fn build()

in core/src/services/dropbox/builder.rs [132:226]
79 lines of code
4 McCabe index (conditional complexity)

    fn build(self) -> Result<impl Access> {
        let root = normalize_root(&self.config.root.unwrap_or_default());

        let signer = match (self.config.access_token, self.config.refresh_token) {
            (Some(access_token), None) => DropboxSigner {
                access_token,
                // We will never expire user specified token.
                expires_in: DateTime::<Utc>::MAX_UTC,
                ..Default::default()
            },
            (None, Some(refresh_token)) => {
                let client_id = self.config.client_id.ok_or_else(|| {
                    Error::new(
                        ErrorKind::ConfigInvalid,
                        "client_id must be set when refresh_token is set",
                    )
                    .with_context("service", Scheme::Dropbox)
                })?;
                let client_secret = self.config.client_secret.ok_or_else(|| {
                    Error::new(
                        ErrorKind::ConfigInvalid,
                        "client_secret must be set when refresh_token is set",
                    )
                    .with_context("service", Scheme::Dropbox)
                })?;

                DropboxSigner {
                    refresh_token,
                    client_id,
                    client_secret,
                    ..Default::default()
                }
            }
            (Some(_), Some(_)) => {
                return Err(Error::new(
                    ErrorKind::ConfigInvalid,
                    "access_token and refresh_token can not be set at the same time",
                )
                .with_context("service", Scheme::Dropbox))
            }
            (None, None) => {
                return Err(Error::new(
                    ErrorKind::ConfigInvalid,
                    "access_token or refresh_token must be set",
                )
                .with_context("service", Scheme::Dropbox))
            }
        };

        Ok(DropboxBackend {
            core: Arc::new(DropboxCore {
                info: {
                    let am = AccessorInfo::default();
                    am.set_scheme(Scheme::Dropbox)
                        .set_root(&root)
                        .set_native_capability(Capability {
                            stat: true,
                            stat_has_last_modified: true,
                            stat_has_content_length: true,

                            read: true,

                            write: true,

                            create_dir: true,

                            delete: true,

                            list: true,
                            list_with_recursive: true,
                            list_has_last_modified: true,
                            list_has_content_length: true,

                            copy: true,

                            rename: true,

                            shared: true,

                            ..Default::default()
                        });

                    // allow deprecated api here for compatibility
                    #[allow(deprecated)]
                    if let Some(client) = self.http_client {
                        am.update_http_client(|_| client);
                    }

                    am.into()
                },
                root,
                signer: Arc::new(Mutex::new(signer)),
            }),
        })
    }