fix: avoid all panics with proper error handling

Make sure all the `unwrap()` is safe and has proper error handling

README.md

@@ -20,6 +20,7 @@ dig many at once.
 ## Features
 
 - Prevent invalid input before querying. Such invalid records type or configuration.
+- No panics, good error handling.
 - [more faster](docs/benchmark.md) compared to previous `digs.py`.
 - Colourful output.
 - Cross-platform.

src/dns.rs

@@ -59,11 +59,11 @@ fn get_address(nameserver: &str) -> Result<std::net::SocketAddr, DigsError> {
 
 pub fn query(domain: &str, rtype: RTypes, nameserver: &str) -> Result<DnsResponse, DigsError> {
     let address = get_address(nameserver)?;
-    let conn = UdpClientConnection::new(address).unwrap();
+    let conn = UdpClientConnection::new(address)?;
     let client = SyncClient::new(conn);
 
     let rtype = get_rtype(rtype);
-    let name = Name::from_str(&format!("{}.", domain)).unwrap();
+    let name = Name::from_str(&format!("{}.", domain))?;
     let response = client.query(&name, DNSClass::IN, rtype);
     match response {
         Ok(resp) => Ok(resp),

src/error.rs

@@ -4,6 +4,7 @@ use std::path::PathBuf;
 
 use thiserror::Error;
 use trust_dns_client::error::ClientError;
+use trust_dns_client::proto::error::ProtoError;
 
 /// all possible errors returned by the app.
 #[derive(Error, Debug)]
@@ -30,4 +31,8 @@ pub enum DigsError {
     // All cases of `std::io::Error`.
     #[error(transparent)]
     IOError(#[from] std::io::Error),
+
+    // All cases of `trust_dns_proto::error::ProtoError`
+    #[error(transparent)]
+    Pro(#[from] ProtoError),
 }

src/main.rs

@@ -19,6 +19,7 @@ fn run() -> Result<()> {
     let domain = utils::is_domain(matches.value_of("domain").unwrap())?;
 
     // get rtype
+    // must be present. unwrap safe here
     let rtype = matches.value_of_t("rtype").unwrap();
 
     // get config file

src/utils.rs

@@ -2,8 +2,8 @@ use std::path::{Path, PathBuf};
 
 use crate::error::DigsError;
 
-pub fn current_dir() -> PathBuf {
-    std::env::current_dir().unwrap()
+pub fn current_dir() -> Result<PathBuf, DigsError> {
+    Ok(std::env::current_dir()?)
 }
 
 /// # Errors