add iteration test

Author: lkdvos

test/logging.jl

@@ -0,0 +1,57 @@
+using Test
+using AlgorithmsInterface
+
+# Dummy types for a minimal iterative algorithm
+struct LogDummyProblem <: Problem end
+struct LogDummyAlgorithm <: Algorithm
+    stopping_criterion
+end
+mutable struct LogDummyState{S <: StoppingCriterionState} <: State
+    iterate::Float64
+    iteration::Int
+    stopping_criterion_state::S
+end
+
+# State initialization for the dummy algorithm
+function AlgorithmsInterface.initialize_state(problem::LogDummyProblem, algorithm::LogDummyAlgorithm; kwargs...)
+    sc_state = initialize_state(problem, algorithm, algorithm.stopping_criterion; kwargs...)
+    return LogDummyState(0.0, 0, sc_state)
+end
+function AlgorithmsInterface.initialize_state!(
+        problem::LogDummyProblem,
+        algorithm::LogDummyAlgorithm,
+        state::LogDummyState;
+        kwargs...
+    )
+    initialize_state!(problem, algorithm, algorithm.stopping_criterion, state.stopping_criterion_state; kwargs...)
+    state.iterate = 0.0
+    state.iteration = 0
+    return state
+end
+
+# One trivial step per iteration (not relevant for the logging test)
+function AlgorithmsInterface.step!(
+        ::LogDummyProblem,
+        ::LogDummyAlgorithm,
+        state::LogDummyState,
+    )
+    state.iterate += 1.0
+    return state
+end
+
+@testset "CallbackAction logs iteration on each step" begin
+    problem = LogDummyProblem()
+    algorithm = LogDummyAlgorithm(StopAfterIteration(3))
+
+    # Action that logs the current iteration number at :PostStep
+    iter_logger = CallbackAction() do problem, algorithm, state
+        @info "Iter $(state.iteration)"
+    end
+
+    # Expect exactly three info logs for iterations 1, 2, 3
+    @test_logs (:info, "Iter 1") (:info, "Iter 2") (:info, "Iter 3") begin
+        with_algorithmlogger(:PostStep => iter_logger) do
+            solve(problem, algorithm)
+        end
+    end
+end

test/runtests.jl

@@ -12,6 +12,10 @@ end
     include("stopping_criterion.jl")
 end
 
+@safetestset "Logging Infrastructure" begin
+    include("logging.jl")
+end
+
 @safetestset "Aqua" begin
     using AlgorithmsInterface, Aqua
     Aqua.test_all(AlgorithmsInterface)