diff --git a/crates/synd_term/src/application/cache/mod.rs b/crates/synd_term/src/application/cache/mod.rs
index 62d81527..c455bdff 100644
--- a/crates/synd_term/src/application/cache/mod.rs
+++ b/crates/synd_term/src/application/cache/mod.rs
@@ -3,16 +3,30 @@ use std::{borrow::Borrow, io, path::PathBuf};
 use crate::{
     auth::{Credential, CredentialError, Unverified},
     config,
+    filesystem::{fsimpl, FileSystem},
     ui::components::gh_notifications::GhNotificationFilterOptions,
 };
 
-pub struct Cache {
+pub struct Cache<FS = fsimpl::FileSystem> {
     dir: PathBuf,
+    fs: FS,
 }
 
-impl Cache {
+impl Cache<fsimpl::FileSystem> {
     pub fn new(dir: impl Into<PathBuf>) -> Self {
-        Self { dir: dir.into() }
+        Self::with(dir, fsimpl::FileSystem::new())
+    }
+}
+
+impl<FS> Cache<FS>
+where
+    FS: FileSystem,
+{
+    pub fn with(dir: impl Into<PathBuf>, fs: FS) -> Self {
+        Self {
+            dir: dir.into(),
+            fs,
+        }
     }
 
     /// Persist credential in filesystem.
@@ -85,7 +99,7 @@ impl Cache {
     pub(crate) fn clean(&self) -> io::Result<()> {
         // User can specify any directory as the cache
         // so instead of deleting the entire directory with `remove_dir_all`, delete files individually.
-        match std::fs::remove_file(self.credential_file()) {
+        match self.fs.remove_file(self.credential_file()) {
             Ok(()) => Ok(()),
             Err(err) => match err.kind() {
                 io::ErrorKind::NotFound => Ok(()),
diff --git a/crates/synd_term/src/cli/clean.rs b/crates/synd_term/src/cli/clean.rs
deleted file mode 100644
index 327fa880..00000000
--- a/crates/synd_term/src/cli/clean.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-use std::{io::ErrorKind, path::PathBuf};
-
-use anyhow::Context;
-use clap::Args;
-
-use crate::{application::Cache, config};
-
-/// Clean cache and logs
-#[derive(Args, Debug)]
-pub struct CleanCommand {
-    /// Cache directory
-    #[arg(
-        long,
-        default_value = config::cache::dir().to_path_buf().into_os_string(),
-    )]
-    cache_dir: PathBuf,
-}
-
-impl CleanCommand {
-    #[allow(clippy::unused_self)]
-    pub fn run(self) -> i32 {
-        if let Err(err) = self.clean() {
-            tracing::error!("{err}");
-            1
-        } else {
-            0
-        }
-    }
-
-    fn clean(self) -> anyhow::Result<()> {
-        let CleanCommand { cache_dir } = self;
-
-        let cache = Cache::new(&cache_dir);
-        cache
-            .clean()
-            .map_err(anyhow::Error::from)
-            .with_context(|| format!("path: {}", cache_dir.display()))?;
-
-        // remove log
-        let log_file = config::log_path();
-        match std::fs::remove_file(&log_file) {
-            Ok(()) => {
-                tracing::info!("Remove {}", log_file.display());
-            }
-            Err(err) => match err.kind() {
-                ErrorKind::NotFound => {}
-                _ => {
-                    return Err(anyhow::Error::from(err))
-                        .with_context(|| format!("path: {}", log_file.display()))
-                }
-            },
-        }
-
-        Ok(())
-    }
-}
diff --git a/crates/synd_term/src/cli/check.rs b/crates/synd_term/src/cli/command/check.rs
similarity index 93%
rename from crates/synd_term/src/cli/check.rs
rename to crates/synd_term/src/cli/command/check.rs
index 2b7bbf61..9c3f0e3e 100644
--- a/crates/synd_term/src/cli/check.rs
+++ b/crates/synd_term/src/cli/command/check.rs
@@ -1,4 +1,4 @@
-use std::{io, path::Path, time::Duration};
+use std::{io, path::Path, process::ExitCode, time::Duration};
 
 use anyhow::Context;
 use clap::Args;
@@ -22,12 +22,12 @@ pub struct CheckCommand {
 
 impl CheckCommand {
     #[allow(clippy::unused_self)]
-    pub async fn run(self, endpoint: Url) -> i32 {
+    pub async fn run(self, endpoint: Url) -> ExitCode {
         if let Err(err) = self.check(endpoint).await {
             tracing::error!("{err:?}");
-            1
+            ExitCode::from(1)
         } else {
-            0
+            ExitCode::SUCCESS
         }
     }
 
diff --git a/crates/synd_term/src/cli/command/clean.rs b/crates/synd_term/src/cli/command/clean.rs
new file mode 100644
index 00000000..e4942019
--- /dev/null
+++ b/crates/synd_term/src/cli/command/clean.rs
@@ -0,0 +1,116 @@
+use std::{
+    io::ErrorKind,
+    path::{Path, PathBuf},
+    process::ExitCode,
+};
+
+use anyhow::Context;
+use clap::Args;
+
+use crate::{application::Cache, config, filesystem::FileSystem};
+
+/// Clean cache and logs
+#[derive(Args, Debug)]
+pub struct CleanCommand {
+    /// Cache directory
+    #[arg(
+        long,
+        default_value = config::cache::dir().to_path_buf().into_os_string(),
+    )]
+    cache_dir: PathBuf,
+}
+
+impl CleanCommand {
+    #[allow(clippy::unused_self)]
+    pub fn run<FS>(self, fs: &FS) -> ExitCode
+    where
+        FS: FileSystem + Clone,
+    {
+        ExitCode::from(self.clean(fs, config::log_path().as_path()))
+    }
+
+    fn clean<FS>(self, fs: &FS, log: &Path) -> u8
+    where
+        FS: FileSystem + Clone,
+    {
+        if let Err(err) = self.try_clean(fs, log) {
+            tracing::error!("{err}");
+            1
+        } else {
+            0
+        }
+    }
+    fn try_clean<FS>(self, fs: &FS, log: &Path) -> anyhow::Result<()>
+    where
+        FS: FileSystem + Clone,
+    {
+        let CleanCommand { cache_dir } = self;
+
+        let cache = Cache::with(&cache_dir, fs.clone());
+        cache
+            .clean()
+            .map_err(anyhow::Error::from)
+            .with_context(|| format!("path: {}", cache_dir.display()))?;
+
+        // remove log
+        match fs.remove_file(log) {
+            Ok(()) => {
+                tracing::info!("Remove {}", log.display());
+            }
+            Err(err) => match err.kind() {
+                ErrorKind::NotFound => {}
+                _ => {
+                    return Err(anyhow::Error::from(err))
+                        .with_context(|| format!("path: {}", log.display()))
+                }
+            },
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io;
+
+    use tempfile::{NamedTempFile, TempDir};
+
+    use crate::filesystem::{fsimpl, mock::MockFileSystem};
+
+    use super::*;
+
+    #[test]
+    fn remove_log_file() {
+        let clean = CleanCommand {
+            cache_dir: TempDir::new().unwrap().into_path(),
+        };
+        let log_file = NamedTempFile::new().unwrap();
+        let exit_code = clean.clean(&fsimpl::FileSystem::new(), log_file.path());
+        assert_eq!(exit_code, 0);
+        assert!(!log_file.path().exists());
+    }
+
+    #[test]
+    fn ignore_log_file_not_found() {
+        let clean = CleanCommand {
+            cache_dir: TempDir::new().unwrap().into_path(),
+        };
+        let log_file = Path::new("./not_exists");
+        let fs = MockFileSystem::default().with_remove_errors(log_file, io::ErrorKind::NotFound);
+        let exit_code = clean.clean(&fs, log_file);
+        assert_eq!(exit_code, 0);
+    }
+
+    #[test]
+    fn exit_code_on_permission_error() {
+        let clean = CleanCommand {
+            cache_dir: TempDir::new().unwrap().into_path(),
+        };
+        let log_file = Path::new("./not_allowed");
+        let fs =
+            MockFileSystem::default().with_remove_errors(log_file, io::ErrorKind::PermissionDenied);
+        let exit_code = clean.clean(&fs, log_file);
+        assert_eq!(exit_code, 1);
+    }
+}
diff --git a/crates/synd_term/src/cli/export.rs b/crates/synd_term/src/cli/command/export.rs
similarity index 93%
rename from crates/synd_term/src/cli/export.rs
rename to crates/synd_term/src/cli/command/export.rs
index 03429a12..c3bdc627 100644
--- a/crates/synd_term/src/cli/export.rs
+++ b/crates/synd_term/src/cli/command/export.rs
@@ -1,4 +1,4 @@
-use std::{path::PathBuf, time::Duration};
+use std::{path::PathBuf, process::ExitCode, time::Duration};
 
 use anyhow::anyhow;
 use clap::Args;
@@ -39,7 +39,7 @@ pub struct ExportCommand {
 }
 
 impl ExportCommand {
-    pub async fn run(self, endpoint: Url) -> i32 {
+    pub async fn run(self, endpoint: Url) -> ExitCode {
         let err = if self.print_schema {
             Self::print_json_schema()
         } else {
@@ -47,9 +47,9 @@ impl ExportCommand {
         };
         if let Err(err) = err {
             tracing::error!("{err:?}");
-            1
+            ExitCode::from(1)
         } else {
-            0
+            ExitCode::SUCCESS
         }
     }
 
diff --git a/crates/synd_term/src/cli/command/mod.rs b/crates/synd_term/src/cli/command/mod.rs
new file mode 100644
index 00000000..7a61971e
--- /dev/null
+++ b/crates/synd_term/src/cli/command/mod.rs
@@ -0,0 +1,3 @@
+pub mod check;
+pub mod clean;
+pub mod export;
diff --git a/crates/synd_term/src/cli/mod.rs b/crates/synd_term/src/cli/mod.rs
index 38141a29..97982cf6 100644
--- a/crates/synd_term/src/cli/mod.rs
+++ b/crates/synd_term/src/cli/mod.rs
@@ -5,9 +5,7 @@ use url::Url;
 
 use crate::{config, ui::theme};
 
-mod check;
-mod clean;
-mod export;
+mod command;
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug, clap::ValueEnum)]
 pub enum Palette {
@@ -102,9 +100,9 @@ pub struct GithubOptions {
 #[derive(Subcommand, Debug)]
 pub enum Command {
     #[command(alias = "clear")]
-    Clean(clean::CleanCommand),
-    Check(check::CheckCommand),
-    Export(export::ExportCommand),
+    Clean(command::clean::CleanCommand),
+    Check(command::check::CheckCommand),
+    Export(command::export::ExportCommand),
 }
 
 pub fn parse() -> Args {
diff --git a/crates/synd_term/src/filesystem.rs b/crates/synd_term/src/filesystem.rs
new file mode 100644
index 00000000..425f94b5
--- /dev/null
+++ b/crates/synd_term/src/filesystem.rs
@@ -0,0 +1,53 @@
+use std::{io, path::Path};
+
+pub trait FileSystem {
+    fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
+}
+
+pub mod fsimpl {
+    #[derive(Debug, Clone)]
+    pub struct FileSystem {}
+
+    impl FileSystem {
+        pub fn new() -> Self {
+            Self {}
+        }
+    }
+
+    impl super::FileSystem for FileSystem {
+        fn remove_file<P: AsRef<std::path::Path>>(&self, path: P) -> std::io::Result<()> {
+            std::fs::remove_file(path)
+        }
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod mock {
+    use std::{collections::HashMap, io, path::PathBuf};
+
+    #[derive(Default, Clone)]
+    pub(crate) struct MockFileSystem {
+        remove_errors: HashMap<PathBuf, io::ErrorKind>,
+    }
+
+    impl MockFileSystem {
+        pub(crate) fn with_remove_errors(
+            mut self,
+            path: impl Into<PathBuf>,
+            err: io::ErrorKind,
+        ) -> Self {
+            self.remove_errors.insert(path.into(), err);
+            self
+        }
+    }
+
+    impl super::FileSystem for MockFileSystem {
+        fn remove_file<P: AsRef<std::path::Path>>(&self, path: P) -> io::Result<()> {
+            let path = path.as_ref();
+            match self.remove_errors.get(path) {
+                Some(err) => Err(io::Error::from(*err)),
+                None => Ok(()),
+            }
+        }
+    }
+}
diff --git a/crates/synd_term/src/lib.rs b/crates/synd_term/src/lib.rs
index a172e719..d4d07ca5 100644
--- a/crates/synd_term/src/lib.rs
+++ b/crates/synd_term/src/lib.rs
@@ -7,6 +7,7 @@ pub mod cli;
 pub mod client;
 pub(crate) mod command;
 pub mod config;
+pub mod filesystem;
 pub mod interact;
 pub mod job;
 pub mod keymap;
diff --git a/crates/synd_term/src/main.rs b/crates/synd_term/src/main.rs
index ca9bf236..2d4692cb 100644
--- a/crates/synd_term/src/main.rs
+++ b/crates/synd_term/src/main.rs
@@ -1,4 +1,4 @@
-use std::{future, path::PathBuf, time::Duration};
+use std::{future, path::PathBuf, process::ExitCode, time::Duration};
 
 use anyhow::Context as _;
 use futures_util::TryFutureExt;
@@ -7,6 +7,7 @@ use synd_term::{
     cli::{self, ApiOptions, Args, FeedOptions, GithubOptions, Palette},
     client::{github::GithubClient, Client},
     config::{self, Categories},
+    filesystem::fsimpl::FileSystem,
     terminal::{self, Terminal},
     ui::theme::Theme,
 };
@@ -101,7 +102,7 @@ fn build_app(
 }
 
 #[tokio::main]
-async fn main() {
+async fn main() -> ExitCode {
     let Args {
         api: ApiOptions {
             endpoint,
@@ -121,13 +122,11 @@ async fn main() {
     let _guard = init_tracing(log).unwrap();
 
     if let Some(command) = command {
-        let exit_code = match command {
-            cli::Command::Clean(clean) => clean.run(),
+        return match command {
+            cli::Command::Clean(clean) => clean.run(&FileSystem::new()),
             cli::Command::Check(check) => check.run(endpoint).await,
             cli::Command::Export(export) => export.run(endpoint).await,
         };
-
-        std::process::exit(exit_code);
     };
 
     let mut event_stream = terminal::event_stream();
@@ -148,6 +147,8 @@ async fn main() {
     .await
     {
         error!("{err:?}");
-        std::process::exit(1);
+        ExitCode::FAILURE
+    } else {
+        ExitCode::SUCCESS
     }
 }
diff --git a/justfile b/justfile
index 4b9be559..1e9b2956 100644
--- a/justfile
+++ b/justfile
@@ -83,7 +83,7 @@ review:
 coverage *flags:
     nix run nixpkgs#cargo-llvm-cov -- llvm-cov nextest \
         --all-features --open \
-        --ignore-filename-regex '(integration_backend.rs|client/generated/.*.rs)' \
+        --ignore-filename-regex '(integration_backend.rs|client/generated/.*.rs|synd_ebpf_task/src/.*.rs)' \
         {{ flags }}
 
 [macos]