Add --prefetch flag for deps prefetch without running (#1475)

4 files changed, 18 insertions, 3 deletions

diff --git a/src/flags.rs b/src/flags.rs
index f2d0150b1..970aceb3c 100644
--- a/src/flags.rs
+++ b/src/flags.rs
@@ -28,6 +28,7 @@ pub struct DenoFlags {
   pub allow_env: bool,
   pub allow_run: bool,
   pub types: bool,
+  pub prefetch: bool,
 }
 
 pub fn get_usage(opts: &Options) -> String {
@@ -107,6 +108,9 @@ fn set_recognized_flags(
         if matches.opt_present("types") {
           flags.types = true;
         }
+        if matches.opt_present("prefetch") {
+          flags.prefetch = true;
+        }
 
         if !matches.free.is_empty() {
           rest.extend(matches.free);
@@ -142,6 +146,7 @@ pub fn set_flags(
   opts.optflag("r", "reload", "Reload cached remote resources.");
   opts.optflag("", "v8-options", "Print V8 command line options.");
   opts.optflag("", "types", "Print runtime TypeScript declarations.");
+  opts.optflag("", "prefetch", "Prefetch the dependencies.");
 
   let mut flags = DenoFlags::default();
 
diff --git a/src/isolate.rs b/src/isolate.rs
index 9c9e7dd4f..bbd52c64d 100644
--- a/src/isolate.rs
+++ b/src/isolate.rs
@@ -254,7 +254,11 @@ impl Isolate {
   }
 
   /// Executes the provided JavaScript module.
-  pub fn execute_mod(&self, js_filename: &str) -> Result<(), JSError> {
+  pub fn execute_mod(
+    &self,
+    js_filename: &str,
+    is_prefetch: bool,
+  ) -> Result<(), JSError> {
     let out =
       code_fetch_and_maybe_compile(&self.state, js_filename, ".").unwrap();
 
@@ -271,6 +275,7 @@ impl Isolate {
         self.as_raw_ptr(),
         filename_ptr,
         js_source_ptr,
+        if is_prefetch { 1 } else { 0 },
       )
     };
     if r == 0 {
@@ -662,7 +667,9 @@ mod tests {
     let snapshot = libdeno::deno_buf::empty();
     let isolate = Isolate::new(snapshot, state, dispatch_sync);
     tokio_util::init(|| {
-      isolate.execute_mod(filename).expect("execute_mod error");
+      isolate
+        .execute_mod(filename, false)
+        .expect("execute_mod error");
       isolate.event_loop().ok();
     });
   }
diff --git a/src/libdeno.rs b/src/libdeno.rs
index 40a5a51d0..f8f8a61e0 100644
--- a/src/libdeno.rs
+++ b/src/libdeno.rs
@@ -151,6 +151,7 @@ extern "C" {
     user_data: *const c_void,
     js_filename: *const c_char,
     js_source: *const c_char,
+    resolve_only: i32,
   ) -> c_int;
   pub fn deno_resolve_ok(
     i: *const isolate,
diff --git a/src/main.rs b/src/main.rs
index a9c3f42f0..d6188ef62 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -79,6 +79,8 @@ fn main() {
     log::LevelFilter::Warn
   });
 
+  let should_prefetch = flags.prefetch;
+
   let state = Arc::new(isolate::IsolateState::new(flags, rest_argv, None));
   let snapshot = snapshot::deno_snapshot();
   let isolate = isolate::Isolate::new(snapshot, state, ops::dispatch);
@@ -93,7 +95,7 @@ fn main() {
     if isolate.state.argv.len() > 1 {
       let input_filename = &isolate.state.argv[1];
       isolate
-        .execute_mod(input_filename)
+        .execute_mod(input_filename, should_prefetch)
         .unwrap_or_else(print_err_and_exit);
     }