From a00912f17f829fb82d33b2d813289e4632a3d66f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fe=CC=81lix=20Saparelli?= <felix@passcod.name>
Date: Wed, 29 Dec 2021 19:29:45 +1300
Subject: [PATCH] Implement --no-meta for default filterer

---
 cli/src/args.rs             | 10 ++++-----
 cli/src/filterer/globset.rs | 42 ++++++++++++++++++++++++++++++++-----
 2 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/cli/src/args.rs b/cli/src/args.rs
index bf39af4..744757f 100644
--- a/cli/src/args.rs
+++ b/cli/src/args.rs
@@ -94,11 +94,11 @@ pub fn get_args(tagged_filterer: bool) -> Result<ArgMatches<'static>> {
 			.help("Print events that trigger actions")
 			.long("print-events")
 			.alias("changes-only")) // --changes-only is deprecated (remove at v2)
-		.arg(Arg::with_name("no-vcs-ignore") // TODO
+		.arg(Arg::with_name("no-vcs-ignore")
 			.help_heading(Some(OPTSET_FILTERING))
 			.help("Skip auto-loading of VCS (Git, etc) ignore files")
 			.long("no-vcs-ignore"))
-		.arg(Arg::with_name("no-project-ignore") // TODO
+		.arg(Arg::with_name("no-project-ignore")
 			.help_heading(Some(OPTSET_FILTERING))
 			.help("Skip auto-loading of project ignore files (.gitignore, .ignore, etc)")
 			.long("no-ignore"))
@@ -106,7 +106,7 @@ pub fn get_args(tagged_filterer: bool) -> Result<ArgMatches<'static>> {
 			.help_heading(Some(OPTSET_FILTERING))
 			.help("Skip auto-ignoring of commonly ignored globs")
 			.long("no-default-ignore"))
-		.arg(Arg::with_name("no-global-ignore") // TODO
+		.arg(Arg::with_name("no-global-ignore")
 			.help_heading(Some(OPTSET_FILTERING))
 			.help("Skip auto-loading of global or environment-wide ignore files")
 			.long("no-global-ignore"))
@@ -186,7 +186,7 @@ pub fn get_args(tagged_filterer: bool) -> Result<ArgMatches<'static>> {
 				.long("no-default-filters"),
 		)
 		.arg(
-			Arg::with_name("no-meta") // TODO
+			Arg::with_name("no-meta")
 				.help_heading(Some(OPTSET_FILTERING))
 				.help("Ignore metadata changes (equivalent of `-f 'kind*!Modify(Metadata(*))'`)")
 				.long("no-meta"),
@@ -223,7 +223,7 @@ pub fn get_args(tagged_filterer: bool) -> Result<ArgMatches<'static>> {
 				.value_name("pattern"),
 		)
 		.arg(
-			Arg::with_name("no-meta") // TODO
+			Arg::with_name("no-meta")
 				.help_heading(Some(OPTSET_FILTERING))
 				.help("Ignore metadata changes")
 				.long("no-meta"),
diff --git a/cli/src/filterer/globset.rs b/cli/src/filterer/globset.rs
index 666dd71..38ca25c 100644
--- a/cli/src/filterer/globset.rs
+++ b/cli/src/filterer/globset.rs
@@ -5,9 +5,16 @@ use std::{
 
 use clap::ArgMatches;
 use miette::{IntoDiagnostic, Result};
-use watchexec::filter::globset::GlobsetFilterer;
+use watchexec::{
+	error::RuntimeError,
+	event::{
+		filekind::{FileEventKind, ModifyKind},
+		Event, Tag,
+	},
+	filter::{globset::GlobsetFilterer, Filterer},
+};
 
-pub async fn globset(args: &ArgMatches<'static>) -> Result<Arc<GlobsetFilterer>> {
+pub async fn globset(args: &ArgMatches<'static>) -> Result<Arc<WatchexecFilterer>> {
 	let (project_origin, workdir) = super::common::dirs(args).await?;
 	let ignorefiles = super::common::ignores(args, &project_origin).await?;
 
@@ -33,9 +40,34 @@ pub async fn globset(args: &ArgMatches<'static>) -> Result<Arc<GlobsetFilterer>>
 		.map(|s| s.split(b','))
 		.flatten();
 
-	Ok(Arc::new(
-		GlobsetFilterer::new(project_origin, filters, ignores, exts).into_diagnostic()?,
-	))
+	Ok(Arc::new(WatchexecFilterer {
+		inner: GlobsetFilterer::new(project_origin, filters, ignores, exts).into_diagnostic()?,
+		no_meta: args.is_present("no-meta"),
+	}))
+}
+
+/// A custom filterer that combines the library's Globset filterer and a switch for --no-meta
+#[derive(Debug)]
+pub struct WatchexecFilterer {
+	inner: GlobsetFilterer,
+	no_meta: bool,
+}
+
+impl Filterer for WatchexecFilterer {
+	fn check_event(&self, event: &Event) -> Result<bool, RuntimeError> {
+		let is_meta = event.tags.iter().any(|tag| {
+			matches!(
+				tag,
+				Tag::FileEventKind(FileEventKind::Modify(ModifyKind::Metadata(_)))
+			)
+		});
+
+		if self.no_meta && is_meta {
+			Ok(false)
+		} else {
+			self.inner.check_event(event)
+		}
+	}
 }
 
 trait OsStringSplit {