Refactor filter command line option handling

Author: cknitt

rewatch/src/cli.rs

@@ -2,6 +2,11 @@ use std::{ffi::OsString, ops::Deref};
 
 use clap::{Args, Parser, Subcommand};
 use clap_verbosity_flag::InfoLevel;
+use regex::Regex;
+
+fn parse_regex(s: &str) -> Result<Regex, regex::Error> {
+    Regex::new(s)
+}
 
 /// ReScript - Fast, Simple, Fully Typed JavaScript from the Future
 #[derive(Parser, Debug)]
@@ -39,8 +44,8 @@ pub struct FilterArg {
     ///
     /// Filter allows for a regex to be supplied which will filter the files to be compiled. For
     /// instance, to filter out test files for compilation while doing feature work.
-    #[arg(short, long)]
-    pub filter: Option<String>,
+    #[arg(short, long, value_parser = parse_regex)]
+    pub filter: Option<Regex>,
 }
 
 #[derive(Args, Debug, Clone)]
@@ -187,7 +192,7 @@ impl Deref for FolderArg {
 }
 
 impl Deref for FilterArg {
-    type Target = Option<String>;
+    type Target = Option<Regex>;
 
     fn deref(&self) -> &Self::Target {
         &self.filter

rewatch/src/main.rs

@@ -1,7 +1,6 @@
 use anyhow::Result;
 use clap::Parser;
 use log::LevelFilter;
-use regex::Regex;
 use std::{io::Write, path::Path};
 
 use rewatch::{build, cli, cmd, lock, watcher};
@@ -31,13 +30,8 @@ fn main() -> Result<()> {
         cli::Command::Build(build_args) => {
             let _lock = get_lock(&build_args.folder);
 
-            let filter = build_args
-                .filter
-                .as_ref()
-                .map(|filter| Regex::new(&filter).expect("Could not parse regex"));
-
             match build::build(
-                &filter,
+                &build_args.filter,
                 Path::new(&build_args.folder as &str),
                 show_progress,
                 build_args.no_timing,
@@ -60,12 +54,8 @@ fn main() -> Result<()> {
         cli::Command::Watch(watch_args) => {
             let _lock = get_lock(&watch_args.folder);
 
-            let filter = watch_args
-                .filter
-                .as_ref()
-                .map(|filter| Regex::new(&filter).expect("Could not parse regex"));
             watcher::start(
-                &filter,
+                &watch_args.filter,
                 show_progress,
                 &watch_args.folder,
                 (*watch_args.after_build).clone(),