fix: panic if default config also doesn't exist

src/config.rs

@@ -28,7 +28,6 @@ fn deserialize(content: &str) -> Result<Config, DigsError> {
 }
 
 pub fn get(path: &Path) -> Result<Config, DigsError> {
-    // path must be exists. unwrap is safe here.
-    let file_content = fs::read_to_string(path).unwrap();
+    let file_content = fs::read_to_string(path)?;
     deserialize(&file_content)
 }

src/error.rs

@@ -26,4 +26,8 @@ pub enum DigsError {
     // All cases from trust-dns
     #[error("Error: {0:?}")]
     ForeignError(#[from] ClientError),
+
+    // All cases of `std::io::Error`.
+    #[error(transparent)]
+    IOError(#[from] std::io::Error),
 }

src/main.rs

@@ -24,7 +24,7 @@ fn run() -> Result<()> {
     // get config file
     let config_path: PathBuf = match matches.value_of("config") {
         Some(path) => utils::is_exist(path)?,
-        None => "digs.toml".into(),
+        None => utils::is_exist("digs.toml".into())?,
     };
     let config = config::get(&config_path)?;
 

tests/integration_test.rs

@@ -11,6 +11,15 @@ fn help() {
         .stdout(predicate::str::contains("digs \u{25cf} dig many at once"));
 }
 
+#[test]
+fn default_config_not_found() {
+    let mut cmd = Command::cargo_bin("digs").unwrap();
+    cmd.arg("example.net").arg("-f").arg("file/doesnt/exist");
+    cmd.assert()
+        .failure()
+        .stderr(predicate::str::contains("No such file"));
+}
+
 #[test]
 fn config_not_found() {
     let mut cmd = Command::cargo_bin("digs").unwrap();