make separate process spawn function with error types to avoid code duplication

src/dl.rs

@@ -1,2 +1,3 @@
-pub mod yt_dlp;
 pub mod ffmpeg;
+mod spawn;
+pub mod yt_dlp;

src/dl/ffmpeg.rs

@@ -1,50 +1,27 @@
-use core::fmt;
-use std::{path::Path, str::Utf8Error};
-use tokio::process::Command;
-
-pub enum FFMpegError {
-    CommandError(std::io::Error),
-    UtfError(Utf8Error),
-    ErrorMessage(String)
-}
-
-impl From<std::io::Error> for FFMpegError {
-    fn from(value: std::io::Error) -> Self {
-        Self::CommandError(value)
-    }
-}
-
-impl From<Utf8Error> for FFMpegError {
-    fn from(value: Utf8Error) -> Self {
-        Self::UtfError(value)
-    }
-}
-
-impl fmt::Display for FFMpegError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        use FFMpegError as FE;
-        match self {
-            FE::CommandError(e) => write!(f, "Command::new - {}", e),
-            FE::UtfError(_) => write!(f, "Error while decoding UTF8"),
-            FE::ErrorMessage(msg) => write!(f, "ffmpeg error - {}", msg)
-        }
-    }
-}
+use super::spawn::{spawn, SpawnError};
 
 pub struct FFMpeg {}
 
 impl FFMpeg {
-    pub async fn convert_to_mp3(input_path: &str, output_path: &str, bitrate: u16) -> Result<(), FFMpegError> {
-        let output = Command::new("ffmpeg")
-            .args(["-i", input_path, "-codec:a", "libmp3lame", "-b:a", "32k", output_path])
-            .output()
+    pub async fn convert_to_mp3(
+        input_path: &str,
+        output_path: &str,
+        bitrate: u16,
+    ) -> Result<(), SpawnError> {
+        let output = spawn(
+            "ffmpeg",
+            [
+                "-i",
+                input_path,
+                "-codec:a",
+                "libmp3lame",
+                "-b:a",
+                "32k",
+                output_path,
+            ],
+        )
         .await?;
 
-        if !output.status.success() {
-            let message = std::str::from_utf8(&output.stderr)?;
-            return Err(FFMpegError::ErrorMessage(message.to_string()));
-        }
-        
         Ok(())
     }
 }

src/dl/spawn.rs

@@ -0,0 +1,50 @@
+use core::fmt;
+use std::ffi::OsStr;
+use std::process::Output;
+use std::str::Utf8Error;
+use tokio::process::Command;
+
+#[derive(Debug)]
+pub enum SpawnError {
+    CommandError(std::io::Error),
+    UtfError(Utf8Error),
+    ErrorMessage(String),
+}
+
+impl From<std::io::Error> for SpawnError {
+    fn from(value: std::io::Error) -> Self {
+        Self::CommandError(value)
+    }
+}
+
+impl From<Utf8Error> for SpawnError {
+    fn from(value: Utf8Error) -> Self {
+        Self::UtfError(value)
+    }
+}
+
+impl fmt::Display for SpawnError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use SpawnError as FE;
+        match self {
+            FE::CommandError(e) => write!(f, "Command::new - {}", e),
+            FE::UtfError(_) => write!(f, "Error while decoding UTF8"),
+            FE::ErrorMessage(msg) => write!(f, "ffmpeg error - {}", msg),
+        }
+    }
+}
+
+pub async fn spawn<I, S>(program: &str, args: I) -> Result<Output, SpawnError>
+where
+    I: IntoIterator<Item = S>,
+    S: AsRef<OsStr>,
+{
+    let output = Command::new(program).args(args).output().await?;
+
+    if !output.status.success() {
+        let message = std::str::from_utf8(&output.stderr)?;
+        return Err(SpawnError::ErrorMessage(message.to_string()));
+    }
+
+    Ok(output)
+}

src/dl/yt_dlp.rs

@@ -1,9 +1,8 @@
+use super::spawn::{spawn, SpawnError};
 use core::fmt;
+use ordered_float::OrderedFloat;
 use serde::Deserialize;
 use serde_json;
-use std::str::Utf8Error;
-use tokio::process::Command;
-use ordered_float::OrderedFloat;
 
 #[derive(Deserialize, Debug)]
 pub struct YtDlpFormat {
@@ -27,7 +26,7 @@ struct VideoFormat<'a> {
 
 struct AudioFormat<'a> {
     pub format: &'a YtDlpFormat,
-    pub abr: f32
+    pub abr: f32,
 }
 
 impl YtDlpFormat {
@@ -114,7 +113,12 @@ impl YtDlpInfo {
         let format = self
             .formats
             .iter()
-            .filter_map(|f| Some(AudioFormat { format: f, abr: f.abr? }))
+            .filter_map(|f| {
+                Some(AudioFormat {
+                    format: f,
+                    abr: f.abr?,
+                })
+            })
             .max_by_key(|f| OrderedFloat(f.abr));
 
         match format {
@@ -126,21 +130,13 @@ impl YtDlpInfo {
 
 #[derive(Debug)]
 pub enum YtDlpError {
-    CommandError(std::io::Error),
-    UtfError(Utf8Error),
-    ErrorMessage(String),
+    SpawnError(SpawnError),
     JsonError,
 }
 
-impl From<std::io::Error> for YtDlpError {
-    fn from(value: std::io::Error) -> Self {
-        Self::CommandError(value)
-    }
-}
-
-impl From<Utf8Error> for YtDlpError {
-    fn from(value: Utf8Error) -> Self {
-        Self::UtfError(value)
+impl From<SpawnError> for YtDlpError {
+    fn from(value: SpawnError) -> Self {
+        Self::SpawnError(value)
     }
 }
 
@@ -154,9 +150,7 @@ impl fmt::Display for YtDlpError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use YtDlpError as YTE;
         match self {
-            YTE::CommandError(e) => write!(f, "Command::new - {}", e),
-            YTE::UtfError(_) => write!(f, "Error while decoding UTF8"),
-            YTE::ErrorMessage(msg) => write!(f, "yt-dlp error - {}", msg),
+            YTE::SpawnError(e) => write!(f, "{}", e),
             YTE::JsonError => write!(f, "json parsing error"),
         }
     }
@@ -166,15 +160,7 @@ pub struct YtDlp {}
 
 impl YtDlp {
     pub async fn load_info(url: &str) -> Result<YtDlpInfo, YtDlpError> {
-        let output = Command::new("python")
-            .args(["-m", "yt_dlp", url, "-j"])
-            .output()
-            .await?;
-
-        if !output.status.success() {
-            let message = std::str::from_utf8(&output.stderr)?;
-            return Err(YtDlpError::ErrorMessage(message.to_string()));
-        }
+        let output = spawn("python", ["-m", "yt_dlp", url, "-j"]).await?;
 
         Ok(YtDlpInfo::parse(&output.stdout)?)
     }