cpp-shared-random-generator/test/tape_test.cxx

//
//  tape_test.cpp
//  shared_random_generator-test
//
//  Created by Sam Jaffe on 3/19/23.
//  Copyright © 2023 Sam Jaffe. All rights reserved.
//

#include "random/tape.h"

#include "random/random.h"

#include "xcode_gtest_helper.h"

using testing::ElementsAre;
using testing::FieldsAre;

TEST(TapeTest, CanRecordIntData) {
  engine::random::Tape tape;
  
  tape.exclusive(100u, 50);
  EXPECT_EQ(tape.exclusive(100), 50);
}

TEST(TapeTest, CanRecordDoubleData) {
  engine::random::Tape tape;
  
  tape.exclusive(0.0, 100.0, 50.0);
  EXPECT_EQ(tape.exclusive(0.0, 100.0), 50.0);

  tape.inclusive(0.0, 100.0, 50.0);
  EXPECT_EQ(tape.inclusive(0.0, 100.0), 50.0);
}

TEST(TapeTest, ThrowsOnOverFetch) {
  engine::random::Tape tape;
  tape.exclusive(100u, 50);
  EXPECT_EQ(tape.exclusive(100), 50);
  EXPECT_THROW(tape.exclusive(100), std::out_of_range);
}

TEST(TapeTest, BadRequestIsNoOp) {
  engine::random::Tape tape;
  tape.exclusive(100u, 50);
  EXPECT_ANY_THROW(tape.exclusive(1));
  EXPECT_EQ(tape.exclusive(100), 50);
}

TEST(TapeTest, ThrowsOnTypeMismatch) {
  engine::random::Tape tape;
  tape.exclusive(100u, 50);
  EXPECT_THROW(tape.exclusive(0.0, 100.0), std::domain_error);
}

TEST(TapeTest, ThrowsOnInclusiveExclusiveMismatch) {
  engine::random::Tape tape;
  tape.exclusive(0.0, 100.0, 50.0);
  EXPECT_THROW(tape.inclusive(0.0, 100.0), std::domain_error);
}

TEST(TapeTest, ThrowsOnBoundsMismatch) {
  engine::random::Tape tape;
  tape.exclusive(0.0, 100.0, 50.0);
  EXPECT_THROW(tape.exclusive(0.0, 1.0), std::logic_error);
}

TEST(TapeTest, IsOrdered) {
  engine::random::Tape tape;
  tape.exclusive(0.0, 100.0, 50.0);
  tape.inclusive(0.0, 100.0, 50.0);
  
  EXPECT_THROW(tape.inclusive(0.0, 100.0), std::domain_error);

  EXPECT_EQ(tape.exclusive(0.0, 100.0), 50.0);
  EXPECT_EQ(tape.inclusive(0.0, 100.0), 50.0);
}

TEST(TapeTest, IsSerializable) {
  engine::random::Tape tape;
  tape.exclusive(100u, 50);
  tape.exclusive(0.0, 100.0, 50.0);
  tape.inclusive(0.0, 100.0, 50.0);
  
  auto serial = engine::random::Tape::serial_type(tape);
  EXPECT_THAT(serial, ElementsAre(FieldsAre(true, "j", 0, 100, 50),
                                  FieldsAre(true, "d", 0, 100, 50),
                                  FieldsAre(false, "d", 0, 100, 50)));
  
  tape = engine::random::Tape(serial);
  EXPECT_EQ(tape.exclusive(100), 50);
  EXPECT_EQ(tape.exclusive(0.0, 100.0), 50.0);
  EXPECT_EQ(tape.inclusive(0.0, 100.0), 50.0);
}

TEST(TapeTest, IndexNotIncludedInSerialization) {
  engine::random::Tape tape;
  tape.exclusive(100u, 50);
  tape.exclusive(0.0, 100.0, 50.0);
  tape.inclusive(0.0, 100.0, 50.0);
  
  EXPECT_EQ(tape.exclusive(100), 50);
  EXPECT_EQ(tape.exclusive(0.0, 100.0), 50.0);
  
  auto serial = engine::random::Tape::serial_type(tape);
  EXPECT_THAT(serial, ElementsAre(FieldsAre(true, "j", 0, 100, 50),
                                  FieldsAre(true, "d", 0, 100, 50),
                                  FieldsAre(false, "d", 0, 100, 50)));
  
  tape = engine::random::Tape(serial);
  EXPECT_EQ(tape.exclusive(100), 50);
  EXPECT_EQ(tape.exclusive(0.0, 100.0), 50.0);
  EXPECT_EQ(tape.inclusive(0.0, 100.0), 50.0);
}

TEST(TapeTest, CanAttachToRandom) {
  engine::random::Random random;
  auto tape = std::make_shared<engine::random::Tape>();

  auto scope = random.record(tape);
  
  auto result = random.exclusive(100);
  EXPECT_EQ(tape->exclusive(100), result);
}

TEST(TapeTest, StopsRecordingOnScopeExit) {
  engine::random::Random random;
  auto tape = std::make_shared<engine::random::Tape>();

  {
    auto scope = random.record(tape);
    random.exclusive(100);
  }
  random.exclusive(100);
  
  EXPECT_NO_THROW(tape->exclusive(100));
  EXPECT_THROW(tape->exclusive(100), std::out_of_range);
}