add --no-fetch CLI flag to prevent remote downloads (#2213)

4 files changed, 91 insertions, 20 deletions

diff --git a/cli/deno_dir.rs b/cli/deno_dir.rs
index e38d454e1..5b7b65f4b 100644
--- a/cli/deno_dir.rs
+++ b/cli/deno_dir.rs
@@ -156,6 +156,7 @@ impl DenoDir {
     specifier: &str,
     referrer: &str,
     use_cache: bool,
+    no_fetch: bool,
   ) -> impl Future<Item = ModuleMetaData, Error = errors::DenoError> {
     debug!(
       "fetch_module_meta_data. specifier {} referrer {}",
@@ -184,6 +185,7 @@ impl DenoDir {
         module_name.as_str(),
         filename.as_str(),
         use_cache,
+        no_fetch,
       ).then(move |result| {
         let mut out = match result {
           Ok(out) => out,
@@ -257,9 +259,11 @@ impl DenoDir {
     specifier: &str,
     referrer: &str,
     use_cache: bool,
+    no_fetch: bool,
   ) -> Result<ModuleMetaData, errors::DenoError> {
     tokio_util::block_on(
-      self.fetch_module_meta_data_async(specifier, referrer, use_cache),
+      self
+        .fetch_module_meta_data_async(specifier, referrer, use_cache, no_fetch),
     )
   }
 
@@ -364,7 +368,7 @@ impl DenoDir {
 
 impl SourceMapGetter for DenoDir {
   fn get_source_map(&self, script_name: &str) -> Option<Vec<u8>> {
-    match self.fetch_module_meta_data(script_name, ".", true) {
+    match self.fetch_module_meta_data(script_name, ".", true, true) {
       Err(_e) => None,
       Ok(out) => match out.maybe_source_map {
         None => None,
@@ -392,14 +396,16 @@ fn get_source_code_async(
   module_name: &str,
   filename: &str,
   use_cache: bool,
+  no_fetch: bool,
 ) -> impl Future<Item = ModuleMetaData, Error = DenoError> {
   let filename = filename.to_string();
   let module_name = module_name.to_string();
   let is_module_remote = is_remote(&module_name);
-  // We try fetch local. Two cases:
-  // 1. This is a remote module and we're allowed to use cached downloads.
-  // 2. This is a local module.
-  if !is_module_remote || use_cache {
+  // We try fetch local. Three cases:
+  // 1. Remote downloads are not allowed, we're only allowed to use cache.
+  // 2. This is a remote module and we're allowed to use cached downloads.
+  // 3. This is a local module.
+  if !is_module_remote || use_cache || no_fetch {
     debug!(
       "fetch local or reload {} is_module_remote {}",
       module_name, is_module_remote
@@ -419,7 +425,7 @@ fn get_source_code_async(
     }
   }
 
-  // If not remote file, stop here!
+  // If not remote file stop here!
   if !is_module_remote {
     debug!("not remote file stop here");
     return Either::A(futures::future::err(DenoError::from(
@@ -430,6 +436,17 @@ fn get_source_code_async(
     )));
   }
 
+  // If remote downloads are not allowed stop here!
+  if no_fetch {
+    debug!("remote file with no_fetch stop here");
+    return Either::A(futures::future::err(DenoError::from(
+      std::io::Error::new(
+        std::io::ErrorKind::NotFound,
+        format!("cannot find remote file '{}' in cache", &filename),
+      ),
+    )));
+  }
+
   debug!("is remote but didn't find module");
 
   // not cached/local, try remote.
@@ -454,12 +471,14 @@ fn get_source_code(
   module_name: &str,
   filename: &str,
   use_cache: bool,
+  no_fetch: bool,
 ) -> DenoResult<ModuleMetaData> {
   tokio_util::block_on(get_source_code_async(
     deno_dir,
     module_name,
     filename,
     use_cache,
+    no_fetch,
   ))
 }
 
@@ -1063,7 +1082,8 @@ mod tests {
       );
       let headers_file_name = source_code_headers_filename(&filename);
 
-      let result = get_source_code(&deno_dir, module_name, &filename, true);
+      let result =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
       assert!(result.is_ok());
       let r = result.unwrap();
       assert_eq!(
@@ -1077,7 +1097,8 @@ mod tests {
       // Modify .headers.json, write using fs write and read using save_source_code_headers
       let _ =
         fs::write(&headers_file_name, "{ \"mime_type\": \"text/javascript\" }");
-      let result2 = get_source_code(&deno_dir, module_name, &filename, true);
+      let result2 =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
       assert!(result2.is_ok());
       let r2 = result2.unwrap();
       assert_eq!(
@@ -1098,7 +1119,8 @@ mod tests {
         Some("application/json".to_owned()),
         None,
       );
-      let result3 = get_source_code(&deno_dir, module_name, &filename, true);
+      let result3 =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
       assert!(result3.is_ok());
       let r3 = result3.unwrap();
       assert_eq!(
@@ -1115,7 +1137,8 @@ mod tests {
       );
 
       // Don't use_cache
-      let result4 = get_source_code(&deno_dir, module_name, &filename, false);
+      let result4 =
+        get_source_code(&deno_dir, module_name, &filename, false, false);
       assert!(result4.is_ok());
       let r4 = result4.unwrap();
       let expected4 =
@@ -1141,7 +1164,8 @@ mod tests {
       );
       let headers_file_name = source_code_headers_filename(&filename);
 
-      let result = get_source_code(&deno_dir, module_name, &filename, true);
+      let result =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
       assert!(result.is_ok());
       let r = result.unwrap();
       let expected = "export const loaded = true;\n".as_bytes();
@@ -1159,7 +1183,8 @@ mod tests {
         Some("text/typescript".to_owned()),
         None,
       );
-      let result2 = get_source_code(&deno_dir, module_name, &filename, true);
+      let result2 =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
       assert!(result2.is_ok());
       let r2 = result2.unwrap();
       let expected2 = "export const loaded = true;\n".as_bytes();
@@ -1170,7 +1195,8 @@ mod tests {
       assert!(fs::read_to_string(&headers_file_name).is_err());
 
       // Don't use_cache
-      let result3 = get_source_code(&deno_dir, module_name, &filename, false);
+      let result3 =
+        get_source_code(&deno_dir, module_name, &filename, false, false);
       assert!(result3.is_ok());
       let r3 = result3.unwrap();
       let expected3 = "export const loaded = true;\n".as_bytes();
@@ -1211,6 +1237,7 @@ mod tests {
         redirect_module_name,
         &redirect_source_filename,
         true,
+        false,
       ).unwrap();
       // File that requires redirection is not downloaded.
       assert!(fs::read_to_string(&redirect_source_filename).is_err());
@@ -1271,6 +1298,7 @@ mod tests {
         redirect_module_name,
         &redirect_source_filename,
         true,
+        false,
       ).unwrap();
 
       // File that requires redirection is not downloaded.
@@ -1307,6 +1335,37 @@ mod tests {
   }
 
   #[test]
+  fn test_get_source_code_no_fetch() {
+    let (_temp_dir, deno_dir) = test_setup();
+    tokio_util::init(|| {
+      let module_name = "http://localhost:4545/tests/002_hello.ts";
+      let filename = deno_fs::normalize_path(
+        deno_dir
+          .deps_http
+          .join("localhost_PORT4545/tests/002_hello.ts")
+          .as_ref(),
+      );
+
+      // file hasn't been cached before and remote downloads are not allowed
+      let result =
+        get_source_code(&deno_dir, module_name, &filename, true, true);
+      assert!(result.is_err());
+      let err = result.err().unwrap();
+      assert_eq!(err.kind(), ErrorKind::NotFound);
+
+      // download and cache file
+      let result =
+        get_source_code(&deno_dir, module_name, &filename, true, false);
+      assert!(result.is_ok());
+
+      // module is already cached, should be ok even with `no_fetch`
+      let result =
+        get_source_code(&deno_dir, module_name, &filename, true, true);
+      assert!(result.is_ok());
+    });
+  }
+
+  #[test]
   fn test_fetch_source_async_1() {
     use crate::tokio_util;
     // http_util::fetch_sync_string requires tokio
@@ -1480,13 +1539,13 @@ mod tests {
       // Test failure case.
       let specifier = "hello.ts";
       let referrer = add_root!("/baddir/badfile.ts");
-      let r = deno_dir.fetch_module_meta_data(specifier, referrer, true);
+      let r = deno_dir.fetch_module_meta_data(specifier, referrer, true, false);
       assert!(r.is_err());
 
       // Assuming cwd is the deno repo root.
       let specifier = "./js/main.ts";
       let referrer = cwd_string.as_str();
-      let r = deno_dir.fetch_module_meta_data(specifier, referrer, true);
+      let r = deno_dir.fetch_module_meta_data(specifier, referrer, true, false);
       assert!(r.is_ok());
     })
   }
@@ -1503,13 +1562,15 @@ mod tests {
       // Test failure case.
       let specifier = "hello.ts";
       let referrer = add_root!("/baddir/badfile.ts");
-      let r = deno_dir.fetch_module_meta_data(specifier, referrer, false);
+      let r =
+        deno_dir.fetch_module_meta_data(specifier, referrer, false, false);
       assert!(r.is_err());
 
       // Assuming cwd is the deno repo root.
       let specifier = "./js/main.ts";
       let referrer = cwd_string.as_str();
-      let r = deno_dir.fetch_module_meta_data(specifier, referrer, false);
+      let r =
+        deno_dir.fetch_module_meta_data(specifier, referrer, false, false);
       assert!(r.is_ok());
     })
   }
diff --git a/cli/flags.rs b/cli/flags.rs
index d66c9528c..380c87b90 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -22,6 +22,7 @@ pub struct DenoFlags {
   pub allow_run: bool,
   pub allow_high_precision: bool,
   pub no_prompts: bool,
+  pub no_fetch: bool,
   pub v8_flags: Option<Vec<String>>,
 }
 
@@ -71,6 +72,10 @@ pub fn create_cli_app<'a, 'b>() -> App<'a, 'b> {
         .long("no-prompt")
         .help("Do not use prompts"),
     ).arg(
+      Arg::with_name("no-fetch")
+        .long("no-fetch")
+        .help("Do not download remote modules"),
+    ).arg(
       Arg::with_name("log-debug")
         .short("D")
         .long("log-debug")
@@ -242,6 +247,9 @@ pub fn parse_flags(matches: ArgMatches) -> DenoFlags {
   if matches.is_present("no-prompt") {
     flags.no_prompts = true;
   }
+  if matches.is_present("no-fetch") {
+    flags.no_fetch = true;
+  }
   if matches.is_present("v8-options") {
     let v8_flags = svec!["deno", "--help"];
     flags.v8_flags = Some(v8_flags);
diff --git a/cli/ops.rs b/cli/ops.rs
index b75140dcc..b2b9b4245 100644
--- a/cli/ops.rs
+++ b/cli/ops.rs
@@ -442,13 +442,14 @@ fn op_fetch_module_meta_data(
   assert_eq!(state.dir.root.join("gen"), state.dir.gen, "Sanity check");
 
   let use_cache = !state.flags.reload;
+  let no_fetch = state.flags.no_fetch;
 
   Box::new(futures::future::result(|| -> OpResult {
     let builder = &mut FlatBufferBuilder::new();
     // TODO(ry) Use fetch_module_meta_data_async.
     let out = state
       .dir
-      .fetch_module_meta_data(specifier, referrer, use_cache)?;
+      .fetch_module_meta_data(specifier, referrer, use_cache, no_fetch)?;
     let data_off = builder.create_vector(out.source_code.as_slice());
     let msg_args = msg::FetchModuleMetaDataResArgs {
       module_name: Some(builder.create_string(&out.module_name)),
diff --git a/cli/worker.rs b/cli/worker.rs
index 8b420cef6..317b104a0 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -211,12 +211,13 @@ fn fetch_module_meta_data_and_maybe_compile_async(
   referrer: &str,
 ) -> impl Future<Item = ModuleMetaData, Error = DenoError> {
   let use_cache = !state.flags.reload;
+  let no_fetch = state.flags.no_fetch;
   let state_ = state.clone();
   let specifier = specifier.to_string();
   let referrer = referrer.to_string();
   state
     .dir
-    .fetch_module_meta_data_async(&specifier, &referrer, use_cache)
+    .fetch_module_meta_data_async(&specifier, &referrer, use_cache, no_fetch)
     .and_then(move |out| {
       if out.media_type == msg::MediaType::TypeScript
         && !out.has_output_code_and_source_map()