app: improve config loading and merging

crates/app/src/config/cli.rs

@@ -6,7 +6,7 @@ use clap::Parser;
 pub(crate) struct Args {
     /// Read this config file.
     #[arg(short, long)]
-    pub config_file: Option<PathBuf>,
+    pub config_path: Option<PathBuf>,
     #[arg(long, env = "NO_STARTUP_MESSAGE", default_value = "false")]
     pub no_startup_message: bool,
 }

crates/app/src/config/config_file.rs

@@ -1,12 +1,11 @@
 use std::{
     fs,
     path::{Path, PathBuf},
-    process,
 };
 
 use serde::{Deserialize, Serialize};
 
-use crate::error_reporting::{report_serde_json_err, report_serde_ron_err};
+use super::error::ConfigError;
 
 #[derive(Debug, Serialize, Deserialize)]
 pub struct Configs {
@@ -17,59 +16,37 @@ pub struct Configs {
 }
 
 /// what the fuck serde why do i need this
-pub(crate) fn default_example_value() -> i32 {
+fn default_example_value() -> i32 {
     43
 }
 
-pub(crate) fn default_no_startup_msg() -> bool {
+fn default_no_startup_msg() -> bool {
     false
 }
 
+pub(super) fn find_config_file() -> Result<PathBuf, ConfigError> {
+    let Some(config_path) = dirs::config_dir() else {
+        return Err(ConfigError::NoConfigDir);
+    };
+
+    let ron_path = config_path.with_file_name("config.ron");
+    let json_path = config_path.with_file_name("config.json");
+
+    if Path::new(&ron_path).exists() {
+        Ok(ron_path)
+    } else if Path::new(&json_path).exists() {
+        Ok(json_path)
+    } else {
+        Err(ConfigError::NoConfigFileFound)
+    }
+}
+
 impl Configs {
-    pub fn read(custom_path: Option<PathBuf>) -> Self {
-        use owo_colors::OwoColorize;
-        let p = match custom_path {
-            Some(p) => p,
-            None => {
-                let config_path = dirs::config_dir().expect("config dir should exist");
-
-                let ron_path = config_path.with_file_name("config.ron");
-                let json_path = config_path.with_file_name("config.json");
-
-                if Path::new(&ron_path).exists() {
-                    ron_path
-                } else if Path::new(&json_path).exists() {
-                    json_path
-                } else {
-                    eprintln!("{}: couldn't find config file", "Fatal error".red());
-                    process::exit(1)
-                }
-            }
-        };
-
+    pub fn read(p: PathBuf) -> Result<Self, ConfigError> {
         match p.extension().map(|v| v.to_str().unwrap()) {
-            Some("ron") => Self::read_json(&fs::read_to_string(p).unwrap()),
-            Some("json") => Self::read_ron(&fs::read_to_string(p).unwrap()),
-            None | Some(_) => {
-                eprintln!(
-                    "{}: couldn't determine config file type",
-                    "Fatal error".red()
-                );
-                process::exit(1)
-            }
-        }
-    }
-    pub fn read_json(config_text: &str) -> Configs {
-        match serde_json::from_str(config_text) {
-            Ok(c) => c,
-            Err(e) => report_serde_json_err(config_text, e),
-        }
-    }
-
-    pub fn read_ron(config_text: &str) -> Configs {
-        match ron::from_str(config_text) {
-            Ok(c) => c,
-            Err(e) => report_serde_ron_err(config_text, e),
+            Some("ron") => Ok(serde_json::from_str(&fs::read_to_string(p)?)?),
+            Some("json") => Ok(ron::from_str(&fs::read_to_string(p)?)?),
+            e => Err(ConfigError::UnknownExtension(e.map(|v| v.to_owned()))),
         }
     }
 }