feat: readable toml parsing error (#854)

Previously, the yazi displayed the following error.
```
Backtrace omitted. Run with RUST_BACKTRACE=1 to display it.
Run with RUST_BACKTRACE=full to include source snippets.

The application panicked (crashed).
  called `Result::unwrap()` on an `Err` value: Error { inner: Error { inner: TomlError { message: "invalid key", raw: Some("{ mime = \"application/octet-stream\",\nuse = [ \"extract_zlib\", \"reveal\" ] }\n"), keys: [], span: Some(0..1) } } }
in yazi-config/src/preset.rs, line 42
thread: main
```

It now displays the following message instead:

```
Error: Loading "/home/solo/.config/yazi/yazi.toml"

Caused by:
    TOML parse error at line 1, column 1
      |
    1 | { mime = "application/octet-stream",
      | ^
    invalid key
```

For more information see issue GH-847.

---------

Co-authored-by: sxyazi <sxyazi@gmail.com>

yazi-config/src/lib.rs

@@ -47,11 +47,11 @@ pub static INPUT: RoCell<popup::Input> = RoCell::new();
 pub static SELECT: RoCell<popup::Select> = RoCell::new();
 pub static WHICH: RoCell<which::Which> = RoCell::new();
 
-pub fn init() {
+pub fn init() -> anyhow::Result<()> {
 	let config_dir = Xdg::config_dir();
-	MERGED_YAZI.init(Preset::yazi(&config_dir));
-	MERGED_KEYMAP.init(Preset::keymap(&config_dir));
-	MERGED_THEME.init(Preset::theme(&config_dir));
+	MERGED_YAZI.init(Preset::yazi(&config_dir)?);
+	MERGED_KEYMAP.init(Preset::keymap(&config_dir)?);
+	MERGED_THEME.init(Preset::theme(&config_dir)?);
 
 	LAYOUT.with(Default::default);
 
@@ -81,4 +81,5 @@ Add `disable_exec_warn = true` to your `yazi.toml` under `[headsup]` to suppress
 "#
 		);
 	}
+	Ok(())
 }

yazi-config/src/preset.rs

@@ -1,6 +1,6 @@
 use std::{mem, path::{Path, PathBuf}};
 
-use anyhow::Context;
+use anyhow::{anyhow, Context, Result};
 use toml::{Table, Value};
 
 use crate::theme::Flavor;
@@ -8,28 +8,27 @@ use crate::theme::Flavor;
 pub(crate) struct Preset;
 
 impl Preset {
-	pub(crate) fn yazi(p: &Path) -> String {
+	pub(crate) fn yazi(p: &Path) -> Result<String> {
 		Self::merge_path(p.join("yazi.toml"), include_str!("../preset/yazi.toml"))
 	}
 
-	pub(crate) fn keymap(p: &Path) -> String {
+	pub(crate) fn keymap(p: &Path) -> Result<String> {
 		Self::merge_path(p.join("keymap.toml"), include_str!("../preset/keymap.toml"))
 	}
 
-	pub(crate) fn theme(p: &Path) -> String {
+	pub(crate) fn theme(p: &Path) -> Result<String> {
 		let Ok(user) = std::fs::read_to_string(p.join("theme.toml")) else {
-			return include_str!("../preset/theme.toml").to_owned();
+			return Ok(include_str!("../preset/theme.toml").to_owned());
 		};
 		let Some(use_) = Flavor::parse_use(&user) else {
 			return Self::merge_str(&user, include_str!("../preset/theme.toml"));
 		};
 
-		let p = p.join(format!("flavors/{}.yazi/flavor.toml", use_));
-		let flavor = std::fs::read_to_string(&p)
-			.with_context(|| format!("Failed to load flavor {:?}", p))
-			.unwrap();
+		let p = p.join(format!("flavors/{use_}.yazi/flavor.toml"));
+		let flavor =
+			std::fs::read_to_string(&p).with_context(|| anyhow!("Failed to load flavor {p:?}"))?;
 
-		Self::merge_str(&user, &Self::merge_str(&flavor, include_str!("../preset/theme.toml")))
+		Self::merge_str(&user, &Self::merge_str(&flavor, include_str!("../preset/theme.toml"))?)
 	}
 
 	#[inline]
@@ -38,21 +37,21 @@ impl Preset {
 	}
 
 	#[inline]
-	pub(crate) fn merge_str(user: &str, base: &str) -> String {
-		let mut t = user.parse().unwrap();
-		Self::merge(&mut t, base.parse().unwrap(), 2);
+	pub(crate) fn merge_str(user: &str, base: &str) -> Result<String> {
+		let mut t = user.parse()?;
+		Self::merge(&mut t, base.parse()?, 2);
 
-		t.to_string()
+		Ok(t.to_string())
 	}
 
 	#[inline]
-	fn merge_path(user: PathBuf, base: &str) -> String {
-		let s = std::fs::read_to_string(user).unwrap_or_default();
+	fn merge_path(user: PathBuf, base: &str) -> Result<String> {
+		let s = std::fs::read_to_string(&user).unwrap_or_default();
 		if s.is_empty() {
-			return base.to_string();
+			return Ok(base.to_string());
 		}
 
-		Self::merge_str(&s, base)
+		Self::merge_str(&s, base).with_context(|| anyhow!("Loading {user:?}"))
 	}
 
 	fn merge(a: &mut Table, b: Table, max: u8) {

yazi-fm/src/main.rs

@@ -39,7 +39,7 @@ async fn main() -> anyhow::Result<()> {
 
 	_ = fdlimit::raise_fd_limit();
 
-	yazi_config::init();
+	yazi_config::init()?;
 
 	yazi_adaptor::init();