Use own Error type

src/error.rs

@@ -0,0 +1,15 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("invalid regex {0}")]
+    Regex(#[from] regex::Error),
+    #[error("{0}")]
+    File(#[from] std::io::Error),
+    #[error("failed to move file: {0}")]
+    TempfilePersist(#[from] tempfile::PersistError),
+    #[error("file doesn't have parent path: {0}")]
+    InvalidPath(std::path::PathBuf),
+}
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;

src/input.rs

@@ -1,4 +1,4 @@
-use crate::{err, utils, Result};
+use crate::{utils, Error, Result};
 use regex::bytes::Regex;
 use std::{fs::File, io::prelude::*};
 
@@ -94,10 +94,10 @@ impl Replacer {
         let mmap_source = unsafe { Mmap::map(&source)? };
         let replaced = self.replace(&mmap_source);
 
-        let target =
-            tempfile::NamedTempFile::new_in(path.parent().ok_or_else(
-                || err!("Invalid path given: {}", path.display()),
-            )?)?;
+        let target = tempfile::NamedTempFile::new_in(
+            path.parent()
+                .ok_or_else(|| Error::InvalidPath(path.to_path_buf()))?,
+        )?;
         let file = target.as_file();
         file.set_len(replaced.len() as u64)?;
         file.set_permissions(meta.permissions())?;

src/main.rs

@@ -1,9 +1,10 @@
 mod app;
+mod error;
 mod input;
 pub(crate) mod utils;
 
 pub(crate) use self::input::{Replacer, Source};
-pub(crate) use anyhow::{anyhow as err, Result};
+pub(crate) use error::{Error, Result};
 
 fn main() -> Result<()> {
     use structopt::StructOpt;