Fix most clippy warnings (#572)

The only remaining is at `NixInstallerSubcommand`

See https://rust-lang.github.io/rust-clippy/master/index.html#/large_enum_variant

src/action/base/add_user_to_group.rs

@@ -111,7 +111,6 @@ impl AddUserToGroup {
                                 this.groupname
                             );
                             // The group will be created by the installer
-                            ()
                         },
                         _ => {
                             // Some other issue
@@ -131,7 +130,7 @@ impl AddUserToGroup {
                     .await
                     .map_err(Self::error)?;
                     let output_str = String::from_utf8(output.stdout).map_err(Self::error)?;
-                    let user_in_group = output_str.split(" ").any(|v| v == &this.groupname);
+                    let user_in_group = output_str.split(' ').any(|v| v == this.groupname);
 
                     if user_in_group {
                         tracing::debug!(

src/action/base/create_or_merge_nix_config.rs

@@ -35,9 +35,9 @@ pub enum CreateOrMergeNixConfigError {
     UnmergeableConfig(Vec<String>, std::path::PathBuf),
 }
 
-impl Into<ActionErrorKind> for CreateOrMergeNixConfigError {
+impl From<CreateOrMergeNixConfigError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: CreateOrMergeNixConfigError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }
 
@@ -164,7 +164,7 @@ impl CreateOrMergeNixConfig {
             .map_err(Self::error)?;
 
         let (merged_nix_config, existing_nix_config) = Self::merge_pending_and_existing_nix_config(
-            &pending_nix_config,
+            pending_nix_config,
             &existing_nix_config,
             &path,
         )
@@ -273,7 +273,7 @@ impl Action for CreateOrMergeNixConfig {
 
         let (mut merged_nix_config, mut existing_nix_config) = if path.exists() {
             let (merged_nix_config, existing_nix_config) =
-                Self::validate_existing_nix_config(&pending_nix_config, &path)?;
+                Self::validate_existing_nix_config(pending_nix_config, path)?;
             (merged_nix_config, Some(existing_nix_config))
         } else {
             (pending_nix_config.clone(), None)
@@ -342,7 +342,7 @@ impl Action for CreateOrMergeNixConfig {
                 // standalone comments to preserve, but no settings with inline comments.
                 if setting_line.is_empty() {
                     for line in &line_group {
-                        new_config.push_str(&line);
+                        new_config.push_str(line);
                         new_config.push('\n');
                     }
 
@@ -624,20 +624,19 @@ mod test {
             .settings_mut()
             .insert("warn-dirty".into(), "false".into());
         match CreateOrMergeNixConfig::plan(&test_file, nix_config).await {
-            Err(err) => match err.kind() {
+            Err(err) => {
-                ActionErrorKind::Custom(e) => {
+                if let ActionErrorKind::Custom(e) = err.kind() {
                     match e.downcast_ref::<CreateOrMergeNixConfigError>() {
                         Some(CreateOrMergeNixConfigError::UnmergeableConfig(_, path)) => {
                             assert_eq!(path, test_file.as_path())
                         },
                         _ => {
                             return Err(eyre!(
-                            "Should have returned CreateOrMergeNixConfigError::UnmergeableConfig"
+                        "Should have returned CreateOrMergeNixConfigError::UnmergeableConfig"
-                        ))
+                    ))
                         },
                     }
-                },
+                }
-                _ => (),
             },
             _ => {
                 return Err(eyre!(

src/action/base/create_user.rs

@@ -211,7 +211,7 @@ impl Action for CreateUser {
                                 "--home-dir",
                                 "/var/empty",
                                 "--comment",
-                                &comment,
+                                comment,
                                 "--gid",
                                 &gid.to_string(),
                                 "--groups",
@@ -238,7 +238,7 @@ impl Action for CreateUser {
                                 "--home",
                                 "/var/empty",
                                 "--gecos",
-                                &comment,
+                                comment,
                                 "--ingroup",
                                 groupname,
                                 "--system",

src/action/base/fetch_and_unpack_nix.rs

@@ -44,7 +44,7 @@ impl FetchAndUnpackNix {
         }
 
         if let Some(ssl_cert_file) = &ssl_cert_file {
-            parse_ssl_cert(&ssl_cert_file).await.map_err(Self::error)?;
+            parse_ssl_cert(ssl_cert_file).await.map_err(Self::error)?;
         }
 
         Ok(Self {
@@ -105,7 +105,7 @@ impl Action for FetchAndUnpackNix {
                     )
                 }
                 if let Some(ssl_cert_file) = &self.ssl_cert_file {
-                    let ssl_cert = parse_ssl_cert(&ssl_cert_file).await.map_err(Self::error)?;
+                    let ssl_cert = parse_ssl_cert(ssl_cert_file).await.map_err(Self::error)?;
                     buildable_client = buildable_client.add_root_certificate(ssl_cert);
                 }
                 let client = buildable_client
@@ -181,8 +181,8 @@ pub enum FetchUrlError {
     UnknownProxyScheme,
 }
 
-impl Into<ActionErrorKind> for FetchUrlError {
+impl From<FetchUrlError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: FetchUrlError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/base/move_unpacked_nix.rs

@@ -50,7 +50,7 @@ impl Action for MoveUnpackedNix {
 
     fn execute_description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
-            format!("Move the downloaded Nix into `/nix`"),
+            "Move the downloaded Nix into `/nix`".to_string(),
             vec![format!(
                 "Nix is being downloaded to `{}` and should be in `/nix`",
                 self.unpacked_path.display(),
@@ -107,9 +107,7 @@ impl Action for MoveUnpackedNix {
             tracing::trace!(src = %entry.path().display(), dest = %entry_dest.display(), "Renaming");
             tokio::fs::rename(&entry.path(), &entry_dest)
                 .await
-                .map_err(|e| {
+                .map_err(|e| ActionErrorKind::Rename(entry.path(), entry_dest.to_owned(), e))
-                    ActionErrorKind::Rename(entry.path().clone(), entry_dest.to_owned(), e)
-                })
                 .map_err(Self::error)?;
 
             let perms: Permissions = PermissionsExt::from_mode(0o555);
@@ -134,9 +132,7 @@ impl Action for MoveUnpackedNix {
             // eg, know which `nix` version we installed when curing a user with several versions installed
             tokio::fs::symlink(&entry_dest, entry.path())
                 .await
-                .map_err(|e| {
+                .map_err(|e| ActionErrorKind::Symlink(entry_dest.to_owned(), entry.path(), e))
-                    ActionErrorKind::Symlink(entry_dest.to_owned(), entry.path().clone(), e)
-                })
                 .map_err(Self::error)?;
         }
 
@@ -171,8 +167,8 @@ pub enum MoveUnpackedNixError {
     ),
 }
 
-impl Into<ActionErrorKind> for MoveUnpackedNixError {
+impl From<MoveUnpackedNixError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: MoveUnpackedNixError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/base/remove_directory.rs

@@ -19,9 +19,7 @@ impl RemoveDirectory {
         let path = path.as_ref().to_path_buf();
 
         Ok(StatefulAction {
-            action: Self {
+            action: Self { path },
-                path: path.to_path_buf(),
-            },
             state: ActionState::Uncompleted,
         })
     }

src/action/base/setup_default_profile.rs

@@ -54,7 +54,7 @@ impl Action for SetupDefaultProfile {
         // Find an `nix` package
         let nix_pkg_glob = format!("{}/nix-*/store/*-nix-*.*.*", self.unpacked_path.display());
         let mut found_nix_pkg = None;
-        for entry in glob(&nix_pkg_glob).map_err(|e| Self::error(e))? {
+        for entry in glob(&nix_pkg_glob).map_err(Self::error)? {
             match entry {
                 Ok(path) => {
                     // If we are curing, the user may have multiple of these installed
@@ -83,7 +83,7 @@ impl Action for SetupDefaultProfile {
             self.unpacked_path.display()
         );
         let mut found_nss_ca_cert_pkg = None;
-        for entry in glob(&nss_ca_cert_pkg_glob).map_err(|e| Self::error(e))? {
+        for entry in glob(&nss_ca_cert_pkg_glob).map_err(Self::error)? {
             match entry {
                 Ok(path) => {
                     // If we are curing, the user may have multiple of these installed
@@ -109,14 +109,14 @@ impl Action for SetupDefaultProfile {
         };
 
         let found_nix_paths = glob::glob(&format!("{}/nix-*", self.unpacked_path.display()))
-            .map_err(|e| Self::error(e))?
+            .map_err(Self::error)?
             .collect::<Result<Vec<_>, _>>()
-            .map_err(|e| Self::error(e))?;
+            .map_err(Self::error)?;
         if found_nix_paths.len() != 1 {
             return Err(Self::error(ActionErrorKind::MalformedBinaryTarball));
         }
         let found_nix_path = found_nix_paths.into_iter().next().unwrap();
-        let reginfo_path = PathBuf::from(found_nix_path).join(".reginfo");
+        let reginfo_path = found_nix_path.join(".reginfo");
         let reginfo = tokio::fs::read(&reginfo_path)
             .await
             .map_err(|e| ActionErrorKind::Read(reginfo_path.to_path_buf(), e))
@@ -248,8 +248,8 @@ pub enum SetupDefaultProfileError {
     MultipleNixPackages,
 }
 
-impl Into<ActionErrorKind> for SetupDefaultProfileError {
+impl From<SetupDefaultProfileError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: SetupDefaultProfileError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/common/configure_init_service.rs

@@ -402,18 +402,14 @@ impl Action for ConfigureInitService {
                 // We separate stop and disable (instead of using `--now`) to avoid cases where the service isn't started, but is enabled.
 
                 // These have to fail fast.
-                let socket_is_active = is_active("nix-daemon.socket")
+                let socket_is_active = is_active("nix-daemon.socket").await.map_err(Self::error)?;
-                    .await
+                let socket_is_enabled =
-                    .map_err(|e| Self::error(e))?;
+                    is_enabled("nix-daemon.socket").await.map_err(Self::error)?;
-                let socket_is_enabled = is_enabled("nix-daemon.socket")
+                let service_is_active =
-                    .await
+                    is_active("nix-daemon.service").await.map_err(Self::error)?;
-                    .map_err(|e| Self::error(e))?;
-                let service_is_active = is_active("nix-daemon.service")
-                    .await
-                    .map_err(|e| Self::error(e))?;
                 let service_is_enabled = is_enabled("nix-daemon.service")
                     .await
-                    .map_err(|e| Self::error(e))?;
+                    .map_err(Self::error)?;
 
                 if socket_is_active {
                     if let Err(err) = execute_command(

src/action/common/create_nix_tree.rs

@@ -65,7 +65,7 @@ impl Action for CreateNixTree {
 
         let mut create_directory_descriptions = Vec::new();
         for create_directory in create_directories {
-            if let Some(val) = create_directory.describe_execute().iter().next() {
+            if let Some(val) = create_directory.describe_execute().first() {
                 create_directory_descriptions.push(val.description.clone())
             }
         }
@@ -87,7 +87,7 @@ impl Action for CreateNixTree {
 
     fn revert_description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
-            format!("Remove the directory tree in `/nix`"),
+            "Remove the directory tree in `/nix`".to_string(),
             vec![
                 format!(
                     "Nix and the Nix daemon require a Nix Store, which will be stored at `/nix`"

src/action/common/create_users_and_groups.rs

@@ -110,14 +110,14 @@ impl Action for CreateUsersAndGroups {
 
         let mut create_users_descriptions = Vec::new();
         for create_user in create_users {
-            if let Some(val) = create_user.describe_execute().iter().next() {
+            if let Some(val) = create_user.describe_execute().first() {
                 create_users_descriptions.push(val.description.clone())
             }
         }
 
         let mut add_user_to_group_descriptions = Vec::new();
         for add_user_to_group in add_users_to_groups {
-            if let Some(val) = add_user_to_group.describe_execute().iter().next() {
+            if let Some(val) = add_user_to_group.describe_execute().first() {
                 add_user_to_group_descriptions.push(val.description.clone())
             }
         }
@@ -125,7 +125,7 @@ impl Action for CreateUsersAndGroups {
         let mut explanation = vec![
             format!("The Nix daemon requires system users (and a group they share) which it can act as in order to build"),
         ];
-        if let Some(val) = create_group.describe_execute().iter().next() {
+        if let Some(val) = create_group.describe_execute().first() {
             explanation.push(val.description.clone())
         }
         explanation.append(&mut create_users_descriptions);
@@ -222,14 +222,14 @@ impl Action for CreateUsersAndGroups {
         } = &self;
         let mut create_users_descriptions = Vec::new();
         for create_user in create_users {
-            if let Some(val) = create_user.describe_revert().iter().next() {
+            if let Some(val) = create_user.describe_revert().first() {
                 create_users_descriptions.push(val.description.clone())
             }
         }
 
         let mut add_user_to_group_descriptions = Vec::new();
         for add_user_to_group in add_users_to_groups {
-            if let Some(val) = add_user_to_group.describe_revert().iter().next() {
+            if let Some(val) = add_user_to_group.describe_revert().first() {
                 add_user_to_group_descriptions.push(val.description.clone())
             }
         }
@@ -237,7 +237,7 @@ impl Action for CreateUsersAndGroups {
         let mut explanation = vec![
             format!("The Nix daemon requires system users (and a group they share) which it can act as in order to build"),
         ];
-        if let Some(val) = create_group.describe_revert().iter().next() {
+        if let Some(val) = create_group.describe_revert().first() {
             explanation.push(val.description.clone())
         }
         explanation.append(&mut create_users_descriptions);
@@ -245,12 +245,12 @@ impl Action for CreateUsersAndGroups {
 
         if create_users.is_empty() {
             vec![ActionDescription::new(
-                format!("Remove Nix group"),
+                "Remove Nix group".to_string(),
                 explanation,
             )]
         } else {
             vec![ActionDescription::new(
-                format!("Remove Nix users and group"),
+                "Remove Nix users and group".to_string(),
                 explanation,
             )]
         }

src/action/common/delete_users.rs

@@ -58,7 +58,7 @@ impl Action for DeleteUsersInGroup {
     fn execute_description(&self) -> Vec<ActionDescription> {
         let mut delete_users_descriptions = Vec::new();
         for delete_user in self.delete_users.iter() {
-            if let Some(val) = delete_user.describe_execute().iter().next() {
+            if let Some(val) = delete_user.describe_execute().first() {
                 delete_users_descriptions.push(val.description.clone())
             }
         }
@@ -82,7 +82,7 @@ impl Action for DeleteUsersInGroup {
     fn revert_description(&self) -> Vec<ActionDescription> {
         let mut delete_users_descriptions = Vec::new();
         for delete_user in self.delete_users.iter() {
-            if let Some(val) = delete_user.describe_revert().iter().next() {
+            if let Some(val) = delete_user.describe_revert().first() {
                 delete_users_descriptions.push(val.description.clone())
             }
         }

src/action/common/place_nix_configuration.rs

@@ -47,7 +47,7 @@ impl PlaceNixConfiguration {
                 }
             },
             Entry::Vacant(slot) => {
-                let _ = slot.insert(experimental_features.join(" ").to_string());
+                let _ = slot.insert(experimental_features.join(" "));
             },
         };
 
@@ -117,7 +117,7 @@ impl Action for PlaceNixConfiguration {
                 .to_string(),
         ];
 
-        if let Some(val) = create_directory.describe_execute().iter().next() {
+        if let Some(val) = create_directory.describe_execute().first() {
             explanation.push(val.description.clone())
         }
         for val in create_or_merge_nix_config.describe_execute().iter() {

src/action/linux/ensure_steamos_nix_directory.rs

@@ -42,7 +42,7 @@ impl Action for EnsureSteamosNixDirectory {
         ActionTag("ensure_steamos_nix_directory")
     }
     fn tracing_synopsis(&self) -> String {
-        format!("Ensure SteamOS's `/nix` directory exists")
+        "Ensure SteamOS's `/nix` directory exists".to_string()
     }
 
     fn tracing_span(&self) -> Span {

src/action/linux/provision_selinux.rs

@@ -37,7 +37,7 @@ impl Action for ProvisionSelinux {
         ActionTag("provision_selinux")
     }
     fn tracing_synopsis(&self) -> String {
-        format!("Install an SELinux Policy for Nix")
+        "Install an SELinux Policy for Nix".to_string()
     }
 
     fn tracing_span(&self) -> Span {

src/action/linux/revert_clean_steamos_nix_offload.rs

@@ -6,7 +6,7 @@ use crate::action::{ActionError, ActionErrorKind, ActionTag};
 
 use crate::action::{Action, ActionDescription, StatefulAction};
 
-const OFFLOAD_PATH: &'static str = "/home/.steamos/offload/nix";
+const OFFLOAD_PATH: &str = "/home/.steamos/offload/nix";
 
 /**
 Clean out the `/home/.steamos/offload/nix`
@@ -71,7 +71,7 @@ impl Action for RevertCleanSteamosNixOffload {
             tracing::trace!(path = %path.display(), "Removing");
             tokio::fs::remove_dir_all(&path)
                 .await
-                .map_err(|e| Self::error(ActionErrorKind::Remove(path.into(), e)))?;
+                .map_err(|e| Self::error(ActionErrorKind::Remove(path, e)))?;
         }
 
         Ok(())

src/action/linux/start_systemd_unit.rs

@@ -81,7 +81,7 @@ impl Action for StartSystemdUnit {
                         .process_group(0)
                         .arg("enable")
                         .arg("--now")
-                        .arg(format!("{unit}"))
+                        .arg(&unit)
                         .stdin(std::process::Stdio::null()),
                 )
                 .await
@@ -93,7 +93,7 @@ impl Action for StartSystemdUnit {
                     Command::new("systemctl")
                         .process_group(0)
                         .arg("start")
-                        .arg(format!("{unit}"))
+                        .arg(&unit)
                         .stdin(std::process::Stdio::null()),
                 )
                 .await
@@ -120,7 +120,7 @@ impl Action for StartSystemdUnit {
                 Command::new("systemctl")
                     .process_group(0)
                     .arg("disable")
-                    .arg(format!("{}", self.unit))
+                    .arg(&self.unit)
                     .stdin(std::process::Stdio::null()),
             )
             .await
@@ -135,7 +135,7 @@ impl Action for StartSystemdUnit {
             Command::new("systemctl")
                 .process_group(0)
                 .arg("stop")
-                .arg(format!("{}", self.unit))
+                .arg(&self.unit)
                 .stdin(std::process::Stdio::null()),
         )
         .await

src/action/linux/systemctl_daemon_reload.rs

@@ -36,7 +36,7 @@ impl Action for SystemctlDaemonReload {
         ActionTag("systemctl_daemon_reload")
     }
     fn tracing_synopsis(&self) -> String {
-        format!("Run `systemctl daemon-reload`")
+        "Run `systemctl daemon-reload`".to_string()
     }
 
     fn tracing_span(&self) -> Span {

src/action/macos/bootstrap_launchctl_service.rs

@@ -47,11 +47,7 @@ impl BootstrapLaunchctlService {
                 .await
                 .map_err(|e| Self::error(ActionErrorKind::command(&command, e)))?;
             // We presume that success means it's found
-            if command_output.status.success() || command_output.status.code() == Some(37) {
+            command_output.status.success() || command_output.status.code() == Some(37)
-                true
-            } else {
-                false
-            }
         };
 
         let is_disabled = service_is_disabled(&domain, &service)

src/action/macos/create_fstab_entry.rs

@@ -122,7 +122,7 @@ impl Action for CreateFstabEntry {
             existing_entry,
         } = self;
         let fstab_path = Path::new(FSTAB_PATH);
-        let uuid = match get_uuid_for_label(&apfs_volume_label)
+        let uuid = match get_uuid_for_label(apfs_volume_label)
             .await
             .map_err(Self::error)?
         {
@@ -158,7 +158,7 @@ impl Action for CreateFstabEntry {
                     .collect::<Vec<String>>();
                 let mut updated_line = false;
                 let mut saw_prelude = false;
-                let prelude = fstab_prelude_comment(&apfs_volume_label);
+                let prelude = fstab_prelude_comment(apfs_volume_label);
                 for line in current_fstab_lines.iter_mut() {
                     if line == &prelude {
                         saw_prelude = true;
@@ -306,8 +306,8 @@ pub enum CreateFstabEntryError {
     CannotDetermineFstabLine,
 }
 
-impl Into<ActionErrorKind> for CreateFstabEntryError {
+impl From<CreateFstabEntryError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: CreateFstabEntryError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/macos/create_volume_service.rs

@@ -117,7 +117,7 @@ impl CreateVolumeService {
                             .await
                             .map_err(|e| Self::error(ActionErrorKind::Read(fstab, e)))?;
                         for line in contents.lines() {
-                            if line.starts_with("#") {
+                            if line.starts_with('#') {
                                 continue;
                             }
                             let split = line.split_whitespace();
@@ -204,7 +204,7 @@ impl Action for CreateVolumeService {
             }
         }
 
-        let uuid = match get_uuid_for_label(&apfs_volume_label)
+        let uuid = match get_uuid_for_label(apfs_volume_label)
             .await
             .map_err(Self::error)?
         {
@@ -216,8 +216,8 @@ impl Action for CreateVolumeService {
             },
         };
         let generated_plist = generate_mount_plist(
-            &mount_service_label,
+            mount_service_label,
-            &apfs_volume_label,
+            apfs_volume_label,
             uuid,
             mount_point,
             *encrypt,
@@ -315,8 +315,8 @@ pub enum CreateVolumeServiceError {
     VolumeDoesNotExistButVolumeServiceAndFstabEntryDoes(PathBuf, String),
 }
 
-impl Into<ActionErrorKind> for CreateVolumeServiceError {
+impl From<CreateVolumeServiceError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: CreateVolumeServiceError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/macos/enable_ownership.rs

@@ -104,8 +104,8 @@ pub enum EnableOwnershipError {
     Command(#[source] std::io::Error),
 }
 
-impl Into<ActionErrorKind> for EnableOwnershipError {
+impl From<EnableOwnershipError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: EnableOwnershipError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/macos/encrypt_apfs_volume.rs

@@ -64,13 +64,11 @@ impl EncryptApfsVolume {
             return Err(Self::error(EncryptApfsVolumeError::ExistingPasswordFound(
                 name, disk,
             )));
-        } else {
+        } else if planned_create_apfs_volume.state == ActionState::Completed {
-            if planned_create_apfs_volume.state == ActionState::Completed {
+            // The user has a volume already created, but a password not set. This means we probably can't decrypt the volume.
-                // The user has a volume already created, but a password not set. This means we probably can't decrypt the volume.
+            return Err(Self::error(
-                return Err(Self::error(
+                EncryptApfsVolumeError::MissingPasswordForExistingVolume(name, disk),
-                    EncryptApfsVolumeError::MissingPasswordForExistingVolume(name, disk),
+            ));
-                ));
-            }
         }
 
         // Ensure if the disk already exists, that it's encrypted
@@ -84,15 +82,12 @@ impl EncryptApfsVolume {
         for container in parsed.containers {
             for volume in container.volumes {
                 if volume.name.as_ref() == Some(&name) {
-                    match volume.encryption == false {
+                    if volume.encryption {
-                        true => {
+                        return Err(Self::error(
-                            return Ok(StatefulAction::completed(Self { disk, name }));
+                            EncryptApfsVolumeError::ExistingVolumeNotEncrypted(name, disk),
-                        },
+                        ));
-                        false => {
+                    } else {
-                            return Err(Self::error(
+                        return Ok(StatefulAction::completed(Self { disk, name }));
-                                EncryptApfsVolumeError::ExistingVolumeNotEncrypted(name, disk),
-                            ));
-                        },
                     }
                 }
             }
@@ -265,8 +260,8 @@ pub enum EncryptApfsVolumeError {
     ExistingVolumeNotEncrypted(String, PathBuf),
 }
 
-impl Into<ActionErrorKind> for EncryptApfsVolumeError {
+impl From<EncryptApfsVolumeError> for ActionErrorKind {
-    fn into(self) -> ActionErrorKind {
+    fn from(val: EncryptApfsVolumeError) -> Self {
-        ActionErrorKind::Custom(Box::new(self))
+        ActionErrorKind::Custom(Box::new(val))
     }
 }

src/action/macos/kickstart_launchctl_service.rs

@@ -43,7 +43,7 @@ impl KickstartLaunchctlService {
         if output.status.success() {
             service_exists = true;
 
-            let output_string = String::from_utf8(output.stdout).map_err(|e| Self::error(e))?;
+            let output_string = String::from_utf8(output.stdout).map_err(Self::error)?;
             // We are looking for a line containing "state = " with some trailing content
             // The output is not a JSON or a plist
             // MacOS's man pages explicitly tell us not to try to parse this output

src/action/macos/mod.rs

@@ -55,12 +55,12 @@ async fn get_uuid_for_label(apfs_volume_label: &str) -> Result<Option<Uuid>, Act
     if let Some(error_message) = parsed.error_message {
         let expected_not_found = format!("Could not find disk: {apfs_volume_label}");
         if error_message.contains(&expected_not_found) {
-            return Ok(None);
+            Ok(None)
         } else {
-            return Err(ActionErrorKind::DiskUtilInfoError {
+            Err(ActionErrorKind::DiskUtilInfoError {
                 command: command_str,
                 message: error_message,
-            });
+            })
         }
     } else if let Some(uuid) = parsed.volume_uuid {
         Ok(Some(uuid))
@@ -86,7 +86,7 @@ pub(crate) async fn service_is_disabled(
     let output = execute_command(
         Command::new("launchctl")
             .arg("print-disabled")
-            .arg(&domain)
+            .arg(domain)
             .stdin(std::process::Stdio::null())
             .stdout(std::process::Stdio::piped())
             .stderr(std::process::Stdio::piped()),

src/action/macos/set_tmutil_exclusions.rs

@@ -78,7 +78,7 @@ impl Action for SetTmutilExclusions {
 
         let mut set_tmutil_exclusion_descriptions = Vec::new();
         for set_tmutil_exclusion in set_tmutil_exclusions {
-            if let Some(val) = set_tmutil_exclusion.describe_execute().iter().next() {
+            if let Some(val) = set_tmutil_exclusion.describe_execute().first() {
                 set_tmutil_exclusion_descriptions.push(val.description.clone())
             }
         }
@@ -103,7 +103,7 @@ impl Action for SetTmutilExclusions {
 
     fn revert_description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
-            format!("Remove time machine exclusions"),
+            "Remove time machine exclusions".to_string(),
             vec![],
         )]
     }

src/action/macos/unmount_apfs_volume.rs

@@ -69,7 +69,7 @@ impl Action for UnmountApfsVolume {
             .map_err(Self::error)?
             .stdout;
             let the_plist: DiskUtilInfoOutput =
-                plist::from_reader(Cursor::new(buf)).map_err(|e| Self::error(e))?;
+                plist::from_reader(Cursor::new(buf)).map_err(Self::error)?;
 
             the_plist.mount_point.is_some()
         };
@@ -111,7 +111,7 @@ impl Action for UnmountApfsVolume {
             .map_err(Self::error)?
             .stdout;
             let the_plist: DiskUtilInfoOutput =
-                plist::from_reader(Cursor::new(buf)).map_err(|e| Self::error(e))?;
+                plist::from_reader(Cursor::new(buf)).map_err(Self::error)?;
 
             the_plist.mount_point.is_some()
         };

src/action/mod.rs

@@ -635,7 +635,7 @@ impl crate::diagnostics::ErrorDiagnostic for ActionErrorKind {
             },
             _ => vec![],
         };
-        return format!(
+        format!(
             "{}({})",
             static_str,
             context
@@ -643,6 +643,6 @@ impl crate::diagnostics::ErrorDiagnostic for ActionErrorKind {
                 .map(|v| format!("\"{v}\""))
                 .collect::<Vec<_>>()
                 .join(", ")
-        );
+        )
     }
 }

src/action/stateful.rs

@@ -145,14 +145,14 @@ where
         if self.state == ActionState::Completed {
             return vec![];
         }
-        return self.action.execute_description();
+        self.action.execute_description()
     }
     /// A description of what this action would do during revert
     pub fn describe_revert(&self) -> Vec<ActionDescription> {
         if self.state == ActionState::Uncompleted {
             return vec![];
         }
-        return self.action.revert_description();
+        self.action.revert_description()
     }
     /// Perform any execution steps
     ///

src/cli/arg/instrumentation.rs

@@ -139,7 +139,7 @@ impl<'a> Instrumentation {
                 }
                 EnvFilter::try_new(&format!(
                     "{}={}",
-                    env!("CARGO_PKG_NAME").replace("-", "_"),
+                    env!("CARGO_PKG_NAME").replace('-', "_"),
                     self.log_level()
                 ))?
             },

src/cli/mod.rs

@@ -123,7 +123,7 @@ pub fn ensure_root() -> eyre::Result<()> {
         if is_ci::cached() {
             // Normally `sudo` would erase those envs, so we detect and pass that along specifically to avoid having to pass around
             // a bunch of environment variables
-            env_list.push(format!("NIX_INSTALLER_CI=1"));
+            env_list.push("NIX_INSTALLER_CI=1".to_string());
         }
 
         if !env_list.is_empty() {

src/cli/subcommand/install.rs

@@ -24,7 +24,7 @@ use color_eyre::{
 };
 use owo_colors::OwoColorize;
 
-const EXISTING_INCOMPATIBLE_PLAN_GUIDANCE: &'static str = "\
+const EXISTING_INCOMPATIBLE_PLAN_GUIDANCE: &str = "\
     If you are trying to upgrade Nix, try running `sudo -i nix upgrade-nix` instead.\n\
     If you are trying to install Nix over an existing install (from an incompatible `nix-installer` install), try running `/nix/nix-installer uninstall` then try to install again.\n\
     If you are using `nix-installer` in an automated curing process and seeing this message, consider pinning the version you use via https://github.com/DeterminateSystems/nix-installer#accessing-other-versions.\

src/diagnostics.rs

@@ -174,14 +174,12 @@ impl DiagnosticData {
                 tracing::debug!("Sending diagnostic to `{endpoint}`");
                 let mut buildable_client = reqwest::Client::builder();
                 if let Some(ssl_cert_file) = &self.ssl_cert_file {
-                    let ssl_cert = parse_ssl_cert(&ssl_cert_file).await.ok();
+                    let ssl_cert = parse_ssl_cert(ssl_cert_file).await.ok();
                     if let Some(ssl_cert) = ssl_cert {
                         buildable_client = buildable_client.add_root_certificate(ssl_cert);
                     }
                 }
-                let client = buildable_client
+                let client = buildable_client.build().map_err(DiagnosticError::Reqwest)?;
-                    .build()
-                    .map_err(|e| DiagnosticError::Reqwest(e))?;
 
                 let res = client
                     .post(endpoint.clone())
@@ -247,7 +245,7 @@ pub trait ErrorDiagnostic {
 impl ErrorDiagnostic for DiagnosticError {
     fn diagnostic(&self) -> String {
         let static_str: &'static str = (self).into();
-        return static_str.to_string();
+        static_str.to_string()
     }
 }
 

src/error.rs

@@ -128,16 +128,16 @@ impl crate::diagnostics::ErrorDiagnostic for NixInstallerError {
         let context = match self {
             Self::SelfTest(self_tests) => self_tests
                 .iter()
-                .map(|self_test| self_test.diagnostic().to_string())
+                .map(|self_test| self_test.diagnostic())
                 .collect::<Vec<_>>(),
-            Self::Action(action_error) => vec![action_error.diagnostic().to_string()],
+            Self::Action(action_error) => vec![action_error.diagnostic()],
             Self::ActionRevert(action_errors) => action_errors
                 .iter()
-                .map(|action_error| action_error.diagnostic().to_string())
+                .map(|action_error| action_error.diagnostic())
                 .collect(),
             _ => vec![],
         };
-        return format!(
+        format!(
             "{}({})",
             static_str,
             context
@@ -145,6 +145,6 @@ impl crate::diagnostics::ErrorDiagnostic for NixInstallerError {
                 .map(|v| format!("\"{v}\""))
                 .collect::<Vec<_>>()
                 .join(", ")
-        );
+        )
     }
 }

src/plan.rs

@@ -128,8 +128,7 @@ impl InstallPlan {
             },
             actions = actions
                 .iter()
-                .map(|v| v.describe_execute())
+                .flat_map(|v| v.describe_execute())
-                .flatten()
                 .map(|desc| {
                     let ActionDescription {
                         description,
@@ -300,8 +299,7 @@ impl InstallPlan {
             actions = actions
                 .iter()
                 .rev()
-                .map(|v| v.describe_revert())
+                .flat_map(|v| v.describe_revert())
-                .flatten()
                 .map(|desc| {
                     let ActionDescription {
                         description,
@@ -394,7 +392,7 @@ impl InstallPlan {
                     .await?;
             }
 
-            return Err(error);
+            Err(error)
         }
     }
 

src/planner/linux.rs

@@ -156,9 +156,9 @@ impl Planner for Linux {
     }
 }
 
-impl Into<BuiltinPlanner> for Linux {
+impl From<Linux> for BuiltinPlanner {
-    fn into(self) -> BuiltinPlanner {
+    fn from(val: Linux) -> Self {
-        BuiltinPlanner::Linux(self)
+        BuiltinPlanner::Linux(val)
     }
 }
 
@@ -196,11 +196,12 @@ pub(crate) async fn detect_selinux() -> Result<bool, PlannerError> {
 
 pub(crate) async fn check_nix_not_already_installed() -> Result<(), PlannerError> {
     // For now, we don't try to repair the user's Nix install or anything special.
-    if let Ok(_) = Command::new("nix-env")
+    if Command::new("nix-env")
         .arg("--version")
         .stdin(std::process::Stdio::null())
         .status()
         .await
+        .is_ok()
     {
         return Err(PlannerError::NixExists);
     }

src/planner/mod.rs

@@ -443,6 +443,6 @@ impl HasExpectedErrors for PlannerError {
 impl crate::diagnostics::ErrorDiagnostic for PlannerError {
     fn diagnostic(&self) -> String {
         let static_str: &'static str = (self).into();
-        return static_str.to_string();
+        static_str.to_string()
     }
 }

src/planner/steam_deck.rs

@@ -179,8 +179,7 @@ impl Planner for SteamDeck {
                     .boxed(),
             );
 
-            let nix_directory_buf = format!(
+            let nix_directory_buf = "\
-                "\
                 [Unit]\n\
                 Description=Create a `/nix` directory to be used for bind mounting\n\
                 PropagatesStopTo=nix-daemon.service\n\
@@ -202,7 +201,7 @@ impl Planner for SteamDeck {
                 ExecStop=steamos-readonly enable\n\
                 RemainAfterExit=true\n\
             "
-            );
+            .to_string();
             let nix_directory_unit = CreateFile::plan(
                 "/etc/systemd/system/nix-directory.service",
                 None,
@@ -267,8 +266,7 @@ impl Planner for SteamDeck {
             actions.push(start_nix_mount.boxed());
         }
 
-        let ensure_symlinked_units_resolve_buf = format!(
+        let ensure_symlinked_units_resolve_buf = "\
-            "\
             [Unit]\n\
             Description=Ensure Nix related units which are symlinked resolve\n\
             After=nix.mount\n\
@@ -284,7 +282,7 @@ impl Planner for SteamDeck {
             [Install]\n\
             WantedBy=sysinit.target\n\
         "
-        );
+        .to_string();
         let ensure_symlinked_units_resolve_unit = CreateFile::plan(
             "/etc/systemd/system/ensure-symlinked-units-resolve.service",
             None,
@@ -422,9 +420,9 @@ impl Planner for SteamDeck {
     }
 }
 
-impl Into<BuiltinPlanner> for SteamDeck {
+impl From<SteamDeck> for BuiltinPlanner {
-    fn into(self) -> BuiltinPlanner {
+    fn from(val: SteamDeck) -> Self {
-        BuiltinPlanner::SteamDeck(self)
+        BuiltinPlanner::SteamDeck(val)
     }
 }
 
@@ -445,8 +443,7 @@ pub(crate) async fn detect_requires_bind_mount() -> Result<bool, PlannerError> {
     let steamos_nix_mount_unit_path = "/usr/lib/systemd/system/nix.mount";
     let nix_mount_unit = tokio::fs::read_to_string(steamos_nix_mount_unit_path)
         .await
-        .map(|v| Some(v))
+        .ok();
-        .unwrap_or_else(|_| None);
 
     match nix_mount_unit {
         Some(nix_mount_unit) if nix_mount_unit.contains("What=/home/.steamos/offload/nix") => {

src/self_test.rs

@@ -35,7 +35,7 @@ impl crate::diagnostics::ErrorDiagnostic for SelfTestError {
             Self::Command { shell, .. } => vec![shell.to_string()],
             Self::SystemTime(_) => vec![],
         };
-        return format!(
+        format!(
             "{}({})",
             static_str,
             context
@@ -43,7 +43,7 @@ impl crate::diagnostics::ErrorDiagnostic for SelfTestError {
                 .map(|v| format!("\"{v}\""))
                 .collect::<Vec<_>>()
                 .join(", ")
-        );
+        )
     }
 }
 

src/settings.rs

@@ -372,7 +372,7 @@ async fn linux_detect_systemd_started() -> bool {
 
     let mut started = false;
     if std::path::Path::new("/run/systemd/system").exists() {
-        started = if tokio::process::Command::new("systemctl")
+        started = tokio::process::Command::new("systemctl")
             .arg("status")
             .stdin(Stdio::null())
             .stdout(Stdio::null())
@@ -382,11 +382,6 @@ async fn linux_detect_systemd_started() -> bool {
             .ok()
             .map(|exit| exit.success())
             .unwrap_or(false)
-        {
-            true
-        } else {
-            false
-        }
     }
 
     // TODO: Other inits
@@ -509,6 +504,6 @@ pub enum InstallSettingsError {
 impl crate::diagnostics::ErrorDiagnostic for InstallSettingsError {
     fn diagnostic(&self) -> String {
         let static_str: &'static str = (self).into();
-        return static_str.to_string();
+        static_str.to_string()
     }
 }