Better TOML parsing error message (#1332)

The error handling for config loading was pretty poor.
That's because we didn't use the correct syntax to show the entire context with `anhow`.
See ["Display representations"](https://docs.rs/anyhow/latest/anyhow/struct.Error.html#display-representations).

lychee-bin/src/main.rs

@@ -63,7 +63,7 @@ use std::io::{self, BufRead, BufReader, ErrorKind, Write};
 use std::path::PathBuf;
 use std::sync::Arc;
 
-use anyhow::{Context, Error, Result};
+use anyhow::{bail, Context, Error, Result};
 use clap::Parser;
 use color::YELLOW;
 use commands::CommandParams;
@@ -159,8 +159,10 @@ fn load_config() -> Result<LycheeOptions> {
         match Config::load_from_file(config_file) {
             Ok(c) => opts.config.merge(c),
             Err(e) => {
-                error!("Error while loading config file {:?}: {}", config_file, e);
-                std::process::exit(ExitCode::ConfigFile as i32);
+                bail!(
+                    "Cannot load configuration file `{}`: {e:?}",
+                    config_file.display()
+                );
             }
         }
     } else {
@@ -253,7 +255,13 @@ fn load_cache(cfg: &Config) -> Option<Cache> {
 fn run_main() -> Result<i32> {
     use std::process::exit;
 
-    let opts = load_config()?;
+    let opts = match load_config() {
+        Ok(opts) => opts,
+        Err(e) => {
+            error!("Error while loading config: {e}");
+            exit(ExitCode::ConfigFile as i32);
+        }
+    };
 
     let runtime = match opts.config.threads {
         Some(threads) => {

lychee-bin/src/options.rs

@@ -408,8 +408,7 @@ impl Config {
     pub(crate) fn load_from_file(path: &Path) -> Result<Config> {
         // Read configuration file
         let contents = fs::read_to_string(path)?;
-        toml::from_str(&contents)
-            .map_err(|err| anyhow::anyhow!("Failed to parse configuration file: {}", err))
+        toml::from_str(&contents).with_context(|| "Failed to parse configuration file")
     }
 
     /// Merge the configuration from TOML into the CLI configuration

lychee-bin/tests/cli.rs

@@ -12,7 +12,10 @@ mod cli {
     use assert_json_diff::assert_json_include;
     use http::StatusCode;
     use lychee_lib::{InputSource, ResponseBody};
-    use predicates::str::{contains, is_empty};
+    use predicates::{
+        prelude::predicate,
+        str::{contains, is_empty},
+    };
     use pretty_assertions::assert_eq;
     use regex::Regex;
     use serde::Serialize;
@@ -602,7 +605,11 @@ mod cli {
             .arg("-")
             .env_clear()
             .assert()
-            .failure();
+            .failure()
+            .stderr(predicate::str::contains("Cannot load configuration file"))
+            .stderr(predicate::str::contains("Failed to parse"))
+            .stderr(predicate::str::contains("TOML parse error"))
+            .stderr(predicate::str::contains("expected newline"));
     }
 
     #[tokio::test]

lychee-lib/src/types/input.rs

@@ -203,7 +203,7 @@ impl Input {
                 InputSource::FsPath(ref path) => {
                     if path.is_dir() {
                         for entry in WalkDir::new(path).skip_hidden(true)
-                        .process_read_dir(move |_, _, _, children| {
+                        .process_read_dir(move |_, _, (), children| {
                             children.retain(|child| {
                                 let Ok(entry) = child.as_ref() else { return true };