Add item bank funcs to stateful + interface test

Author: Frankie Robertson

ext/TestExt.jl

@@ -2,8 +2,9 @@ module TestExt
 
 using Test
 using ComputerAdaptiveTesting: Stateful
+using FittedItemBanks: AbstractItemBank, ItemResponse, resp
 
-export test_stateful_cat_1d_dich_ib
+export test_stateful_cat_1d_dich_ib, test_stateful_cat_item_bank_1d_dich_ib
 
 function test_stateful_cat_1d_dich_ib(
         cat::Stateful.StatefulCat,
@@ -66,9 +67,8 @@ function test_stateful_cat_1d_dich_ib(
         end
     end
 
-    Stateful.reset!(cat)
-
     @testset "basic get_ability tests" begin
+        Stateful.reset!(cat)
         Stateful.add_response!(cat, 1, false)
         Stateful.add_response!(cat, 2, true)
         ability = Stateful.get_ability(cat)
@@ -79,6 +79,7 @@ function test_stateful_cat_1d_dich_ib(
 
     if supports_rollback
         @testset "rollback ability tests" begin
+            Stateful.reset!(cat)
             Stateful.add_response!(cat, 1, false)
             ability1 = Stateful.get_ability(cat)
             Stateful.add_response!(cat, 2, true)
@@ -91,4 +92,22 @@ function test_stateful_cat_1d_dich_ib(
     end
 end
 
+function test_stateful_cat_item_bank_1d_dich_ib(
+    cat::Stateful.StatefulCat,
+    item_bank::AbstractItemBank,
+    points=[-.78, 0.0, .78],
+    margin=0.05,
+)
+    if length(item_bank) != Stateful.item_bank_size(cat)
+        error("Item bank length does not match the cat's item bank size.")
+    end
+    for i in 1:length(item_bank)
+        for point in points
+            cat_prob = Stateful.item_response_function(cat, i, true, point)
+            ib_prob = resp(ItemResponse(item_bank, i), true, point)
+            @test cat_prob ≈ ib_prob  rtol=margin
+        end
+    end
+end
+
 end

src/Stateful.jl

@@ -7,7 +7,7 @@ module Stateful
 
 using DocStringExtensions
 
-using FittedItemBanks: AbstractItemBank, ResponseType
+using FittedItemBanks: AbstractItemBank, ResponseType, ItemResponse, resp
 using ..Aggregators: TrackedResponses, Aggregators
 using ..CatConfig: CatLoopConfig, CatRules
 using ..Responses: BareResponses, Response, Responses
@@ -124,6 +124,25 @@ but should attempt to interoperate with ComputerAdaptiveTesting.jl.
 """
 function get_ability end
 
+"""
+```julia
+$(FUNCTIONNAME)(config::StatefulCat)
+````
+
+Return number of items in the current item bank.
+"""
+function item_bank_size end
+
+"""
+```julia
+$(FUNCTIONNAME)(config::StatefulCat, index::IndexT, response::ResponseT, ability::AbilityT) -> Float
+````
+
+Return the probability of a `response` to item at `index` for someone with
+a certain `ability` according to the IRT model backing the CAT.
+"""
+function item_response_function end
+
 ## Running the CAT
 function Sim.run_cat(cat_config::CatLoopConfig{RulesT},
         ib_labels = nothing) where {RulesT <: StatefulCat}
@@ -220,6 +239,16 @@ function get_ability(config::StatefulCatConfig)
     return (config.rules.ability_estimator(config.tracked_responses[]), nothing)
 end
 
+function item_bank_size(config::StatefulCatConfig)
+    return length(config.tracked_responses[].item_bank)
+end
+
+function item_response_function(config::StatefulCatConfig, index, response, ability)
+    item_bank = config.tracked_responses[].item_bank
+    item_response = ItemResponse(item_bank, index)
+    return resp(item_response, response, ability)
+end
+
 ## TODO: Implementation for MaterializedDecisionTree
 
 end

test/stateful.jl

@@ -88,5 +88,6 @@
             4;
             supports_ranked_and_criteria = false,
         )
+        TestExt.test_stateful_cat_item_bank_1d_dich_ib(cat_config, item_bank)
     end
 end