"
 JET = "0.9, 0.10, 0.11"
 LinearAlgebra = "1.10"
 SafeTestsets = "0.1"
@@ -13,12 +15,14 @@ Test = "1.10"
 julia = "1.10"
 
 [extras]
+AllocCheck = "9b6a8646-10ed-4001-bbdc-1d2f46dfbb1a"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+BenchmarkTools = "6e4b80f9-dd63-53aa-95a3-0cdb28fa8baf"
 JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua", "JET", "LinearAlgebra", "SafeTestsets", "Statistics", "Test"]
+test = ["AllocCheck", "Aqua", "BenchmarkTools", "JET", "LinearAlgebra", "SafeTestsets", "Statistics", "Test"]

test/alloc_tests.jl

@@ -0,0 +1,54 @@
+using SurrogatesBase
+using AllocCheck
+using BenchmarkTools
+using Test
+
+# This file tests that implementations of the SurrogatesBase interface
+# can be made allocation-free when properly implemented.
+# Since SurrogatesBase is an interface-only package, we test with
+# simple concrete implementations.
+
+# Simple deterministic surrogate that returns a constant value
+struct ConstantSurrogate <: AbstractDeterministicSurrogate
+    value::Float64
+end
+
+# Allocation-free call operator
+(s::ConstantSurrogate)(::Float64) = s.value
+
+# Simple linear surrogate: f(x) = a*x + b
+struct LinearSurrogate <: AbstractDeterministicSurrogate
+    a::Float64
+    b::Float64
+end
+
+# Allocation-free call operator
+(s::LinearSurrogate)(x::Float64) = s.a * x + s.b
+
+@testset "Allocation Tests" begin
+    @testset "ConstantSurrogate allocation-free" begin
+        s = ConstantSurrogate(42.0)
+        x = 1.0
+
+        # Warmup
+        s(x)
+
+        # Use BenchmarkTools for accurate allocation measurement
+        result = @benchmark $s($x)
+        @test result.memory == 0
+        @test result.allocs == 0
+    end
+
+    @testset "LinearSurrogate allocation-free" begin
+        s = LinearSurrogate(2.0, 1.0)
+        x = 3.0
+
+        # Warmup
+        s(x)
+
+        # Use BenchmarkTools for accurate allocation measurement
+        result = @benchmark $s($x)
+        @test result.memory == 0
+        @test result.allocs == 0
+    end
+end

test/runtests.jl

@@ -117,3 +117,8 @@ end
     @test length(m) == 3
     @test m[1] ≈ parameters(ss)
 end
+
+# Allocation tests - run in nopre group to avoid precompilation interference
+if get(ENV, "GROUP", "all") == "all" || get(ENV, "GROUP", "all") == "nopre"
+    @safetestset "Allocation Tests" include("alloc_tests.jl")
+end