From 6c653e8e528c2248559cc7dccf62c61878fe9f85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fe=CC=81lix=20Saparelli?= <felix@passcod.name>
Date: Mon, 28 Oct 2019 18:55:39 +1300
Subject: [PATCH] Return owned Args from Handler instead of borrowed

---
 src/main.rs |  2 +-
 src/run.rs  | 22 ++++++++++++----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 7834023..b206983 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,5 +3,5 @@ extern crate watchexec;
 use watchexec::{cli, error, run};
 
 fn main() -> error::Result<()> {
-    run(cli::get_args()?)
+    run(&cli::get_args()?)
 }
diff --git a/src/run.rs b/src/run.rs
index c1bdb12..f2c5196 100644
--- a/src/run.rs
+++ b/src/run.rs
@@ -59,15 +59,18 @@ pub trait Handler {
     /// - `Ok(false)`: everything is fine but we should gracefully stop.
     fn on_update(&self, ops: &[PathOp]) -> Result<bool>;
 
-    /// Handler implementations must return a customized watchexec Args reference for use in the
-    /// calling watcher.
-    fn args(&self) -> &Args;
+    /// Called once by `watch` at the very start.
+    ///
+    /// Not called again; any changes will never be picked up.
+    ///
+    /// The `Args` instance should be created using `ArgsBuilder` rather than direct initialisation
+    /// to resist potential breaking changes (see semver policy on crate root).
+    fn args(&self) -> Args;
 }
 
 /// Starts watching, and calls a handler when something happens.
 ///
-/// Given an argument structure and a `Handler` type, starts the watcher
-/// loop (blocking until done).
+/// Given an argument structure and a `Handler` type, starts the watcher loop, blocking until done.
 pub fn watch<H>(handler: &H) -> Result<()>
 where
     H: Handler,
@@ -189,8 +192,8 @@ impl<'a> ExecHandler<'a> {
 }
 
 impl<'a> Handler for ExecHandler<'a> {
-    fn args(&self) -> &Args {
-        &self.args
+    fn args(&self) -> Args {
+        self.args.clone()
     }
 
     // Only returns Err() on lock poisoning.
@@ -252,9 +255,8 @@ impl<'a> Handler for ExecHandler<'a> {
     }
 }
 
-pub fn run(args: Args) -> Result<()> {
-    let handler = ExecHandler::new(&args)?;
-    watch(&handler)
+pub fn run(args: &Args) -> Result<()> {
+    watch(&ExecHandler::new(args)?)
 }
 
 fn wait_fs(rx: &Receiver<Event>, filter: &NotificationFilter, debounce: u64) -> Vec<PathOp> {