Switch to storing a path to the config file instead of a path to the root directory.

src/config/full.rs

@@ -1,3 +1,4 @@
+use std::path::Path;
 use std::path::PathBuf;
 use tokio::fs::File;
 use tokio::io::AsyncWriteExt;
@@ -7,26 +8,40 @@ use super::raw::RawConfig;
 /// This is the config struct used by most of the code, which is an interpreted version of the RawConfig struct which is the raw disk-representation of the config.
 pub(crate) struct Config {
     raw: RawConfig,
-    root_dir: PathBuf,
+    config_path: PathBuf,
 }
 
 impl Config {
-    pub(crate) fn new<P: Into<PathBuf>>(root_dir: P) -> Result<Config, Box<dyn std::error::Error>> {
+    pub(crate) fn new<P: AsRef<Path>>(root_dir: P) -> Result<Config, Box<dyn std::error::Error>> {
+        fn inner(root_dir: &Path) -> Result<Config, Box<dyn std::error::Error>> {
+            let file_path = root_dir.join("writer.toml");
             Ok(Config {
                 raw: RawConfig::default(),
-            root_dir: root_dir.into(),
+                config_path: file_path,
             })
         }
+        inner(root_dir.as_ref())
+    }
+
+    pub(crate) async fn load_from_file<P: Into<PathBuf>>(
+        path: P,
+    ) -> Result<Config, Box<dyn std::error::Error>> {
+        async fn inner(path: PathBuf) -> Result<Config, Box<dyn std::error::Error>> {
+            let contents = tokio::fs::read_to_string(&path).await?;
+            let parsed_contents: RawConfig = toml::from_str(contents.as_str())?;
+            Ok(Config {
+                raw: parsed_contents,
+                config_path: path,
+            })
+        }
+        inner(path.into()).await
+    }
 
     pub(crate) async fn write_to_disk(&self) -> Result<(), Box<dyn std::error::Error>> {
-        let mut config_file = File::create(self.get_path_to_config_file()).await?;
+        let mut config_file = File::create(&self.config_path).await?;
         config_file
             .write_all(toml::to_string(&self.raw)?.as_bytes())
             .await?;
         Ok(())
     }
-
-    pub(crate) fn get_path_to_config_file(&self) -> PathBuf {
-        self.root_dir.join("writer.toml")
-    }
 }