fix: allow relative paths in allowlist and blocklist

src/args.rs

@@ -3,7 +3,29 @@
 
 use std::path::PathBuf;
 
-use clap::Parser;
+use clap::{builder::{PathBufValueParser, TypedValueParser}, Parser};
+
+#[derive(Clone, Default)]
+struct AbsolutePathBufValueParser;
+
+impl TypedValueParser for AbsolutePathBufValueParser {
+    type Value = PathBuf;
+
+    fn parse_ref(
+        &self,
+        cmd: &clap::Command,
+        arg: Option<&clap::Arg>,
+        value: &std::ffi::OsStr,
+    ) -> Result<Self::Value, clap::Error> {
+        let pathbuf_parser = PathBufValueParser::new();
+        let v = pathbuf_parser.parse_ref(cmd, arg, value)?;
+
+        v.canonicalize().map_err(|e| clap::Error::raw(
+            clap::error::ErrorKind::Io,
+            e,
+        ))
+    }
+}
 
 /// A tool to clean up sysroots for Linux embedded devices to save storage space.
 #[derive(Parser, Debug)]
@@ -20,7 +42,7 @@ pub struct Args {
 
     /// An allowlist of files to keep, in .gitignore format.
     /// Note: this will take precedence over all other removal decisions.
-    #[arg(long)]
+    #[arg(long, value_parser = AbsolutePathBufValueParser::default())]
     pub allowlist: Option<PathBuf>,
 
     /// A blocklist of files to remove, in .gitignore format.
@@ -35,3 +57,4 @@ pub struct Args {
     /// The location of the sysroot to clean up
     pub sysroot_location: PathBuf,
 }
+