#include <catch.hpp>
#include <leatherman/execution/execution.hpp>
#include <leatherman/util/scope_exit.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/nowide/fstream.hpp>
#include <leatherman/util/regex.hpp>
#include <leatherman/util/strings.hpp>
#include <leatherman/util/scoped_env.hpp>
#include "../fixtures.hpp"
#include "../log_capture.hpp"
#include "../lth_cat.hpp"
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>

using namespace std;
using namespace leatherman::logging;
using namespace leatherman::execution::testing;
using namespace leatherman::util;
using namespace leatherman::execution;
namespace fs = boost::filesystem;

SCENARIO("searching for programs with execution::which") {
    GIVEN("an absolute path to an executable file") {
        THEN("the same path should be returned") {
            REQUIRE(
                which(EXEC_TESTS_DIRECTORY "/fixtures/facts") ==
                EXEC_TESTS_DIRECTORY "/fixtures/facts"
            );
        }
    }
    GIVEN("an absolute path to a non-executable file") {
        THEN("an empty string should be returned") {
            REQUIRE(
                which(EXEC_TESTS_DIRECTORY "/fixtures/not_executable") ==
                ""
            );
        }
    }
    GIVEN("an absolute path to a non-existant file") {
        THEN("an empty string should be returned") {
            REQUIRE(
                which(EXEC_TESTS_DIRECTORY "/fixtures/does_not_exist") ==
                ""
            );
        }
    }
    GIVEN("an executable file on the PATH") {
        THEN("the full path should be returned") {
            REQUIRE(
                which("facts", { EXEC_TESTS_DIRECTORY "/fixtures/" }) ==
                EXEC_TESTS_DIRECTORY "/fixtures/facts"
            );
        }
    }
    GIVEN("a path relative to a directory on PATH") {
        THEN("the full path should be returned") {
            REQUIRE(
                which("facts", { EXEC_TESTS_DIRECTORY "/fixtures" }) ==
                EXEC_TESTS_DIRECTORY "/fixtures/facts"
            );
        }
    }
    GIVEN("a file that does not exist on PATH") {
        THEN("an empty string should be returned") {
            REQUIRE(
                which("not_on_the_path") ==
                ""
            );
        }
    }
    GIVEN("a file that is not executable") {
        THEN("an empty string should be returned") {
            REQUIRE(
                which("not_executable", { EXEC_TESTS_DIRECTORY "/fixtures" }) ==
                ""
            );
        }
    }
}

SCENARIO("expanding command paths with execution::expand_command") {
    GIVEN("an executable on the PATH") {
        THEN("the executable is expanded to an absolute path") {
            REQUIRE(
                expand_command("facts 1 2 3", { EXEC_TESTS_DIRECTORY "/fixtures" }) ==
                EXEC_TESTS_DIRECTORY "/fixtures/facts 1 2 3"
            );
        }
    }
    GIVEN("a single-quoted command") {
        THEN("the expanded path should be single-quoted") {
            REQUIRE(
                expand_command("'facts' 1 2 3", { EXEC_TESTS_DIRECTORY "/fixtures" }) ==
                "'" EXEC_TESTS_DIRECTORY "/fixtures/facts' 1 2 3"
            );
        }
    }
    GIVEN("a double-quoted command") {
        THEN("the expanded path should be double-quoted") {
            REQUIRE(
                expand_command("\"facts\" 1 2 3", { EXEC_TESTS_DIRECTORY "/fixtures" }) ==
                "\"" EXEC_TESTS_DIRECTORY "/fixtures/facts\" 1 2 3"
            );
        }
    }
    GIVEN("a command not on PATH") {
        THEN("the returned command is empty") {
            REQUIRE(expand_command("not_on_the_path") == "");
        }
    }
    GIVEN("a non-executable command on PATH") {
        THEN("the returned command is empty") {
            REQUIRE(expand_command("not_executable", { EXEC_TESTS_DIRECTORY "/fixtures" }) == "");
        }
    }
}

SCENARIO("executing commands with execution::execute") {
    auto get_variables = [](string const& input) {
        map<string, string> variables;
        leatherman::util::each_line(input, [&](string& line) {
            vector<string> parts;
            boost::split(parts, line, boost::is_any_of("="), boost::token_compress_off);
            if (parts.size() != 2) {
                return true;
            }
            variables.emplace(make_pair(move(parts[0]), move(parts[1])));
            return true;
        });
        return variables;
    };
    std::string spool_dir { EXEC_TESTS_DIRECTORY "/spool" };
    auto get_file_content = [spool_dir](string const& filename) {
        string filepath((fs::path(spool_dir) / filename).string());
        boost::nowide::ifstream strm(filepath.c_str());
        if (!strm) FAIL("failed to open file: " + filename);
        string content((istreambuf_iterator<char>(strm)), (istreambuf_iterator<char>()));
        strm.close();
        return content;
    };
    if (!fs::exists(spool_dir) && !fs::create_directories(spool_dir)) {
        FAIL("failed to create spool directory");
    }
    scope_exit spool_cleaner([spool_dir]() { fs::remove_all(spool_dir); });
    GIVEN("a command that succeeds") {
        THEN("the output should be returned") {
            auto exec = execute("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file3.txt" });
            REQUIRE(exec.success);
            REQUIRE(exec.output == "file3");
            REQUIRE(exec.exit_code == 0);
        }
        WHEN("requested to merge the environment") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            auto exec = execute("env", {}, { {"TEST_VARIABLE1", "TEST_VALUE1" }, {"TEST_VARIABLE2", "TEST_VALUE2" } });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            THEN("the child environment should contain the given variables") {
                REQUIRE(variables.size() > 4);
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
            }
            THEN("the child environment should have LC_ALL and LANG set to C") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "C");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "C");
            }
        }
        WHEN("requested to override the environment") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            auto exec = execute("env", {}, { {"TEST_VARIABLE1", "TEST_VALUE1" }, {"TEST_VARIABLE2", "TEST_VALUE2" }}, 0, { execution_options::trim_output });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            THEN("the child environment should only contain the given variables") {
                REQUIRE(variables.size() == 4u);
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
            }
            THEN("the child environment should have LC_ALL and LANG set to C") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "C");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "C");
            }
        }
        WHEN("requested to override LC_ALL or LANG") {
            auto exec = execute("env", {}, { {"LANG", "FOO" }, { "LC_ALL", "BAR" } });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            THEN("the values should be passed to the child process") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "BAR");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "FOO");
            }
        }
        WHEN("requested to inherit locale") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            scoped_env lc_all("LC_ALL", "en_US.UTF-8");
            scoped_env lang("LANG", "en_US.UTF-8");
            auto exec = execute("env", 0, { execution_options::inherit_locale, execution_options::trim_output });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            THEN("the child environment should only have LC_ALL and LANG set to en_US.UTF-8") {
                REQUIRE(variables.size() == 2u);
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "en_US.UTF-8");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "en_US.UTF-8");
            }
        }
        WHEN("requested to inherit locale with no locale set") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            scoped_env lc_all("LC_ALL");
            scoped_env lang("LANG");
            auto exec = execute("env", 0, { execution_options::inherit_locale, execution_options::trim_output });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            CAPTURE(exec.output);
            THEN("the child environment should not have LC_ALL and LANG set") {
                REQUIRE(variables.empty());
            }
        }
        WHEN("requested to inherit locale with parent environment") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            scoped_env lc_all("LC_ALL", "en_US.UTF-8");
            scoped_env lang("LANG", "en_US.UTF-8");
            auto exec = execute("env", 0, { execution_options::inherit_locale,
                execution_options::trim_output, execution_options::merge_environment });
            REQUIRE(exec.success);
            REQUIRE(exec.exit_code == 0);
            auto variables = get_variables(exec.output);
            THEN("the child environment should contain the merged variables") {
                REQUIRE(variables.size() > 3u);
                REQUIRE(variables.count("TEST_INHERITED_VARIABLE") == 1);
                REQUIRE(variables["TEST_INHERITED_VARIABLE"] == "TEST_INHERITED_VALUE");
            }
            THEN("the child environment should have LC_ALL and LANG set to en_US.UTF-8") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "en_US.UTF-8");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "en_US.UTF-8");
            }
        }
        WHEN("expecting input") {
            auto exec = execute("cat", {}, "hello");
            REQUIRE(exec.success);
            REQUIRE(exec.output == "hello");
            REQUIRE(exec.error == "");
            REQUIRE(exec.exit_code == 0);
        }
        WHEN("expecting input with lots of output") {
            auto exec = execute(CMAKE_BIN_DIRECTORY "/lth_cat", { "prefix", "suffix", "overwhelm", "stderr" },
                "hello\ngoodbye", 0, { execution_options::merge_environment });
            REQUIRE(exec.success);
            REQUIRE(exec.output == lth_cat::prefix+lth_cat::overwhelm+"hello\n"+lth_cat::overwhelm+"goodbye\n"+lth_cat::overwhelm+lth_cat::suffix);
            REQUIRE(exec.error == "hello\ngoodbye\n");
            REQUIRE(exec.exit_code == 0);
        }
        WHEN("requested to write stdout to file") {
            string out_file(spool_dir + "/stdout_test.out");
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message", {}, "", out_file);
            REQUIRE(fs::exists(out_file));
            THEN("stdout is correctly redirected to file") {
                auto output = get_file_content("stdout_test.out");
                REQUIRE(output == "foo=bar\nsome more stuff\n");
            }
            THEN("the returned results are correct and stdout was not buffered") {
                REQUIRE(exec.success);
                REQUIRE(exec.output.empty());
                REQUIRE(exec.error == "error message!");
            }
        }
        WHEN("requested to write stdout and stderr to the same file with trim") {
            string out_file(spool_dir + "/stdout_stderr_test.out");
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message", {}, "", out_file, "", map<string, string>(), nullptr, 0, { execution_options::trim_output, execution_options::merge_environment, execution_options::redirect_stderr_to_stdout });
            REQUIRE(fs::exists(out_file));
            THEN("stdout and stderr are correctly redirected to file") {
                auto output = get_file_content("stdout_stderr_test.out");
                REQUIRE(output == "error message!\nfoo=bar\nsome more stuff\n");
            }
            THEN("the returned results are correct and out/err streams were not buffered") {
                REQUIRE(exec.success);
                REQUIRE(exec.output.empty());
                REQUIRE(exec.error.empty());
            }
        }
        WHEN("requested to write stdout to a file in an unknown directory") {
            bool success = false;
            try {
                execute("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file1.txt" }, "", EXEC_TESTS_DIRECTORY "/spam/eggs/stdout.out");
                success = true;
            } catch (...) {
                // pass
            }
            THEN("it fails") {
                REQUIRE_FALSE(success);
            }
        }
        WHEN("requested to write both stdout and stderr to file with permissions") {
            string out_file(spool_dir + "/stdout_test_b.out");
            string err_file(spool_dir + "/stderr_test_b.err");
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message", {}, "", out_file, err_file, {}, nullptr, 0,
                                fs::owner_read | fs::owner_write | fs::group_read, lth_util::option_set<execution_options>{});
            REQUIRE(fs::exists(out_file));
            REQUIRE(fs::exists(err_file));
            THEN("stdout and stderr are correctly redirected to different files") {
                auto output = get_file_content("stdout_test_b.out");
                auto error = get_file_content("stderr_test_b.err");
                REQUIRE(output == "foo=bar\n\nsome more stuff\n");
                REQUIRE(error == "error message!\n");
            }
            THEN("the files have restricted permissions") {
                auto out_perms = fs::status(out_file).permissions();
                auto err_perms = fs::status(err_file).permissions();
                REQUIRE(out_perms == (fs::owner_read | fs::owner_write | fs::group_read));
                REQUIRE(err_perms == (fs::owner_read | fs::owner_write | fs::group_read));
            }
            THEN("the returned results are correct and out/err streams were not buffered") {
                REQUIRE(exec.success);
                REQUIRE(exec.output.empty());
                REQUIRE(exec.error.empty());
            }
        }
        WHEN("requested to write both stdout and stderr to file without trim") {
            string out_file(spool_dir + "/stdout_test_b.out");
            string err_file(spool_dir + "/stderr_test_b.err");
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message", {}, "",
                                out_file, err_file, {}, nullptr, 0, lth_util::option_set<execution_options>{});
            REQUIRE(fs::exists(out_file));
            REQUIRE(fs::exists(err_file));
            THEN("stdout and stderr are correctly redirected to different files") {
                auto output = get_file_content("stdout_test_b.out");
                auto error = get_file_content("stderr_test_b.err");
                REQUIRE(output == "foo=bar\n\nsome more stuff\n");
                REQUIRE(error == "error message!\n");
            }
            THEN("the returned results are correct and out/err streams were not buffered") {
                REQUIRE(exec.success);
                REQUIRE(exec.output.empty());
                REQUIRE(exec.error.empty());
            }
        }
        WHEN("requested to write stderr to a file in a directory that does not exist") {
            string out_file(spool_dir + "/good.out");
            string err_file(spool_dir + "/spam/eggs/bad.err");
            bool success = false;
            try {
                execute("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file1.txt" }, "", out_file, err_file);
                success = true;
            } catch (...) {
                // pass
            }
            THEN("it fails") {
                REQUIRE_FALSE(success);
            }
        }
        WHEN("requested to execute a PID callback") {
            int pid_from_callback;
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/echo_pid", {}, "", map<string,string>(), [&pid_from_callback](size_t pid) { pid_from_callback = pid; });
            THEN("the returned results are correct") {
                REQUIRE(exec.success);
                REQUIRE_FALSE(exec.output.empty());
                REQUIRE(exec.error.empty());
            }
            THEN("the callback is successfully executed") {
                REQUIRE(to_string(pid_from_callback) == exec.output);
            }
        }
    }
    GIVEN("a command that fails") {
        WHEN("default options are used") {
            auto exec = execute("ls", { "does_not_exist" });
            THEN("no output is returned") {
                REQUIRE_FALSE(exec.success);
                REQUIRE(exec.output == "");
                REQUIRE(exec.error == "");
                REQUIRE(exec.exit_code > 0);
            }
        }
        WHEN("the redirect stderr option is used") {
            auto exec = execute("ls", { "does_not_exist" }, 0, { execution_options::trim_output, execution_options::merge_environment, execution_options::redirect_stderr_to_stdout });
            THEN("error output is returned") {
                REQUIRE_FALSE(exec.success);
                REQUIRE(boost::ends_with(exec.output, "No such file or directory"));
                REQUIRE(exec.error == "");
                REQUIRE(exec.exit_code > 0);
            }
        }
        WHEN("not redirecting stderr to null") {
            auto exec = execute("ls", { "does_not_exist" }, 0, { execution_options::trim_output, execution_options::merge_environment });
            THEN("error output is returned") {
                REQUIRE_FALSE(exec.success);
                REQUIRE(exec.output == "");
                REQUIRE(boost::ends_with(exec.error, "No such file or directory"));
                REQUIRE(exec.exit_code > 0);
            }
        }
        WHEN("the 'throw on non-zero exit' option is used") {
            THEN("a child exit exception is thrown") {
                REQUIRE_THROWS_AS(execute("ls", {"does_not_exist"}, 0, {execution_options::trim_output, execution_options::merge_environment, execution_options::throw_on_nonzero_exit}), child_exit_exception);
            }
        }
        WHEN("the 'throw on signal' option is used") {
            THEN("a child signal exception is thrown") {
                REQUIRE_THROWS_AS(execute("sh", { EXEC_TESTS_DIRECTORY "/fixtures/execution/selfkill.sh" }, 0, { execution_options::trim_output, execution_options::merge_environment, execution_options::throw_on_signal }), child_signal_exception);
            }
        }
    }
    GIVEN("a command that outputs leading/trailing whitespace") {
        THEN("whitespace should be trimmed by default") {
            auto exec = execute("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file1.txt" });
            REQUIRE(exec.success);
            REQUIRE(exec.output == "this is a test of trimming");
        }
        WHEN("the 'trim whitespace' option is not used") {
            auto exec = execute("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file1.txt" }, 0, { execution_options::merge_environment });
            THEN("whitespace should not be trimmed") {
                REQUIRE(exec.output == "   this is a test of trimming   ");
            }
        }
    }
    GIVEN("a long-running command") {
        WHEN("given a timeout") {
            THEN("a timeout exception should be thrown") {
                try {
                    execute("sh", { EXEC_TESTS_DIRECTORY "/fixtures/execution/sleep.sh" }, 1);
                    FAIL("did not throw timeout exception");
                } catch (timeout_exception const& ex) {
                    // Verify the process group was killed by waiting for it
                    int status = 0;
                    REQUIRE(waitpid(-ex.pid(), &status, WNOHANG) == -1);
                    REQUIRE(errno == ECHILD);
                } catch (exception const&) {
                    FAIL("unexpected exception thrown");
                }
            }
        }
    }
    GIVEN("stderr is redirected to null") {
        WHEN("using a debug log level") {
            log_capture capture(log_level::debug);
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message");
            REQUIRE(exec.success);
            REQUIRE(exec.output == "foo=bar\n\nsome more stuff");
            REQUIRE(exec.error.empty());
            THEN("stderr is logged") {
                auto output = capture.result();
                CAPTURE(output);
                REQUIRE(re_search(output, boost::regex("DEBUG !!! - error message!")));
            }
        }
        WHEN("not using a debug log level") {
            log_capture capture(log_level::warning);
            auto exec = execute(EXEC_TESTS_DIRECTORY "/fixtures/error_message");
            REQUIRE(exec.success);
            REQUIRE(exec.output == "foo=bar\n\nsome more stuff");
            REQUIRE(exec.error.empty());
            THEN("stderr is not logged") {
                auto output = capture.result();
                CAPTURE(output);
                REQUIRE_FALSE(re_search(output, boost::regex("DEBUG !!! - error message!")));
            }
        }
    }
}

SCENARIO("executing commands with execution::each_line") {
    GIVEN("a command that succeeds") {
        THEN("each line of output should be returned") {
            vector<string> lines;
            bool success = each_line("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file4.txt" }, [&](string& line) {
                lines.push_back(line);
                return true;
            });
            REQUIRE(success);
            REQUIRE(lines.size() == 4u);
            REQUIRE(lines[0] == "line1");
            REQUIRE(lines[1] == "line2");
            REQUIRE(lines[2] == "line3");
            REQUIRE(lines[3] == "line4");
        }
        WHEN("output stops when false is returned from callback") {
            vector<string> lines;
            bool success = each_line("cat", { EXEC_TESTS_DIRECTORY "/fixtures/ls/file4.txt" }, [&](string& line) {
                lines.push_back(line);
                return false;
            });
            REQUIRE(success);
            REQUIRE(lines.size() == 1u);
            REQUIRE(lines[0] == "line1");
        }
        WHEN("requested to merge the environment") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            map<string, string> variables;
            bool success = each_line("env", {}, { {"TEST_VARIABLE1", "TEST_VALUE1" }, {"TEST_VARIABLE2", "TEST_VALUE2" } }, [&](string& line) {
                vector<string> parts;
                boost::split(parts, line, boost::is_any_of("="), boost::token_compress_off);
                if (parts.size() != 2) {
                    return true;
                }
                variables.emplace(make_pair(move(parts[0]), move(parts[1])));
                return true;
            });
            REQUIRE(success);
            THEN("the child environment should contain the given variables") {
                REQUIRE(variables.size() > 4);
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
            }
            THEN("the child environment should have LC_ALL and LANG set to C") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "C");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "C");
            }
        }
        WHEN("requested to override the environment") {
            scoped_env test_var("TEST_INHERITED_VARIABLE", "TEST_INHERITED_VALUE");
            map<string, string> variables;
            bool success = each_line(
                "env",
                {},
                {
                    {"TEST_VARIABLE1", "TEST_VALUE1" },
                    {"TEST_VARIABLE2", "TEST_VALUE2" }
                },
                [&](string& line) {
                    vector<string> parts;
                    boost::split(parts, line, boost::is_any_of("="), boost::token_compress_off);
                    if (parts.size() != 2) {
                        return true;
                    }
                    variables.emplace(make_pair(move(parts[0]), move(parts[1])));
                    return true;
                },
                nullptr,
                0,
                {
                    execution_options::trim_output
                });
            REQUIRE(success);
            THEN("the child environment should only contain the given variables") {
                REQUIRE(variables.size() == 4u);
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
                REQUIRE(variables.count("TEST_VARIABLE1") == 1);
                REQUIRE(variables["TEST_VARIABLE1"] == "TEST_VALUE1");
            }
            THEN("the child environment should have LC_ALL and LANG set to C") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "C");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "C");
            }
        }
        WHEN("requested to override LC_ALL or LANG") {
            map<string, string> variables;
            bool success = each_line("env", {}, { {"LANG", "FOO" }, { "LC_ALL", "BAR" } }, [&](string& line) {
                vector<string> parts;
                boost::split(parts, line, boost::is_any_of("="), boost::token_compress_off);
                if (parts.size() != 2) {
                    return true;
                }
                variables.emplace(make_pair(move(parts[0]), move(parts[1])));
                return true;
            });
            REQUIRE(success);
            THEN("the values should be passed to the child process") {
                REQUIRE(variables.count("LC_ALL") == 1);
                REQUIRE(variables["LC_ALL"] == "BAR");
                REQUIRE(variables.count("LANG") == 1);
                REQUIRE(variables["LANG"] == "FOO");
            }
        }
    }
    GIVEN("a command that fails") {
        WHEN("default options are used") {
            THEN("no output is returned") {
                auto success = each_line("ls", { "does_not_exist" }, [](string& line) {
                    FAIL("should not be called");
                    return true;
                });
                REQUIRE_FALSE(success);
            }
        }
        WHEN("the redirect stderr option is used") {
            string output;
            auto result = each_line(
                "ls",
                {
                    "does_not_exist"
                },
                [&](string& line) {
                    if (!output.empty()) {
                        output += "\n";
                    }
                    output += line;
                    return true;
                },
                nullptr,
                0,
                {
                    execution_options::trim_output,
                    execution_options::merge_environment,
                    execution_options::redirect_stderr_to_stdout
                });
            THEN("error output is returned") {
                REQUIRE_FALSE(result);
                REQUIRE(boost::ends_with(output, "No such file or directory"));
            }
        }
        WHEN("not redirecting stderr to null") {
            string output;
            string error;
            auto result = each_line(
                "ls",
                {
                    "does_not_exist"
                },
                [&](string& line) {
                    if (!output.empty()) {
                        output += "\n";
                    }
                    output += line;
                    return true;
                },
                [&](string& line) {
                    if (!error.empty()) {
                        error += "\n";
                    }
                    error += line;
                    return true;
                });
            THEN("error output is returned") {
                REQUIRE_FALSE(result);
                REQUIRE(output == "");
                REQUIRE(boost::ends_with(error, "No such file or directory"));
            }
        }
        WHEN("redirecting stderr to null") {
            string error;
            auto result = each_line(
                "ls",
                {
                    "does_not_exist"
                },
                nullptr,
                [&](string& line) {
                    if (!error.empty()) {
                        error += "\n";
                    }
                    error += line;
                    return true;
                },
                0,
                {
                    execution_options::trim_output,
                    execution_options::merge_environment,
                    execution_options::redirect_stderr_to_null
                });
            THEN("no error output is returned") {
                REQUIRE_FALSE(result);
                REQUIRE(error == "");
            }
        }
        WHEN("the 'throw on non-zero exit' option is used") {
            THEN("a child exit exception is thrown") {
                REQUIRE_THROWS_AS(each_line("ls", {"does_not_exist"}, nullptr, nullptr, 0, {execution_options::trim_output, execution_options::merge_environment, execution_options::throw_on_nonzero_exit}), child_exit_exception);
            }
        }
        WHEN("the 'throw on signal' option is used") {
            THEN("a child signal exception is thrown") {
                REQUIRE_THROWS_AS(each_line("sh", { EXEC_TESTS_DIRECTORY "/fixtures/execution/selfkill.sh" }, nullptr, nullptr, 0, { execution_options::trim_output, execution_options::merge_environment, execution_options::throw_on_signal }), child_signal_exception);
            }
        }
    }
    GIVEN("a long-running command") {
        WHEN("given a timeout") {
            THEN("a timeout exception should be thrown") {
                try {
                    each_line("sh", { EXEC_TESTS_DIRECTORY "/fixtures/execution/sleep.sh" }, nullptr, nullptr, 1);
                    FAIL("did not throw timeout exception");
                } catch (timeout_exception const& ex) {
                    // Verify the process group was killed by waiting for it
                    int status = 0;
                    REQUIRE(waitpid(-ex.pid(), &status, WNOHANG) == -1);
                    REQUIRE(errno == ECHILD);
                } catch (exception const&) {
                    FAIL("unexpected exception thrown");
                }
            }
        }
    }
    GIVEN("stderr is redirected to null") {
        WHEN("using a debug log level") {
            log_capture capture(log_level::debug);
            REQUIRE(leatherman::execution::each_line(EXEC_TESTS_DIRECTORY "/fixtures/error_message", nullptr));
            THEN("stderr is logged") {
                auto output = capture.result();
                CAPTURE(output);
                REQUIRE(re_search(output, boost::regex("DEBUG !!! - error message!")));
            }
        }
        WHEN("not using a debug log level") {
            log_capture capture(log_level::warning);
            REQUIRE(leatherman::execution::each_line(EXEC_TESTS_DIRECTORY "/fixtures/error_message", nullptr));
            THEN("stderr is not logged") {
                auto output = capture.result();
                CAPTURE(output);
                REQUIRE_FALSE(re_search(output, boost::regex("DEBUG !!! - error message!")));
            }
        }
    }
}