feat: add deno test --watch (#9160)

This commit implements file watching for deno test.

When a file is changed, only the test modules which 
use it as a dependency are rerun.

This is accomplished by reworking the file watching infrastructure 
to pass the paths which have changed to the resolver, and then 
constructing a module graph for each test module to check if it 
contains any changed files.

1 files changed, 7 insertions, 0 deletions

diff --git a/cli/flags.rs b/cli/flags.rs
index 0c916ecb8..6f23afba1 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -1031,6 +1031,11 @@ fn test_subcommand<'a, 'b>() -> App<'a, 'b> {
         .takes_value(true)
         .multiple(true),
     )
+    .arg(
+      watch_arg()
+        .conflicts_with("no-run")
+        .conflicts_with("coverage"),
+    )
     .arg(script_arg().last(true))
     .about("Run tests")
     .long_about(
@@ -1667,6 +1672,8 @@ fn test_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   let quiet = matches.is_present("quiet");
   let filter = matches.value_of("filter").map(String::from);
 
+  flags.watch = matches.is_present("watch");
+
   if matches.is_present("script_arg") {
     let script_arg: Vec<String> = matches
       .values_of("script_arg")