Add --prefetch flag for deps prefetch without running

libdeno/api.cc

@@ -127,7 +127,7 @@ int deno_execute(Deno* d_, void* user_data, const char* js_filename,
 }
 
 int deno_execute_mod(Deno* d_, void* user_data, const char* js_filename,
-                     const char* js_source) {
+                     const char* js_source, int resolve_only) {
   auto* d = unwrap(d_);
   deno::UserDataScope user_data_scope(d, user_data);
   auto* isolate = d->isolate_;
@@ -136,7 +136,8 @@ int deno_execute_mod(Deno* d_, void* user_data, const char* js_filename,
   v8::HandleScope handle_scope(isolate);
   auto context = d->context_.Get(d->isolate_);
   CHECK(!context.IsEmpty());
-  return deno::ExecuteMod(context, js_filename, js_source) ? 1 : 0;
+  return deno::ExecuteMod(context, js_filename, js_source, resolve_only) ? 1
+                                                                         : 0;
 }
 
 int deno_respond(Deno* d_, void* user_data, int32_t req_id, deno_buf buf) {

libdeno/binding.cc

@@ -590,7 +590,7 @@ void DenoIsolate::ResolveOk(const char* filename, const char* source) {
 }
 
 bool ExecuteMod(v8::Local<v8::Context> context, const char* js_filename,
-                const char* js_source) {
+                const char* js_source, bool resolve_only) {
   auto* isolate = context->GetIsolate();
   v8::Isolate::Scope isolate_scope(isolate);
   v8::HandleScope handle_scope(isolate);
@@ -616,6 +616,11 @@ bool ExecuteMod(v8::Local<v8::Context> context, const char* js_filename,
   }
 
   CHECK_EQ(v8::Module::kInstantiated, module->GetStatus());
+
+  if (resolve_only) {
+    return true;
+  }
+
   auto result = module->Evaluate(context);
 
   if (result.IsEmpty()) {

libdeno/deno.h

@@ -75,8 +75,11 @@ int deno_execute(Deno* d, void* user_data, const char* js_filename,
 // when instantiating the Deno object.
 // Return value: 0 = fail, 1 = success
 // Get error text with deno_last_exception().
+// If resolve_only is 0, compile and evaluate the module.
+// If resolve_only is 1, compile and collect dependencies of the module
+// without running the code.
 int deno_execute_mod(Deno* d, void* user_data, const char* js_filename,
-                     const char* js_source);
+                     const char* js_source, int resolve_only);
 
 // deno_respond sends up to one message back for every deno_recv_cb made.
 //

libdeno/internal.h

@@ -145,7 +145,7 @@ void DeleteDataRef(DenoIsolate* d, int32_t req_id);
 bool Execute(v8::Local<v8::Context> context, const char* js_filename,
              const char* js_source);
 bool ExecuteMod(v8::Local<v8::Context> context, const char* js_filename,
-                const char* js_source);
+                const char* js_source, bool resolve_only);
 
 }  // namespace deno
 

libdeno/libdeno_test.cc

@@ -284,7 +284,7 @@ TEST(LibDenoTest, ModuleResolution) {
     deno_resolve_ok(d, "b.js", mod_b);
   };
   Deno* d = deno_new(deno_config{0, empty, empty, nullptr, resolve_cb});
-  EXPECT_TRUE(deno_execute_mod(d, d, "a.js", mod_a));
+  EXPECT_TRUE(deno_execute_mod(d, d, "a.js", mod_a, false));
   EXPECT_EQ(count, 1);
   deno_delete(d);
 }
@@ -299,7 +299,7 @@ TEST(LibDenoTest, ModuleResolutionFail) {
     // Do not call deno_resolve_ok();
   };
   Deno* d = deno_new(deno_config{0, empty, empty, nullptr, resolve_cb});
-  EXPECT_FALSE(deno_execute_mod(d, d, "a.js", mod_a));
+  EXPECT_FALSE(deno_execute_mod(d, d, "a.js", mod_a, false));
   EXPECT_EQ(count, 1);
   deno_delete(d);
 }
@@ -309,7 +309,8 @@ TEST(LibDenoTest, ModuleSnapshot) {
   EXPECT_TRUE(deno_execute_mod(d1, nullptr, "x.js",
                                "const globalEval = eval\n"
                                "const global = globalEval('this')\n"
-                               "global.a = 1 + 2"));
+                               "global.a = 1 + 2",
+                               0));
   deno_buf test_snapshot = deno_get_snapshot(d1);
   deno_delete(d1);
 
@@ -321,12 +322,32 @@ TEST(LibDenoTest, ModuleSnapshot) {
   deno_delete(d2);
 
   Deno* d3 = deno_new(config);
-  EXPECT_TRUE(deno_execute_mod(d3, nullptr, "y.js", y_src));
+  EXPECT_TRUE(deno_execute_mod(d3, nullptr, "y.js", y_src, false));
   deno_delete(d3);
 
   delete[] test_snapshot.data_ptr;
 }
 
+TEST(LibDenoTest, ModuleResolveOnly) {
+  static int count = 0;
+  auto resolve_cb = [](void* user_data, const char* specifier,
+                       const char* referrer) {
+    EXPECT_STREQ(specifier, "b.js");
+    EXPECT_STREQ(referrer, "a.js");
+    count++;
+    auto d = reinterpret_cast<Deno*>(user_data);
+    deno_resolve_ok(d, "b.js", mod_b);
+  };
+  Deno* d = deno_new(deno_config{0, empty, empty, nullptr, resolve_cb});
+  // Code should not execute. If executed, the error would be thrown
+  EXPECT_TRUE(deno_execute_mod(d, d, "a.js",
+                               "import { retb } from 'b.js'\n"
+                               "throw Error('unreachable');",
+                               true));
+  EXPECT_EQ(count, 1);
+  deno_delete(d);
+}
+
 TEST(LibDenoTest, BuiltinModules) {
   static int count = 0;
   auto resolve_cb = [](void* user_data, const char* specifier,
@@ -347,7 +368,8 @@ TEST(LibDenoTest, BuiltinModules) {
                        "import * as deno from 'deno'\n"
                        "if (retb() != 'b') throw Error('retb');\n"
                        // "   libdeno.print('deno ' + JSON.stringify(deno));\n"
-                       "if (deno.foo != 'bar') throw Error('foo');\n"));
+                       "if (deno.foo != 'bar') throw Error('foo');\n",
+                       false));
   EXPECT_EQ(count, 1);
   deno_delete(d);
 }

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();
 

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();
     });
   }

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,

src/main.rs

@@ -100,6 +100,8 @@ 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);
@@ -114,7 +116,7 @@ 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);
     }
 

tools/integration_tests.py

@@ -11,10 +11,7 @@
 import re
 import sys
 import subprocess
-from util import pattern_match, green_ok, red_failed
-
-root_path = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
-tests_path = os.path.join(root_path, "tests")
+from util import root_path, tests_path, pattern_match, green_ok, red_failed
 
 
 def read_test(file_name):

tools/prefetch_test.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+# Copyright 2018 the Deno authors. All rights reserved. MIT license.
+import os
+import sys
+from util import tests_path, run_output, build_path, executable_suffix, green_ok
+import tempfile
+import shutil
+
+
+def prefetch_test(deno_exe):
+    sys.stdout.write("prefetch_test...")
+    sys.stdout.flush()
+
+    # On Windows, set the base directory that mkdtemp() uses explicitly. If not,
+    # it'll use the short (8.3) path to the temp dir, which triggers the error
+    # 'TS5009: Cannot find the common subdirectory path for the input files.'
+    temp_dir = os.environ["TEMP"] if os.name == 'nt' else None
+    deno_dir = tempfile.mkdtemp(dir=temp_dir)
+    try:
+        t = os.path.join(tests_path, "006_url_imports.ts")
+        output = run_output([deno_exe, "--prefetch", t],
+                            merge_env={"DENO_DIR": deno_dir})
+        assert output == ""
+        # Check that we actually did the prefetch.
+        os.path.exists(
+            os.path.join(deno_dir,
+                         "deps/http/localhost_PORT4545/tests/subdir/mod2.ts"))
+    finally:
+        shutil.rmtree(deno_dir)
+
+    print green_ok()
+
+
+if __name__ == "__main__":
+    prefetch_test(sys.argv[1])

tools/test.py

@@ -12,6 +12,7 @@
 from util_test import util_test
 from benchmark_test import benchmark_test
 from repl_test import repl_tests
+from prefetch_test import prefetch_test
 import subprocess
 import http_server
 
@@ -59,6 +60,8 @@ def main(argv):
 
     unit_tests(deno_exe)
 
+    prefetch_test(deno_exe)
+
     integration_tests(deno_exe)
 
     # TODO We currently skip testing the prompt in Windows completely.

tools/util.py

@@ -12,6 +12,7 @@
 
 executable_suffix = ".exe" if os.name == "nt" else ""
 root_path = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+tests_path = os.path.join(root_path, "tests")
 
 
 def make_env(merge_env=None, env=None):