sots-engine/tests/game_ai/test_apply_order.cpp

// The order the server applies a turn's commands in.
//
// This test cannot be written against an outcome, and saying so is half of its value. Both
// captures the campaign holds put every non-empty list on ONE player and every command on ONE
// system, so any permutation of the thirty steps produces the same save and the same counter.
// The order is implemented because a later workload will need it, and the checks below are
// therefore checks against the ORIGINAL'S INSTRUCTION STREAM, not against a result:
//
//   * the six appliers the batch inlines each write the counter in place, so a watchpoint run
//     recovered their addresses; those addresses must increase in the same order as the steps
//     they belong to. That is nine of thirty positions independently pinned, and the test says
//     nine rather than pretending to thirty;
//   * the permutation must be a bijection of 1..27 and the gates must appear exactly once each,
//     which catches a transcription slip and nothing else;
//   * NEITHER the list sequence NOR the member-offset sequence may be ascending. A port that
//     loops `for (list = 1..27)`, or walks the block's members in memory order, is the obvious
//     wrong implementation and is the one thing an outcome-free test CAN rule out.
#include "game/ai/apply_order.h"

#include <cstdio>
#include <string>

using namespace sots::ai;

namespace {

int g_checks = 0;
int g_fails = 0;

void check(bool ok, const std::string& what) {
    ++g_checks;
    if (!ok) {
        ++g_fails;
        std::fprintf(stderr, "FAIL: %s\n", what.c_str());
    }
}

// Every list exactly once, every gate exactly once, and nothing else in the schedule.
void TestSchedulePartitionsTheBlock() {
    int listSeen[kCommandListCount + 1] = {};
    int gateSeen[kPrologueGateCount] = {};
    int listSteps = 0, gateSteps = 0;
    for (int i = 0; i < kApplyStepCount; ++i) {
        const ApplyStep& s = kApplySchedule[i];
        if (s.kind == ApplyStepKind::List) {
            ++listSteps;
            check(s.list >= 1 && s.list <= kCommandListCount, "list number in range");
            if (s.list >= 1 && s.list <= kCommandListCount) ++listSeen[s.list];
        } else {
            ++gateSteps;
            check(s.gateCount >= 1 && s.gateCount <= kMaxGatesPerStep, "gate count in range");
            for (int g = 0; g < s.gateCount; ++g) ++gateSeen[static_cast<int>(s.gates[g])];
        }
    }
    check(listSteps == kCommandListCount, "twenty-seven list steps");
    check(gateSteps == 3, "three gate loops");
    for (int n = 1; n <= kCommandListCount; ++n)
        check(listSeen[n] == 1, "list " + std::to_string(n) + " appears exactly once");
    // Five of the six gates have a located applier in this routine; the civilian-ratios gate has
    // none at all, and its ABSENCE from the schedule is the honest representation of that. A
    // schedule that quietly included it would be claiming a cost of zero for something whose cost
    // is unknown.
    for (int g = 0; g < kPrologueGateCount; ++g) {
        const bool located = static_cast<PrologueGate>(g) != PrologueGate::CivilianRatios;
        check(gateSeen[g] == (located ? 1 : 0),
              "gate " + std::to_string(g) + (located ? " applied once" : " has no applier here"));
    }
}

// The two orderings a wrong implementation would produce.
void TestScheduleIsNeitherSortedOrder() {
    bool listAscending = true, offsetAscending = true;
    int prevList = 0, prevOffset = 0;
    for (int i = 0; i < kApplyStepCount; ++i) {
        const ApplyStep& s = kApplySchedule[i];
        if (s.kind != ApplyStepKind::List) continue;
        if (s.list < prevList) listAscending = false;
        if (s.memberOffset < prevOffset) offsetAscending = false;
        prevList = s.list;
        prevOffset = s.memberOffset;
    }
    check(!listAscending, "the list sequence is NOT 1..27");
    check(!offsetAscending, "the member-offset sequence is NOT ascending either");
    // The two anchors a reader can check by eye against the published table.
    check(kApplySchedule[0].kind == ApplyStepKind::List && kApplySchedule[0].list == 6,
          "the batch starts at list 6");
    check(kApplySchedule[kApplyStepCount - 1].kind == ApplyStepKind::GateLoop,
          "the batch ends on a gate loop");
    check(StepIndexOfList(14) == 20, "list 14 is the twenty-first step");
    check(StepIndexOfList(8) == 24, "list 8 is the twenty-fifth step");
    check(StepIndexOfList(-1) == -1 && StepIndexOfList(28) == -1, "a bad list number has no step");
}

// The one part of the sequence this module can re-derive rather than inherit.
void TestInlinedBumpAddressesIncreaseWithTheSchedule() {
    unsigned prevAddr = 0;
    int prevStep = -1;
    for (int i = 0; i < kScheduleAnchorCount; ++i) {
        const ScheduleAnchor& a = kScheduleAnchors[i];
        check(a.address > prevAddr, std::string("address increases at ") + a.what);
        check(a.step >= prevStep, std::string("step does not go backwards at ") + a.what);
        check(a.step >= 0 && a.step < kApplyStepCount, std::string("step in range at ") + a.what);
        prevAddr = a.address;
        prevStep = a.step;
    }
    // Every anchored step must be the kind the anchor claims: the four inlined LIST appliers sit
    // on list steps and the gate-loop anchors sit on gate steps. This is what would catch an
    // anchor that had been renumbered against a reordered schedule.
    check(kApplySchedule[18].kind == ApplyStepKind::List && kApplySchedule[18].list == 12,
          "anchor 0x008902fe is list 12");
    check(kApplySchedule[19].kind == ApplyStepKind::List && kApplySchedule[19].list == 13,
          "anchor 0x008903b9 is list 13");
    check(kApplySchedule[20].kind == ApplyStepKind::List && kApplySchedule[20].list == 14,
          "anchor 0x0089046c is list 14");
    check(kApplySchedule[23].kind == ApplyStepKind::List && kApplySchedule[23].list == 7,
          "anchor 0x008905c8 is list 7");
    check(kApplySchedule[9].kind == ApplyStepKind::GateLoop, "anchor 0x0088fdb0 is gate loop A");
    check(kApplySchedule[28].kind == ApplyStepKind::GateLoop, "anchor 0x008907b1 is gate loop B");
    check(kApplySchedule[29].kind == ApplyStepKind::GateLoop, "anchor 0x0089080a is gate loop C");
}

// The gates are not one group, and the two that sit in the middle are the two research ones.
void TestGatesAreSplitAcrossTheRun() {
    const ApplyStep& a = kApplySchedule[9];
    check(a.kind == ApplyStepKind::GateLoop && a.gateCount == 3, "gate loop A tests three gates");
    check(a.gates[0] == PrologueGate::Group5 && a.gates[1] == PrologueGate::ResearchTarget &&
              a.gates[2] == PrologueGate::ResearchRate,
          "gate loop A order: group5, target, rate");
    check(kApplySchedule[28].gates[0] == PrologueGate::ResearchBoost, "gate loop B is the boost");
    check(kApplySchedule[29].gates[0] == PrologueGate::Group4, "gate loop C is group 4");
    // Nine list steps run before any gate is tested, and eighteen run after.
    int before = 0;
    for (int i = 0; i < 9; ++i) before += kApplySchedule[i].kind == ApplyStepKind::List ? 1 : 0;
    check(before == 9, "nine lists are applied before the first gate is even read");
}

// The cost half of the schedule, restated from the step rather than from the list number, so a
// step whose `bumps` flag disagreed with the 1..16 rule would be caught here.
void TestStepCostMatchesTheListCostRule() {
    for (int i = 0; i < kApplyStepCount; ++i) {
        const ApplyStep& s = kApplySchedule[i];
        if (s.kind != ApplyStepKind::List) continue;
        check(s.bumps == ListAdvancesModCount(static_cast<CommandList>(s.list)),
              "step cost agrees with the list cost rule for list " + std::to_string(s.list));
    }
}

}  // namespace

int main() {
    TestSchedulePartitionsTheBlock();
    TestScheduleIsNeitherSortedOrder();
    TestInlinedBumpAddressesIncreaseWithTheSchedule();
    TestGatesAreSplitAcrossTheRun();
    TestStepCostMatchesTheListCostRule();
    std::printf("game_ai/apply_order: %d checks, %d failures\n", g_checks, g_fails);
    return g_fails == 0 ? 0 : 1;
}