Replace git2::Exception with Result

[ken-matsui]

No description provided.

[adityamwagh]

If I understand correctly, this is to replace git2::Exception with a Result type defined in Rustify/Result.hpp right?

[ken-matsui]

Yes, correct

[adityamwagh]

Would something like this suffice?

static Result<std::string> getAuthor() noexcept {
  git2::Config config;
  if (auto res = config.openDefault(); !res) {
    logger::debug("Failed to open git config: {}", res.error().message());
    return Err(to_anyhow(res.error().message()));
  }

  auto name = toml::try_find<std::string>(config, "user.name");
  if (!name) {
    logger::debug("Failed to get user.name: {}", name.error().message());
    return Err(to_anyhow(name.error().message()));
  }

  auto email = toml::try_find<std::string>(config, "user.email");
  if (!email) {
    logger::debug("Failed to get user.email: {}", email.error().message());
    return Err(to_anyhow(email.error().message()));
  }

  return Ok(*name + " <" + *email + ">");
}

[ken-matsui]

Can’t we just return Result from git2 and propagate it via Try?

[adityamwagh]

How about this? My understanding is that Try(config.openDefault()); should store Err or Ok appropriately.

static Result<std::string> getAuthor() noexcept {
  git2::Config config;
  Try(config.openDefault());

  auto name = Try(toml::try_find<std::string>(config, "user.name"));
  auto email = Try(toml::try_find<std::string>(config, "user.email"));

  return Ok(name + " <" + email + ">");
}

[ken-matsui]

getAuthor is not our interest in this issue. We’d like to modify git2 to use/return result, and all use of git2 will need to handle the returned result from git2 appropriately. In theory, we can make almost all functions in gut2 noexcept as a good side effect.