refactor(rust): cleanup path handling

- Avoids unnecessary string allocation when tracing paths
- Replaces `mut path & path.push()` with `path.join()`
- Avoids unncessary cloning of paths where applicable
- Use `dunce` crate to remove `UNC` prefix
- Improve performance of resolving `~` by avoiding unnecessary string allocations
- Resolve `~`, `$Env:USERPROFILE` and `$HOME` consistenly between different code paths
- Use `PathBuf` instead of `String` for paths in CLI args

I may have missed a couple of places but I think I covered 90% of path handling in the codebase

komorebi-core/Cargo.toml

@@ -7,10 +7,12 @@ edition = "2021"
 
 [dependencies]
 clap = { version = "4", features = ["derive"] }
-color-eyre = "0.6"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 serde_yaml = "0.9"
 strum = { version = "0.25", features = ["derive"] }
 schemars = "0.8"
+color-eyre = { workspace = true }
 windows = { workspace = true }
+dunce = { workspace = true }
+dirs = { workspace = true }

komorebi-core/src/custom_layout.rs

@@ -3,9 +3,10 @@ use std::fs::File;
 use std::io::BufReader;
 use std::ops::Deref;
 use std::ops::DerefMut;
-use std::path::PathBuf;
+use std::path::Path;
 
 use color_eyre::eyre::anyhow;
+use color_eyre::eyre::bail;
 use color_eyre::Result;
 use schemars::JsonSchema;
 use serde::Deserialize;
@@ -31,23 +32,20 @@ impl DerefMut for CustomLayout {
 }
 
 impl CustomLayout {
-    pub fn from_path_buf(path: PathBuf) -> Result<Self> {
-        let invalid_filetype = anyhow!("custom layouts must be json or yaml files");
+    pub fn from_path<P: AsRef<Path>>(path: P) -> Result<Self> {
+        let path = path.as_ref();
         let layout: Self = match path.extension() {
-            Some(extension) => {
-                if extension == "yaml" || extension == "yml" {
-                    serde_yaml::from_reader(BufReader::new(File::open(path)?))?
-                } else if extension == "json" {
-                    serde_json::from_reader(BufReader::new(File::open(path)?))?
-                } else {
-                    return Err(invalid_filetype);
-                }
+            Some(extension) if extension == "yaml" || extension == "yml" => {
+                serde_json::from_reader(BufReader::new(File::open(path)?))?
             }
-            None => return Err(invalid_filetype),
+            Some(extension) if extension == "json" => {
+                serde_json::from_reader(BufReader::new(File::open(path)?))?
+            }
+            _ => return Err(anyhow!("custom layouts must be json or yaml files")),
         };
 
         if !layout.is_valid() {
-            return Err(anyhow!("the layout file provided was invalid"));
+            bail!("the layout file provided was invalid");
         }
 
         Ok(layout)

komorebi-core/src/lib.rs

@@ -1,10 +1,12 @@
 #![warn(clippy::all, clippy::nursery, clippy::pedantic)]
 #![allow(clippy::missing_errors_doc, clippy::use_self)]
 
+use std::path::Path;
 use std::path::PathBuf;
 use std::str::FromStr;
 
 use clap::ValueEnum;
+use color_eyre::eyre::anyhow;
 use color_eyre::Result;
 use schemars::JsonSchema;
 use serde::Deserialize;
@@ -298,3 +300,36 @@ impl Sizing {
         }
     }
 }
+
+pub fn resolve_home_path<P: AsRef<Path>>(path: P) -> Result<PathBuf> {
+    let mut resolved_path = PathBuf::new();
+    let mut resolved = false;
+    for c in path.as_ref().components() {
+        match c {
+            std::path::Component::Normal(c)
+                if (c == "~" || c == "$Env:USERPROFILE" || c == "$HOME") && !resolved =>
+            {
+                let home = dirs::home_dir().ok_or_else(|| anyhow!("there is no home directory"))?;
+
+                resolved_path.extend(home.components());
+                resolved = true;
+            }
+
+            _ => resolved_path.push(c),
+        }
+    }
+
+    let parent = resolved_path
+        .parent()
+        .ok_or_else(|| anyhow!("cannot parse parent directory"))?;
+
+    Ok(if parent.is_dir() {
+        let file = resolved_path
+            .components()
+            .last()
+            .ok_or_else(|| anyhow!("cannot parse filename"))?;
+        dunce::canonicalize(parent)?.join(file)
+    } else {
+        resolved_path
+    })
+}