zircon/system/utest/fit/result_examples.cpp

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <string>

#include <lib/fit/result.h>
#include <unittest/unittest.h>

namespace {
namespace example1 {
fit::result<int, std::string> divide(int dividend, int divisor) {
    if (divisor == 0)
        return fit::error<std::string>("divide by zero");
    return fit::ok(dividend / divisor);
}

int try_divide(int dividend, int divisor) {
    auto result = divide(dividend, divisor);
    if (result.is_ok()) {
        printf("%d / %d = %d\n", dividend, divisor, result.value());
        return result.value();
    }
    printf("%d / %d: ERROR %s\n", dividend, divisor, result.error().c_str());
    return -999;
}

fit::result<> open(std::string secret) {
    printf("guessing \"%s\"\n", secret.c_str());
    if (secret == "sesame") {
        puts("yes!");
        return fit::ok();
    }
    puts("no.");
    return fit::error();
}

bool guess_combination() {
    return open("friend") || open("sesame") || open("I give up");
}

bool test() {
    BEGIN_TEST;

    EXPECT_EQ(2, try_divide(5, 2));
    EXPECT_EQ(-999, try_divide(5, 0));
    EXPECT_TRUE(guess_combination());

    END_TEST;
}
} // namespace example1
} // namespace

BEGIN_TEST_CASE(result_examples)
RUN_TEST(example1::test)
END_TEST_CASE(result_examples)