3 files changed, 30 insertions, 17 deletions
diff --git a/cli/tools/fmt.rs b/cli/tools/fmt.rs
index 0036436c1..883ebc45b 100644
--- a/cli/tools/fmt.rs
+++ b/cli/tools/fmt.rs
@@ -9,11 +9,13 @@
 
 use crate::colors;
 use crate::diff::diff;
+use crate::file_watcher;
 use crate::fs_util::{collect_files, is_supported_ext};
 use crate::text_encoding;
 use deno_core::error::generic_error;
 use deno_core::error::AnyError;
 use deno_core::futures;
+use deno_core::futures::FutureExt;
 use dprint_plugin_typescript as dprint;
 use std::fs;
 use std::io::stdin;
@@ -28,25 +30,37 @@ use std::sync::{Arc, Mutex};
 const BOM_CHAR: char = '\u{FEFF}';
 
 /// Format JavaScript/TypeScript files.
-///
-/// First argument and ignore supports globs, and if it is `None`
-/// then the current directory is recursively walked.
 pub async fn format(
   args: Vec<PathBuf>,
+  ignore: Vec<PathBuf>,
   check: bool,
-  exclude: Vec<PathBuf>,
+  watch: bool,
 ) -> Result<(), AnyError> {
-  if args.len() == 1 && args[0].to_string_lossy() == "-" {
-    return format_stdin(check);
-  }
-  // collect the files that are to be formatted
-  let target_files = collect_files(args, exclude, is_supported_ext)?;
-  let config = get_config();
-  if check {
-    check_source_files(config, target_files).await
+  let target_file_resolver = || {
+    // collect the files that are to be formatted
+    collect_files(&args, &ignore, is_supported_ext)
+  };
+
+  let operation = |paths: Vec<PathBuf>| {
+    let config = get_config();
+    async move {
+      if check {
+        check_source_files(config, paths).await?;
+      } else {
+        format_source_files(config, paths).await?;
+      }
+      Ok(())
+    }
+    .boxed_local()
+  };
+
+  if watch {
+    file_watcher::watch_func(target_file_resolver, operation, "Fmt").await?;
   } else {
-    format_source_files(config, target_files).await
+    operation(target_file_resolver()?).await?;
   }
+
+  Ok(())
 }
 
 async fn check_source_files(
@@ -166,7 +180,7 @@ async fn format_source_files(
 /// Format stdin and write result to stdout.
 /// Treats input as TypeScript.
 /// Compatible with `--check` flag.
-fn format_stdin(check: bool) -> Result<(), AnyError> {
+pub fn format_stdin(check: bool) -> Result<(), AnyError> {
   let mut source = String::new();
   if stdin().read_to_string(&mut source).is_err() {
     return Err(generic_error("Failed to read from stdin"));
diff --git a/cli/tools/lint.rs b/cli/tools/lint.rs
index f17709c8b..c40dcfd54 100644
--- a/cli/tools/lint.rs
+++ b/cli/tools/lint.rs
@@ -47,7 +47,7 @@ pub async fn lint_files(
   if args.len() == 1 && args[0].to_string_lossy() == "-" {
     return lint_stdin(json);
   }
-  let target_files = collect_files(args, ignore, is_supported_ext)?;
+  let target_files = collect_files(&args, &ignore, is_supported_ext)?;
   debug!("Found {} files", target_files.len());
   let target_files_len = target_files.len();
 
diff --git a/cli/tools/test_runner.rs b/cli/tools/test_runner.rs
index 599a95059..64cff7e0f 100644
--- a/cli/tools/test_runner.rs
+++ b/cli/tools/test_runner.rs
@@ -44,8 +44,7 @@ pub fn prepare_test_modules_urls(
   for path in include_paths {
     let p = fs_util::normalize_path(&root_path.join(path));
     if p.is_dir() {
-      let test_files =
-        crate::fs_util::collect_files(vec![p], vec![], is_supported).unwrap();
+      let test_files = fs_util::collect_files(&[p], &[], is_supported).unwrap();
       let test_files_as_urls = test_files
         .iter()
         .map(|f| Url::from_file_path(f).unwrap())